Teledyne 913 Operating instructions

Power Products Guide
Installation and Operation Guide
Part #60-9003-092
Copyright © 2002. All rights reserved, Teledyne Isco, Inc.
Revision T, November 2017

Foreword
This instruction manual is designed to help you gain a thorough understanding of the operation of
the equipment. Teledyne Isco recommends that you read this manual completely before placing the
equipment in service.
Although Teledyne Isco designs reliability into all equipment, there is always the possibility of a
malfunction. This manual may help in diagnosing and repairing the malfunction.
If a problem persists, call or e-mail Teledyne Isco technical support for assistance. Simple
difficulties can often be diagnosed over the phone. For faster service, please have your serial
number ready.
If it is necessary to return the equipment to the factory for service, please follow the shipping
instructions provided by technical support, including the use of the Return Material
Authorization (RMA) specified. Be sure to include a note describing the malfunction. This will
aid in the prompt repair and return of the equipment.
Teledyne Isco welcomes suggestions that would improve the information presented in this manual
or enhance the operation of the equipment itself.
Teledyne Isco is continually improving its products and reserves the right to change product
specifications, replacement parts, schematics, and instructions without notice.
Contact Information
Customer Service
Phone: [phone] (USA, Canada, Mexico)
[phone] (Outside North America)
Fax: [phone]
Email: [email protected]
Technical Support
Phone: Toll Free [phone] (Syringe Pumps and Liquid Chromatography)
Email: [email protected]
Return equipment to: 4700 Superior Street, Lincoln, NE 68504-1398
Other Correspondence
Mail to: P.O. Box 82531, Lincoln, NE 68501-2531
Email: [email protected]

i
Power Products Guide
Table of Contents
Section 1 Introduction
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2 Model Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3 Compatibility of Batteries and Chargers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Section 2 Batteries
2.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.1 Battery Recycling and Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.2 Battery Ratings (Ampere-Hours) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.1.3 Determining Life Expectancy of Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.4 Charged and Discharged Cell Voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.5 Self-Discharge of Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
2.2 Model 934 Nickel-Cadmium Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
2.2.1 Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
2.2.2 Charging Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
2.2.3 Avoiding Self-Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
2.2.4 Effects of Overcharging the Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
2.2.5 Using Other Battery Chargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
2.2.6 “Memory” Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
2.2.7 Servicing the Nickel-Cadmium Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
2.2.8 Replacement of the Battery Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
2.3 Model 946 Lead-Acid Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
2.3.1 Charging Lead-Acid Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
2.3.2 Using Other Battery Chargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
2.4 Model 948 Lead-Acid Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
2.5 Use of Other Types of Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.5.1 Alkaline (Nonrechargeable) Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.5.2 Deep-Cycle R-V or Marine Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.5.3 Maintenance and Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.5.4 Hazard of Short Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Section 3 Batteries for Flow Loggers
3.1 Internally Mounted Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2 Model 947 Lead-Acid Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.3 Alkaline “Lantern” Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.4 Flow Loggers - External Power Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Section 4 Isco Battery Chargers and Power Packs
4.1 Isco Chargers and Power Packs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.2 Model 961 Battery Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.3 Model 963 Battery Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.4 Model 913 and 923 High Capacity Power Packs . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.5 Models 914 and 924 Battery-Backed Power Packs . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.6 Model 965 Five-Station Battery Charger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
4.7 Solar Panel Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Power Products Guide
Table of Contents
ii
Appendix A Power Product Part Numbers
A.1 Part Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Appendix B Material Safety Data Sheets
B.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
List of Figures
2-1 Model 934 Nickel-Cadmium Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
2-2 Model 946 Lead-Acid Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
2-3 Model 948 Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2-4 Model 948 Battery Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
3-1 Model 947 Flow Logger Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3-2 Flow Logger Alkaline Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
4-1 Model 961 Wall Charger for Nickel-Cadmium Batteries . . . . . . . . . . . . . . . . . . . . 4-1
4-2 Model 963 Battery Charger for Lead-Acid Batteries . . . . . . . . . . . . . . . . . . . . . . . 4-2
4-3 Model 913 High Capacity Power Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4-4 Model 914 Battery-Backed Power Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4-5 Model 965 Five-Station Battery Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
4-6 Solar Panel Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
List of Tables
1-1 Battery/Charger Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
A-1 Power Product Part Numbers and Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . A-2

