Sun Fun Kits SFK-260 User manual

sunfunkits.com
SFK-260/275EX USER MANUAL
REVISION 1.5

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SFK-260/275EX Lithium Iron Phosphate
TABLE OF CONTENTS
INTRODUCTION 02
WEIGHT & DIMENSIONS 05
SAFETY 06
GENERAL USAGE 07
SAFE MODE 09
MAX AMPS & VOLTAGE 09
CHARGING & DISCHARGING 12
LOW TEMP CHARGING 13
MAINTENANCE 15
MULTIBATTERY SETUPS 17
IOS & ANDROID APPS 22
BMS ALERTS 24
MULTIVIEW 35
8 YEAR WARRANTY 41
LEGAL INFORMATION 43
TEST REPORT & QR CODE 46

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SFK-260/275EX Lithium Iron Phosphate
Introduction
THANK YOU
Thank you for purchasing your Sun Fun Kits battery kit system, your battery has been hand built by Sun
Fun Kits technicians in our Baton Rouge (Louisiana, USA) facility using components from China, United
States, and India. We have tested your battery by performing a complete balance, capacity, and load test
to ensure it is built to industry standards. Your battery comes ready to use and we recommend you review
this manual on how to get the optimum performance and longevity of your unit.
We have built the SFK-260/275EX battery to be serviceable and upgradeable, this allows for efficient
service and repairs and ensures product longevity. The nature of kit built products comes with some con-
siderations; they are not as rugged as non serviceable products so care needs to be given when handling
battery kits. However non serviceable products generally have to be disposed of in case of issues (regard-
less of how insignificant) this contributes to e-waste and is against many right to repair laws; because of
this we feel our kit approach offers the best in reliability and longevity for our customers.
Please review this usage manual before using your battery/kit to ensure many years of reliable use. NOTE:
The battery will arrive with approximately 35% SOC (state of charge) and should be charged to 80-100%
before use. This is necessary to comply with shipping regulations; see the charging section for details.
Introduction
OVERVIEW
The SFK-260/275EX is a high performance battery made with EVE, REPT, LISHEN, or CALB certified au-
tomotive grade cells, under optimal conditions it can provide up to 6000 cycles at a depth of discharge of
80% and has an expected life cycle of about 12-15 years. Below we highlight some of the core features of
this unit:

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SFK-260/275EX Lithium Iron Phosphate
Made in the USA with domestic and globally sourced components in our facility in Baton Rouge,
Louisiana.
Made with CERTIFIED AUTOMOTIVE GRADE cells. Every cell in our batteries has its full auto-
motive grade report on its label and this can also be viewed on our website by logging into your
account. Sun Fun Kits batteries DO NOT use reject / failed / grade B cells in their construction as is
the case with practically all batteries coming straight from China and being sold online by retailers.
Upgradable and serviceable, features a tongue & groove construction to allow for sealing the lid to
the body for marine use (can be done with permanent or removable sealant).
USA 8 year warranty including all support, service, and repair in the USA.
Introduction
CONSTRUCTION
3.4-3.6 kilowatt-hours of reliable lithium power, replaces up to 5 lead acid / agm batteries (100ah)
and is designed to be fully utilized 0-100%
2.2 kilowatts of peak power, and 1500 watts of continuous power. Using Amp Boost, max output
increases to 2.4 kilowatts with 200 amp discharge.
Expected cycle life of 6000 cycles at 80% depth of discharge, and up to 7000 cycles at 50% depth
of discharge, 12-15 year usage life.
Introduction
PERFORMANCE