1-1
Power Products Guide
Section 1 Introduction
1.1 Overview This guide provides information about the power sources that are
available for Isco products.
Teledyne Isco offers rechargeable lead-acid and nickel-cadmium
batteries, and also makes power supplies that convert 120 volt
AC power to 12 volts DC. This guide provides information about
the rechargeable batteries and descriptions of the AC power
packs.
Some power products have manuals of their own. Those products
are shipped with their own manuals. Products that have their
own manuals are discussed only briefly here.
1.2 Model Numbers Teledyne Isco has assigned model numbers to most power
products. The three-digit model numbers start with 9XX.
•The910 series are 120-volt high capacity power packs
and battery-backed power packs:
·Model 913–High Capacity Power Pack, 120 VAC
·Model 914–Battery Backed Power Pack, 120 VAC
•The920 series are 240-volt high capacity power packs
and battery-backed power packs.
·Model 923–High Capacity Power Pack, 240V
·Model 924–Battery Backed Power Pack, 240V
•The930 series are rechargeable nickel-cadmium
batteries.
·Model 934–Nickel-Cadmium Battery 12V, 4.0 Ah
Note that “Ah” stands for ampere-hours, the standard
rating that battery manufacturers use to describe bat-
tery capacity. (See Section 2 for a more thorough
description.)
•The940 series are sealed rechargeable lead-acid
batteries.
·Model 946–Lead-Acid Battery 12V, 6.5 Ah
·Model 947–Lead-Acid Battery 12V, 6.5 Ah (for the
4100 Series Flow Loggers)
·Model 948–Lead-Acid Battery 12V, 55 Ah
•Solar panels are used to charge Isco lead-acid
batteries.
•The960 series are battery chargers.
·Model 961–Wall Charger for Nickel-Cadmium
Batteries - 120 VAC, 400 mA output

Power Products Guide
Section 1 Introduction
1-2
·Model 963–Desktop Single Station Lead-Acid
Battery Charger - for lead-acid batteries, 120 or 230
VAC
·Model 965–Five Station Battery Charger - for one to
five lead-acid or nickel-cadmium batteries, 120 or 240
VAC.
1.3 Compatibility of
Batteries and Chargers
Refer to Table 1-1 below to check the compatibility of various Isco
batteries and chargers.
Table 1-1 Battery/Charger Compatibility
Model of Battery
Model of Charger 934 946 947 948
Solar Panel nnn
961 n
963 nn
965 nnn
Automatic Charger n
Model of Power Pack
913 no
914 no charger no charger
923 no
924 no charger no charger
n Recommended
oPossible when following the instructions printed on the side of the battery.

2-1
Power Products Guide
Section 2 Batteries
2.1 General Information Teledyne Isco offers two different batteries for use with its
equipment. Both batteries fit inside of or on top of Isco
equipment and fasten to the equipment with rubber draw
catches. Both have advantages and disadvantages. The choice is
ultimately up to you.
The most common battery is the Isco Model 934
Nickel-Cadmium Battery, which is described in Section 2.2.
Each cell in the nickel-cadmium battery provides 1.2 VDC and
has a capacity of 4 ampere-hours (Ah). It takes ten of these cells
connected in series to make a battery of 12 volts. The cells are
packaged in an environmentally-sealed plastic housing, supplied
with a cable and two-pin M/S connector, and provide 12 volts DC.
Also available is the Isco Model 946 Lead-Acid Battery,
described in Section 2.3. This battery is a six-cell, plastic-cased,
6.5 Ah, gelled-electrolyte type, supplied with a connector. It
delivers 12 volts. A lead-acid cell provides 2.2 volts, so six are
required for 12 volts. These batteries are popularly known as
gel-cells.
2.1.1 Battery Recycling and
Disposal
Batteries of all types are a significant source of toxic and envi-
ronmentally hazardous materials, primarily heavy metals. The
disposal of lead-acid, nickel-cadmium, and alkaline batteries in
landfills every year represents a growing threat to the envi-
ronment. Legislation requiring the recycling and/or proper dis-
posal of rechargeable batteries has been passed in most states.
Because the laws vary from state to state, and in each locality, it
is your responsibility to find out how to recycle or dispose of these
products properly.
Since July 1, 1993, we have labeled all equipment containing bat-
teries with the three-arrow recycling logo and the type of battery
(Ni-Cd [nickel-cadmium] or Pb [lead-acid]).

Power Products Guide
Section 2 Batteries
2-2
2.1.2 Battery Ratings
(Ampere-Hours)
Battery manufacturers rate the capacity of batteries in
ampere-hours, (availability of current over time). Typically,
manufacturers rate battery capacity at a certain current over a
specific period of time. The product of this value is the
ampere-hour rating of the battery.
Typical ratings for the discharge of nickel-cadmium batteries are
over 10 hours and for lead-acid batteries are over 20 hours. As
a result, a rating of 4 or 6.5 ampere-hours for a battery does not
mean you can draw 4 or 6.5 amperes from the battery for one
hour. The actual amount at the one-hour rate is typically
one-half the “rated” capacity of the battery, or less. To determine
the actual battery rating, you must take the nominal capacity
(4 or 6.5 ampere-hours) and divide it by 10 or 20, depending on
the battery type.
In the case of the Model 934 Nickel-Cadmium Battery, you use a
figure of 0.4, and for the Model 946 Lead-Acid Battery you will
use 0.325. Customarily, currents below 1.0 ampere are expressed
in milliamperes (mA). This means you can expect to discharge
the nickel-cadmium battery at 400 mA for 10 hours. You would
expect to discharge the lead-acid battery at 325 mA for 20 hours.
Battery manufacturers provide curves in their literature
showing the discharge rates in percentages of “C,” which stands
for rated capacity in ampere-hours (Ah). If you discharge the
battery at rates greater than the 20-hour rate, you can draw
more current, but for a considerably shorter time; that is, the
value of time multiplied by current will amount to much less
than “C.” For more than 20 hours, you can draw less current for a
longer time.
For times beyond 20 hours, the product of current and time will
amount to more than “C,” at least, up to a point. The value of
“C,” or more likely a percentage of it, is also used to describe the
proper charging current for a battery.
“C” is useful for determining how long you can power an Isco
instrument from a particular battery. Teledyne Isco provides
average current consumption figures for most equipment. You
can use these figures as a rough estimate to calculate the
expected life of a battery connected to that equipment.
The product you have purchased contains a rechargeable battery.
This battery is recyclable. Disposal of this battery at the end of its
useful life in the municipal waste stream may be illegal, depending
on the laws of your state or locality. Check with solid waste officials
in your area for information on recycling options or proper disposal.