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SFK-260/275EX Lithium Iron Phosphate
Fully compatible with existing 12v infrastructure including standard 12v lead acid/agm battery char-
gers, trickle chargers and high voltage DC systems up to 48v (when in 4s series configuration).
High and low temperature protection including built in heating pads to allow for low temperature
charging.
Automatic low/high voltage cut-off to stop battery damage from occurring.
Automatic short circuit prevention as well as overcharge and over discharge prevention.
Only 57.7 lbs, one of the lightest watt / pound batteries on the market.
The battery can be monitored via bluetooth and has apps for Apple IOS & Google Android; view
the status of charge, the health of your cells, power output, temperature readings and more.
Users can adjust battery parameters such as setting up power output limits, max/min soc, turn the
battery on or off via a software switch and also set up pin code protected access to the battery.
View the combined output of multiple batteries using multi-view; supports up to 4 batteries at the
same time.
Coming Soon: Wireless to inverter communication, send battery information to many inverter
makes & models such as: Victron, Voltronix (MMPT Solar, EG4, PowMR, Growatt, Renogy), Magnum
energy and more.
Introduction
SMART FEATURES

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SFK-260/275EX Lithium Iron Phosphate
Physical Specs
WEIGHT & DIMENSIONS
LENGTH: 14.6” (including handles)
HEIGHT: 10.6” Phys-
ical, terminal studs
will add 1”, total height
combined is 11.6”
WIDTH: 7.5”
Physical Attribute Value Notes
Width 190 MM , 7.5 Inch The width will tapper out 6mm from the bottom to
top.
Length 345 MM , 13.6 Inch 14.6 Inch / 371 MM Including handles
Height 265 MM , 10.65 Inch 11.6”/ 285 MM including terminal bolt
Weight 26 KG, 57.7 Lbs Total weight including terminal bolt, handles &
securing nuts.

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SFK-260/275EX Lithium Iron Phosphate
Before you begin
SAFETY
Sun Fun Kits recommends an experienced electrician setup your battery bank system, or you have exten-
sive knowledge and experience in setting up high power DC systems. Setting up batteries improperly can
result in severe injury and even death. Please take caution when working with our batteries and ensure you
have proper safety equipment and tools, please follow these safety tips:
Wear safety equipment and tools including eye protection, insulating gloves, and use electrically
safe tools.
The use of proper circuit breakers, fuses and DC disconnects is recommended. Please ensure
installs and setups are done by certified electricians, or licensed installers/dealers.
Sun Fun Kits SFK-260/275EX battery contains a battery management system (BMS) that protects
the battery from overcharging, discharging and temperature extremes. Users must ensure their
electrical setup works within these parameters and assume that the BMS protection is secondary
protection ONLY.
Reverse Polarity can cause damage to your battery, ENSURE you have properly set up your electri-
cal wiring.
Battery short-circuits can damage your bms and battery, ensure you are using insulated tools when
installing the battery and that you have planned your install carefully before beginning.

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SFK-260/275EX Lithium Iron Phosphate
Ensure bolts are tightened and installed correctly on all cables and power
disconnections/bridges, loose terminals can cause permanent damage and lead to electrical fires
as it increases resistance in an electrical circuit.
ALWAYS ensure the battery is oriented properly and has the terminals facing up. DO NOT place the
battery upside down or on its sides. This will cause permanent damage to your battery.
Keep away from direct sunlight and water, these battery units are not water sealed in order to make
them serviceable. If you are using them in a situation where they are exposed to the elements, you
must take appropriate measures to ensure they are isolated from these environmental factors.
General Usage
LFP BATTERY
LFP or Lithium Iron Phosphate is one of the safest lithium based chemistries in the market. Unlike other
chemistries such as Li-Ion or Li-polymer these batteries do not have thermal run-away, and will not ignite
or burst into flames (in rare circumstances, if the cell is punctured; the electrolyte is flammable and may
ignite if exposed to an ignition source). It is the only chemistry recommended for recreational use and has
been confirmed to be the safest lithium option by independent labs and government agencies (FAA trans-
portation study https://www.fire.tc.faa.gov/pdf/TC-16-17.pdf).
Sun Fun Kits LifePo4 batteries may be used anywhere typical deep cycle lead acid/agm/flooded batteries
are used and do not require special charging equipment as they have built in circuitry that ensures proper
charging and discharging. It is recommended that you use lithium LifePo4 chargers whenever possible
or set your charging apparatus to the AGM charging profile to ensure that your batteries can get fully
charged.