Power Products Guide
Section 2 Batteries
2-3
2.1.3 Determining Life
Expectancy of Charge
In this example, a flow meter has an average current draw of 26
mA. We want to power it with an Isco Nickel-Cadmium Battery.
The battery has a capacity of 4.0 Ah. First, convert 4.0 Ah into
4,000 mA-h (milliampere-hours). Then divide 4,000 mA-h by 26
mA. The result is 153.8 hours. Dividing 153.8 by 24 (hours/day),
we get 6.41, or almost 61/2days. Note that you convert the
battery ampere-hour rating to milliampere-hours to make the
rating match the equipment current rating, which is in milliam-
peres. If you prefer, you could leave the battery value in
ampere-hours and convert the flow meter current rating from 26
mA to 0.026 amperes.
If you want to use the Isco Lead-Acid Battery, you would convert
the ampere-hour rating from 6.5 A-h to 6,500 mA-h, and divide
that by 26 mA to get 250 hours. Dividing 250 by 24, we get 10.4
days.
Note that the figures given for current consumption for various
Isco products are average figures based on very specific oper-
ating conditions (for flow meters), such as a bubble rate of one
bubble per second and a chart advance rate of one inch per hour.
If you set the chart advance faster, or increase the bubble rate,
the current consumption will increase.
In the same way, current consumption for a sampler depends on
how often the unit takes a sample. That will vary widely from
one sampling program to another. Note that the current figures
supplied are average currents, meaning that when the plotter
or the pump run, peak current consumption will be consid-
erably greater.
The important issue here is to be aware that current con-
sumption for your equipment will depend largely on your pro-
gramming choices. Teledyne Isco cannot guarantee a specific
current consumption for a product, because programming flexi-
bility has so great an effect on it. You may have to experiment for
some time to match the battery life expectancy with your pro-
gramming choices.
2.1.4 Charged and
Discharged Cell
Voltages
When fully charged, a nickel-cadmium battery tests 1.2 to 1.3
volts per cell. A lead-acid battery shows 2.2 to 2.3 volts per cell.
A nickel-cadmium cell is considered fully discharged below
1.0 volt. A lead-acid battery is considered fully discharged at
1.75 volts per cell. Both values are at normal (room) tempera-
tures. You can see from these figures that a “dead” battery will
not really be dead, with both batteries showing at least 10 volts
left in them. Why not discharge this capacity to zero?
The answer lies in the fact that batteries are chemical in nature.
Chemical reactions inside the cells provide the source of elec-
tricity. Discharging a battery to zero volts risks having either of
two serious things occur. One is damage to the cell’s plates from
depletion of the active elements; the other is cell reversal.
Because no two cells in a battery are identical, discharge occurs
at different rates inside each cell. One cell usually reaches
depletion before the others. If you continue to try to draw power
from the battery, the cells with remaining capacity will force

Power Products Guide
Section 2 Batteries
2-4
current through the cell, in effect, charging it backwards. This
amounts to the electrical reversal of the two poles of the cell, and
can ruin either type of battery.
In nickel-cadmium batteries, cell reversal causes gas generation,
and that may force the vents to open. In lead-acid batteries, the
reversed cell presents a high resistance to the rest of the circuit,
making recharging difficult. Finally, while the battery may show
nearly full terminal voltage, there is, in fact, very little current
capacity left in it.
2.1.5 Self-Discharge of
Batteries
Self-discharge is the characteristic of all batteries that makes
them run down completely over time, even though there is no
load attached. Self-discharge is the result of inevitable chemical
reactions occurring inside the cell. This characteristic is more
serious in some types of batteries than others.
Nickel-cadmium and the newer nickel-hydride batteries have
poor charge retention. Loss of as much as 1% per day of
remaining charge has been reported. On the positive side, com-
plete self-discharge of nickel-cadmium batteries does not perma-
nently harm them. Alkaline (primary) cells, (not rechargeable)
have very good charge retention, keeping most of their charge
for several years at moderate (room) temperatures. Lithium bat-
teries, also nonrechargeable and often used for memory backup,
have excellent charge retention, as long as ten years.
Lead-acid batteries have good charge retention, retaining
about 50% of capacity after one year when stored at room tem-
perature. However, you should never allow a lead-acid battery to
self-discharge completely. Unlike the nickel-cadmium battery,
complete self-discharge will generally ruin a lead-acid battery.
Because chemical reactions cause self-discharge, temperature
has an effect. Avoid storing batteries in hot environments. The
rate of chemical reaction doubles for every 10C increase in
temperature. Finally, note that the rate of self-discharge tends to
increase as the batteries age, especially for nickel-cadmium
types, while their ampere-hour capacity usually diminishes.
2.2 Model 934
Nickel-Cadmium
Battery
The Isco Model 934 Nickel-Cadmium Battery is the most
popular battery for Isco equipment. This battery offers advan-
tages over other types of batteries, particularly lead-acid types.
The number of charge/discharge cycles is quite high, as many as
500 or more, according to one manufacturer. A nickel-cadmium
battery can stay discharged indefinitely, even at very low temper-
atures, without sustaining damage. This condition would ruin a
lead-acid battery.