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SFK-260/275EX Lithium Iron Phosphate
Use in RVs as a 12-48 volt power source, or as part of an inverter bank to provide standby power
Use in solar panel installs as a power source for storing power
Use in troller motor applications for boats (requires ensuring that the battery is isolated and protect-
ed from water intrusion)
Use in Golf Carts or other small electric vehicles that have amperage governors (care must be tak-
en to ensure that the batters are protected from water intrusion)
As a DC power source for power supplies and other items needing DC power
Use in DC to AC inverters where standby / backup power is needed such as data
centers, or residential power sources.
Sun Fun Kits offers the SFK-PS-330 (https://www.sunfunkits.com/product/21/sun-fun-kits-136v-330-
watt-lithium-charger-lifepo4 ) charger that can be used to fully charge your LifePo4 batteries for custom-
ers looking for a stand-alone wall outlet charger.
Here are some acceptable uses for the SFK-260/275EX battery:

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SFK-260/275EX Lithium Iron Phosphate
Usage Restrictions
SAFE MODE
Lithium Iron Phosphate batteries are not recommended for applications that require high amperage
bursts such as starting engines or use in DC arc welding. This will trigger the maximum amp cut-off in the
battery’s built in BMS (battery management system) and will engage a 30 second shut down.
If you exceed the amp limit of your battery or have gone to below 0% SOC and find that the battery is not
outputting power, it may be because the battery has gone into safe mode. Safe mode protects the battery
from damage and requires a cool down period of up to 5 minutes before it can be available for use again.
In order to take out the battery of safe mode, you will need to apply an external power source of 13 volts or
higher to “wake up” the battery, this can be done using any standard 12v charger.
Usage Restrictions
MAX AMPS & VOLTAGE
Sun Fun Kits SFK-260/275EX batteries can be connected in parallel or in series. You can connect up to 4
batteries in series to achieve a maximum voltage of 60 volts (this is generally shown as 48v, the nominal
reading) and you can parallel these batteries up to 4 units. Regardless of how you configure your batteries,
we recommend you keep your combined power output to under 3,000 watts for sustained use with a max
peak of 5 kw (30 seconds) and a maximum continuous amp discharge of 125 amps per battery. You will
also need to ensure that you have selected the proper wire gauge and wire materials to ensure you can
safely deliver your desired power output. A brief chart lists power usage and wire / gauge requirements

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SFK-260/275EX Lithium Iron Phosphate
Guage Volts Amps Power
4 AWG 13.6 75 1,020 watts
4 AWG 27.2 75 2,040 watts
4 AWG 54.4 75 4,080 watts
2 AWG 13.6 125 1,700 watts
2 AWG 27.2 125 3,400 watts
2 AWG 54.4 125 6,800 watts
*For power requirements greater than 4 kw continuous, you will need to have multiple banks of batteries connected to different inverters / dc banks.
Sun Fun kits recommends using the highest possible voltage available in your power system for multi
battery setups, and limiting the total output to below 125 amps, we also recommend using 2 Awg or lower
pure copper wire.
Charging & Discharging
BATTERY SPECS
Lithium Iron Phosphate batteries do not require special charging equipment as they have built in circuitry
that ensures proper charging and discharging. This means you can use “any standard 12v based battery
charger”. We do recommend you use lithium LifePo4 chargers whenever possible, or set your charging
apparatus to the AGM charging profile to ensure a good charge. Sun Fun Kits offers the SFK-PS-330
(https://www.sunfunkits.com/product/21/sun-fun-kits-136v-330-watt-lithium-charger-lifepo4 ) charger
that can be used to fully charge your LifePo4 batteries for customers looking for a stand-alone wall outlet
charger. NOTE: For smart lead acid chargers, you may need to force bulk/absorption mode to ensure a

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SFK-260/275EX Lithium Iron Phosphate
a full charge. The charging and discharging parameters for the SFK-260/275EX are listed below:
Parameter Value Notes
Low voltage cut-off 10.0-11.6 volts / 2.5 - 2.9
volts (cell)
Battery will go into Safe Mode at this voltage.
Full Charge 14.6 volts / 3.65 volts (cell) Maximum charge voltage.
Nominal Voltage 13.0 Volts / 3.25 volts (cell)
12.8 Volts / 3.2 volts (cell)
Nominal voltrage range is between 12.8-13.2 volts.
BMS Self Discharge 0.052 amps / day A fully charged battery will discharge to low SOC in
about 500 days
BMS Balance 5 amp active balancer. Balancing will happen between 2.9v-3.65v ONLY.
Recommended Dis-
charge
800 watts Discharge rates of 800 watts and below will yield
the longest battery life.
Max Continuous Dis-
charge
1500 watts This is the highest suggested discharge for an
extended period of use (over 1 hour).
Peak Discharge 2.2 kw (120 seconds) Must not exceed 200 amps.
Recommended
Charge Rate
330 watts (23 amps) Slower charging will result in a complete charge
and also extend battery life.
Max Charge Rate 1250 watts (110 amps) //
Surcharge Disconnect 160 amps The battery will stop charging if it detects a surge
of more than 170 amps.
Recommended Usage
Temp.
70° Fahrenheit Batteries are happiest in the same temperature
range we like to be.

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SFK-260/275EX Lithium Iron Phosphate
Parameter Value Notes
Minimum Discharge
Temp.
34° Fahrenheit Battery will go into Safe Mode at this temperature.
Maximum Charge
Temp.
130° Fahrenheit //
Minimum Charge
Temp.
34° Fahrenheit //
Short Circuit Protec-
tion
210 amps The BMS will turn the battery off if more than 210
amps are drawn from the battery.
Usable Battery Capac-
ity
260 AH / 275 AH This is regulated by the BMS to ensure battery
integrity.
Cell Capacity (AH) 272 - 285 | 285 - 295 This is the actual cell capacity of the individual cells.
Charging & Discharging
MAINTENANCE
Sun Fun Kits Lithium Iron Phosphate batteries require minimal maintenance and do not need to have any
liquid added to them such as water (as is the case with flooded lead acid) in order to keep charge. The
only maintenance required is to ensure that the state of charge of the battery is in a reasonable state de-
pending on how it is being used. Please see the chart below:
State of Charge Recommended Use Notes
80-100% Normal Use For normal everyday use, keep your battery in this
range if you are using it at least once a month.
50% Long term storage Keep your battery in this state when you will not be
using it (for more than a month).
25-35% Transport For use in transport / maintenance, when your
battery is shipped to you, or if you need to return it,
it should be in this SOC.

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SFK-260/275EX Lithium Iron Phosphate
State of Charge Recommended Use Notes
15% or lower Low charge! Charge bat-
tery ASAP.
This is a low SOC, do not keep your battery in this
state for a long period of time or it will cause per-
manent damage to it.
Charging & Discharging
LOW TEMP CHARGING
The SFK-260/275EX is equipped with internal heating elements (silicone rubber heater pads) that are
designed to turn on and warm up the battery during cold environments while the battery is being charged.
The settings for this are available in the tools tab within the official Sun Fun Kits management app can be
configured to be turned on at 35, 40, 45, or 50 degrees Fahrenheit. In cold temperatures, charging will
be dissabled and any voltage input to the battery will be sent to the heating elements to raise the internal
temperature until it is at least 5 degrees above the setting specified in the tools tab. E.G. If the setting is set
to 40 degrees, then the battery will continue to warm up until the internal temperature is at least 45 de-
grees at which point normal charging will resume. We recommend keeping maximum charging to under
30 amps in temperatures below 50 degrees.
NOTE: The heating mechanism will not turn on during discharging, or when the battery is in standby. If you
would like to maintain the internal temperature of your battery, the 260EX (available as an option on the
275EX) is equipped with a manual 5 mode heating switch that will allow you to maintain an internal battery
temperature between 65 - 95 degrees Fahrenheit.