Power Products Guide
Section 2 Batteries
2-5
Figure 2-1 Model 934 Nickel-Cadmium Battery
The battery has an internal fuse, rated at approximately 50
amperes, to prevent the possibility of fire or burns in the event of
a short circuit. If the internal fuse link blows, you will have to
return the battery to the factory for repair.
CAUTION
Do not test these batteries for charge by “sparking” the output,
and be extremely careful putting meter probes inside the out-
put connector. Any accidents resulting in a shorted output will
damage the battery in less than three seconds.
One battery manufacturer states that the short-circuit discharge
rate from a fully-charged nickel-cadmium battery can be as much
as 50 to 100 times “C.” For the Isco Model 934 Battery, this
could be from 200 to 400 amperes of discharge current. Usually,
the resistance of the wires prevents so large a current from
leaving the battery, but it is a dangerous level, in any case. Cur-
rents this large can do extensive damage, mostly from the heat
generated. That is why the battery is fused.
2.2.1 Charging You can recharge the nickel-cadmium battery with an Isco Power
Pack, an Isco Battery Charger, or with the Model 965 Five
Station Battery Charger. All these provide the proper current
(400 mA) for charging the batteries. To charge the battery,
connect the plug on the battery cable to the mating receptacle on
the power pack, or the connector on the charger. Leave the
battery on charge for 15 to 18 hours. The Five-Station Battery
Charger lets you charge as many as five batteries at once, and
lets you charge both nickel-cadmium and lead-acid batteries,
although not at the same time.
CAUTION
Never charge any battery inside a sealed container or enclo-
sure. Charging may release gases from the electrolyte. These
gases can generate dangerous pressure as they try to escape

Power Products Guide
Section 2 Batteries
2-6
confinement from the cells or enclosure. The gases may be
explosive and they can also be irritating to smell.
All rechargeable batteries, whether nickel-cadmium or
lead-acid, have one-way safety vents that open to relieve inter-
nal pressure generated by overcharging or very heavy dis-
charge. Their purpose is to keep the battery from bursting,
catching fire, or even exploding.
These vents do not open during normal operation. If they do
open, it indicates battery abuse. Venting shortens battery life
by depleting irreplaceable electrolyte. Avoid causing any of the
conditions that can make this happen.
2.2.2 Charging Temperature One manufacturer of nickel-cadmium cells recommends charging
them within a temperature range of 32° F (0° C) to 110° F (45°
C). Below 32° F, charging increases the gas pressure within the
cell, and that may force the safety vent to open. Above 110° F,
charging efficiency decreases, and the high temperature accel-
erates deterioration of the plate separator material, hastening
end-of-life.
Measuring nickel-cadmium batteries shows an almost-constant
output voltage from charged to discharged. This is because the
electrolyte, water and potassium hydroxide (KOH), is not
depleted of ions (which affects conductivity) during discharge, as
is the electrolyte in lead-acid batteries. As a result, you cannot
measure the output voltage to calculate the remaining charge in
the battery. You can achieve the recommended 15-hour charging
interval by putting the battery on charge before leaving work in
the evening and then taking it off when you come in the next
morning (5 PM to 8 AM is 15 hours). As long as the battery is
accepting the charge, it will stay cool to the touch. When fully
charged, the battery will feel warm, as it dissipates the charging
current as heat. Discontinue charging when the battery feels
warm.
2.2.3 Avoiding
Self-Discharge
As mentioned, nickel-cadmium batteries have a higher rate of
self-discharge than other types of batteries. After charging,
always try to return the battery to service within a reasonable
period of time (one to two weeks at most), to ensure the avail-
ability of most of the battery's capacity. Self-discharge does not
affect the life or usability of nickel-cadmium batteries, and it
does not mean the batteries are bad. It just means that the bat-
teries will not deliver full-rated capacity if you do not return
them to service promptly after charging.
Do not store the batteries in a hot environment, such as a room
with a furnace, boiler, or heater, or in direct sunlight, if at all pos-
sible. The self-discharge characteristic seems to increase with
age, probably due to the deterioration of the plate separator
material and the growth of crystalline “whiskers” between the
plates.

Power Products Guide
Section 2 Batteries
2-7
We suggest you discontinue the use of “old” batteries. Rapid
self-discharge is often the actual cause of unreliability in older
batteries, not diminished capacity. The manufacturer of the cells
used in the Isco battery considers end-of-life to have occurred
when battery capacity has dropped to 80% of the rating for new
cells.
Finally, if you cannot return the battery to service immediately
or don't know the charge condition, simply “top off” the charge
for a few hours.
2.2.4 Effects of Overcharging
the Battery
Overcharging the nickel-cadmium battery causes the cells to
heat up. Over time this heating breaks down the separator
material used between the plates inside the cells, encouraging
the growth of the crystalline whiskers, causing shorts. Prolonged
overcharging will shorten the life of the cells; try to avoid it.
2.2.5 Using Other Battery
Chargers
Teledyne Isco does not recommend the use of chargers designed
for lead-acid batteries, such as automotive battery chargers. The
open-circuit voltage of lead-acid chargers is generally not high
enough to fully charge a nickel-cadmium battery, and these
chargers are usually not current-regulated. Neither does
Teledyne Isco recommend using chargers intended for other
types of nickel-cadmium batteries, especially the so-called
“fast-charge” types. These chargers are designed for use only
with compatible “fast-charge” cells and can charge the proper
batteries in as little as one hour (1.0 “C”). Isco batteries use
“standard” cells intended for charging at 400 mA (0.1 “C”) for 15
to 18 hours. Chargers that provide more current than this may
cause overheating and that may force the safety vents to open,
releasing water. You cannot replace this water.
Chargers that deliver too little current to the batteries may
never charge them to full capacity, and may themselves be
damaged from the overload. Do not attempt to use any other
charging apparatus without an accurate digital multimeter to
monitor the charging current. If the charger delivers more than
600 mA, Teledyne Isco recommends you do not use it. If it
delivers less than 100 mA, the charging period becomes too long.
Even then the battery may never recharge completely. Be sure
of proper polarity before connecting any other charging
apparatus! If you use an Isco Power Pack, you can overcharge
the battery occasionally with little loss of capacity. However, you
should avoid chronic or prolonged overcharging. Again, return
the battery to service promptly.
2.2.6 “Memory” Effects For a long time, people believed that nickel-cadmium batteries
were subject to “memory” effects, and that a complete charge/dis-
charge cycle (exercising the battery) was necessary to maintain
battery capacity. “Memory” is the characteristic a battery may
develop of appearing to have lost some of its capacity after a few
shallow discharges.
The battery will only discharge to the same shallow point. It is
now known that the memory effect is not a problem with Isco
equipment under normal operating conditions, because most Isco

Power Products Guide
Section 2 Batteries
2-8
applications generally involve a deep or full discharge. If it does
occur, it is temporary, and you can reverse it by a deep discharge
and charge. If you discharge the battery to random depths,
charge for random amounts of time, and subject the battery to
various duty cycles, the memory effects will not be present.
2.2.7 Servicing the
Nickel-Cadmium
Battery
This section covers replacement of the connect cable. You can
make this repair yourself. However, some familiarity with elec-
trical/electronic repair procedures is necessary. You must know
how to solder, make proper splices, and insulate them safely. You
must follow the color codes used to maintain proper polarity on
the battery after the repair. If you are not familiar with these
procedures, or are uncomfortable doing them, return the battery
to Teledyne Isco for repair. If the fuse is all right and only the
cable needs replacing, Teledyne Isco suggests making the repair
after the battery has been discharged.
2.2.8 Replacement of the
Battery Cable
If the cable on the nickel-cadmium battery is damaged or inoper-
ative, you can replace it in the field. Remove the screws holding
the battery cover. Lift the cover from the case to reveal the cable
connections. To make replacement easier, the connections are
outside the potting wax. To replace the cable, simply cut away
the old cable and splices, one wire at a time, and solder in a
replacement. Carefully insulate the exposed wires with shrink
tubing (preferred) or electrical tape. Replace the battery case
cover and screws.
WARNING
When replacing a battery cable, be careful not to short the
leads from the battery together, or you may irreparably
damage the battery and you may also risk personal injury.
Insulate splices carefully. Replace only one wire at a time.
2.3 Model 946 Lead-Acid
Battery
While the nickel-cadmium battery has traditionally been the
usual battery for powering Isco products, Teledyne Isco also
offers a 6.5 ampere-hour gelled-electrolyte 12-volt lead-acid
battery (see Figure 2-2). Either battery will operate an Isco
sampler, flow meter, portable pump, or other equipment satisfac-
torily, but there are differences in the charging and operating
characteristics of the lead-acid battery.