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SFK-260/275EX Lithium Iron Phosphate
Manual Heat Switch: To engage the manu-
al heat switch, press and hold the button for 2
seconds, this will turn on the unit and will set it
to mode 1, the ECO mode. Mode 1 will use the
heating pads to reach an internal temperature of
about 65°- 75°, mode 2 between 76°- 85°, mode
3 between 86°- 95°and modes 4 and 5 are timer
modes which will maintain about 75° for 12 and
24 hours respectively. It is recommended to turn
off the manual switch when you don’t need it,
simply press and hold it for 2 seconds to turn
off the manual heating. Once off, the standard
failsafe low temperature charging heating of the
BMS will work as normal..
1ECO Mode
2Medium Mode
3High Mode
412 Hour Mode
524 Hour Mode

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SFK-260/275EX Lithium Iron Phosphate
Wiring & Setup
MAINTENANCE
It is recommended to periodically inspect your wiring schematic and ensure all bolts and terminals are
properly installed and tight. Depending on the discharge/charge rate you may experience loosening of
terminals due to thermal expansion. If this occurs you will need to re-tighten your bolts.
The main terminal bolts on the SFK-260/275EX are under the battery case, to access this you will need
to remove the 4 top M4 countersunk screws. Once the case is removed, you can use a M8 ball-end hex
driver or L-wrench to ensure that they are snug and making proper contact with the brass conductor ring.
If they are loose, you will need to tighten them. NOTE: loose bolts will cause the battery terminals to heat
up as they become a source of resistance, this must be addressed or it will cause permanent damage to
your battery and can lead to a fire hazard.
You should also check that the battery is kept away from water & moisture and that there is proper ventila-
tion to maintain temperature & humidity. These issues can lead to battery performance and degradation if
not resolved; they may not be apparent immediately, but will have a cumulative effect in the long term.
There are 4 countersunk M4-15mm
Screws that hold the top lid in place.
In order to access the inside of the
battery, you will need to unscrew
them with an appropriate allen key.

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SFK-260/275EX Lithium Iron Phosphate
We only recommend opening the lid
of your battery with hand tools and
not with powered screwdrivers or
impact drivers.
Ensure the wires are tight and make
good contact with components, tight-
en if needed.
Only use insulated tools when work-
ing with the battery with its lid open.

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SFK-260/275EX Lithium Iron Phosphate
Wiring & Setup
MULTI-BATTERY SETUPS
The SFK-260/275EX offers various multi-battery setups, these allow you to increase your total available
amperage as well as voltage. The flexibility of this allows batteries to be used in 12v, 24v, 36v, as well as 48v
setups. We will detail these options below.
NOTE: for many parallel setups we recommend the use of a common DC bus bar with equal wire lengths
to ensure proper load splitting. The Sun Fun Kits DC Bus Bar works great for most parallel setups: https://
www.sunfunkits.com/product/35/heavy-duty-bus-bars-250a-600v . We always recommend you consult
an electrician before proceeding to ensure your loads are adequately spread among your batteries.
The SFK-260/275EX should only be used with batteries of the same type. You should avoid mixing and
matching the: SFK-260, SFK-260EX, SFK-260HP, SFK-275HP, or SFK-275EX batteries or batteries of
other brands in the same bank. Doing so may overload or cause unequal loads in your bank. Regardless
of which setup you decide to use, the total number of batteries in a bank should not exceed 4/bank. If you
need more than 4 batteries, you should consider making another bank and then connecting them with
appropriate load balancers.

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SFK-260/275EX Lithium Iron Phosphate
Wiring & Setup
PARALLEL OPERATION
The most common parallel setup is the 2P setup, where two batteries are connected in parallel thereby in-
creasing battery capacity to 520 / 550 AH while keeping the voltage at 12.8 - 13.0 volts. These setups can
be used with piggyback cables, or can be set up using DC bus bars.
In all parallel setups, you must ensure
your cables are of equal length, we
recommend using 2 AWG or lower
gauge for best performance.
For optimal performance, consider
the use of dedicated bus bars.

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SFK-260/275EX Lithium Iron Phosphate
For even greater capacity, the SFK-260/275EX can be wired in 3P and 4P configurations, this will increase
overall battery capacity to 780 / 825 AH and 1040 / 1100AH respectively. NOTE: DEDICATED BUS BARS
ARE REQUIRED FOR 3P AND 4P SETUPS. Sun Fun Kits does not support more than 4P connections
due to the very high amp loads it can generate.