Power Products Guide
Section 2 Batteries
2-9
Figure 2-2 Model 946 Lead-Acid Battery
The lead-acid battery offers higher capacity than the
nickel-cadmium battery at a lower price. However, fewer
charge-discharge cycles are generally possible. If your experience
has been with the nickel-cadmium battery, please study the fol-
lowing before using the lead-acid battery.
•Do not run an instrument to complete discharge
of the battery. Total discharge of gelled-electrolyte
batteries can cause cell reversal, and this can ruin the
battery. One manufacturer recommends 10.5 VDC,
loaded at 400 mA, as complete discharge of a 12-volt
battery.
•Although it may appear that there is still much
power left when the battery voltage drops to 10.5
VDC, in fact, there is very little. Trying to use all
remaining power from a battery will cause cell reversal.
The weakest cell is the first to fail in a battery. The first
cell depleted will be forced into reversal by the rest of
the battery, if the load is still connected.
•Recharge lead-acid batteries as soon as possible
after use. Unlike nickel-cadmium batteries, if you leave
lead-acid batteries partially or fully discharged for any
period of time, they may not recharge to full capacity.
Eventually they will not accept or retain a charge at all.
•Battery life is related to the depth of the
discharge cycle. One manufacturer specifies that you
can expect only 200 cycles at 100% discharge for each
cycle. With a 50% depth of discharge, this number
increases to over 400 cycles. With a 30% depth of
discharge, cycle expectancy increases to over 1,000.
•Avoid the use of lead-acid batteries in subfreezing
environments, especially where you expect deep
discharge. One manufacturer recommends that you
use them above 5oF (–15oC). While a fully-charged
lead-acid battery will withstand cold temperatures, a
discharged battery can freeze if the temperature is low
enough, and that can ruin it. If frozen, the battery could

Power Products Guide
Section 2 Batteries
2-10
swell and crack the case. This will ruin the battery and
could also release toxic substances.
•You can easily damage a gelled-electrolyte
lead-acid battery by overcharging. By necessity, the
amount of water in a gelled-electrolyte battery is quite
limited. The batteries have a one-way safety vent in
each cell that releases water when overcharging causes
the pressure to build up inside the battery. Unlike
wet-cell lead-acid batteries (such as automotive types),
you cannot replace the water. Repeated venting will dry
out the cells and kill the battery. Optimal charging
causes the battery to release no water vapor and very
little gas from the plates.
•Lead-acid batteries are not charged the same way
as a nickel-cadmium battery. Proper charging is done
with a constant voltage and a tapering (or declining)
current.
Chargers for nickel-cadmium batteries typically use a con-
stant-current method. Overcharging is more likely to damage a
lead-acid battery by forcing the vents open and drying it out.
2.3.1 Charging Lead-Acid
Batteries
Isco’s Model 963 Single Station Battery Charger can be used
to charge lead-acid batteries.
In addition, the Isco Model 965 Five-Station Battery
Charger has outputs that can be switched for lead-acid bat-
teries.
Some battery manufacturers recommend charging the lead-acid
battery near room temperature (70° F or 23° C), if possible.
Chargers are typically designed to operate at room temperature.
Temperatures deviating significantly either direction from room
temperature may cause inaccuracies in charging the lead-acid
battery, with potentially harmful long-term effects. The Model
965 Five-Station Battery Charger contains compensation for
charging at higher and lower temperatures, but the other
chargers do not.
When charging lead-acid batteries of any type, please consider
the following:
• Disconnect the battery from the equipment it is
powering before charging.
• Connect the battery to the charger before plugging the
charger in or turning it on; this prevents sparks.
• Never charge the battery in a sealed container, nor in an
unventilated room.
• Do not let the charger run unsupervised or for a long
period of time.
• Do not charge the battery upside down.
• Charging produces explosive gases; do not charge near open
flames or sparks.
• Do not smoke around the battery while it is charging.

Power Products Guide
Section 2 Batteries
2-11
• Do not overcharge the battery.
• Unplug the charger from the AC supply before discon-
necting the battery. This will prevent any sparking that
could ignite the gases produced by charging.
Charge retention is substantially better for lead-acid batteries
than for nickel-cadmium types. While a nickel-cadmium battery
can self-discharge completely in a matter of months, a lead-acid
battery will still have 50% of capacity for nine months to a year
when stored at room temperature (70° F or 23° C). At 100° F (38°
C), the time drops to four months. At 40° F (5° C), the time is over
a year.
However, if a lead-acid battery does self-discharge completely, it
will often be ruined, due to sulfation of the plates. This is very
different from the nickel-cadmium battery, which is not harmed
by remaining in the discharged state, even for considerable
periods of time.
The voltage available from a lead-acid battery drops in a straight
line as the battery discharges. This is due to depletion of sulfate
ion from the electrolyte, raising the internal resistance. Available
voltage drops gradually from approximately 12.5 at full charge to
10.5 at total discharge (under load). Note that it is important to
measure the battery under load. A discharged lead-acid battery
may still show 12.5 VDC, when measured with no load.
Nickel-cadmium batteries show essentially constant voltage
across most of the discharge range.
2.3.2 Using Other Battery
Chargers
Note that an earlier version of the five-station charger is for use
with nickel-cadmium batteries only. It is possible to use
chargers for Isco nickel-cadmium batteries to charge
lead-acid batteries, but it is NOT recommended!
You must be careful to avoid overcharging, since a
nickel-cadmium charger delivers too much current in the latter
stages of charging. Since its open-circuit voltage is high (30
VDC), the current will remain constantly high, no matter what
the charge state of the battery is. If not turned off at the proper
time, the charger will boil the electrolyte. There is a table printed
on the lead-acid battery that tells you how long to charge with a
nickel-cadmium charger.
Because of the risk of damage to the battery from a
nickel-cadmium charger, consider using an accurate digital volt-
meter to monitor the charge voltage. Discontinue charging when
the battery voltage reaches 15.0 VDC. Charging until the
battery “feels warm” is not a reliable indicator for these batteries,
as you may already have overcharged them. Discontinue
charging if you hear a bubbling sound coming from the batteries.
2.4 Model 948 Lead-Acid
Battery
In addition to the Model 946 and 947 Lead-Acid Batteries,
Teledyne Isco offers a much larger battery, the Model 948. This
battery, which resembles an automotive battery, has a capacity of
45 ampere-hours, eight and a half times the capacity of Models
946 and 947.

Power Products Guide
Section 2 Batteries
2-12
Like the Model 946 battery, the Model 948 is a gelled-electrolyte,
maintenance-free battery. This battery is particularly well-suited
to installations that have moderate-to-heavy power require-
ments. It is also suitable for installations that have fairly low
power requirements, but because of their location, must operate
unsupervised for long periods of time.
Figure 2-3 Model 948 Battery
Teledyne Isco offers the battery, a convenient carrying case (rec-
ommended) and a six-foot connect cable. The cable terminates
in a two-pin M/S connector suitable for attachment to Isco sam-
plers and flow meters. The cable is protected with grease where
it connects to the battery.
Teledyne Isco also offers a special battery charger suitable for
recharging the Model 948 Battery (Figure 2-4). We recommend
the use of this charger, as it automatically senses when the
battery is charged and reduces the current to a safe level, thus
avoiding the possibility of overcharge. Most automotive-type
chargers do not have this capability.
This charger has an output of 6 amperes and is supplied with
leads terminated in alligator clips for easy connection to the
battery. To recharge the Model 948, simply remove the top of the
carrying case and connect the red (positive +) clip to the positive
(+) terminal on the battery and the black (negative –) clip to the
negative (–) terminal on the battery. Follow the instructions
printed on the charger. For safe charging refer to the comments
made for the Model 946.
If you want to charge the battery with a different charger, note
the charging conditions indicated on the battery label. The
battery manufacturer recommends that the initial charge not
exceed C/5, which in this instance would be 9 amperes.