sunfun SFK-275HP User manual

sunfunkits.com
REVISION 1.2
SFK-275HP USER MANUAL

SFK-275HP Lithium Iron Phosphate
01
TABLE OF CONTENTS
INTRODUCTION ...................................................... 1
SAFETY ......................................................................... 2
LFP BATTERY ............................................................ 4
SAFE MODE ............................................................... 5
MAX AMPS & VOLTS ............................................. 5
BATTERY SPECS ..................................................... 6
MAINTENANCE ........................................................ 7
WEIGHT & DIMENSIONS .................................... 11
IOS & ANDROID APPS ..........................................12
8 YEAR WARRANTY .............................................. 13
LEGAL INFORMATION ..........................................15

Introduction:
THANK YOU
SFK-275HP Lithium Iron Phosphate
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 brief guide on how to get the optimum performance and longevity of your unit.
We have built the SFK-275HP 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 consider-
ations; they are not as rugged as non serviceable products so care needs to be given when handling bat-
tery kits. However non serviceable products generally have to be disposed of in case of issues (regardless
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 at 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.
02
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:

SFK-275HP Lithium Iron Phosphate
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-275HP battery contains a battery management system (BMS) that protects the
battery from overcharging, discharging and temperature extremes. Users must ensure their electri-
cal setup works within these parameters and assume that the BMS protection is secondary protec-
tion 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.
Ensure bolts are tightened and installed correctly on all cables and power
disconnections/bridges, loose terminals can cause permanent damage as well as 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.
03

General Usage:
LFP BATTERY
SFK-275HP Lithium Iron Phosphate
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 overcharged / over discharged. 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
transportation 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 batter-
ies 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. 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. Acceptable uses are:
04
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)

SFK-275HP Lithium Iron Phosphate
05
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.
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
batteries built in BMS (battery management system) to stop sending current and the system will engage in
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-275HP batteries can be connected in parallel or in series. You can connect up to
4 batteries in series to achieve a maximum voltage of 58 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 4,000

SFK-275HP Lithium Iron Phosphate
06
watts for sustained use with a max peak of 6.8 kw (30 seconds) and a maximum amp discharge of 125
amps. 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 below:
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 on your power system, 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

SFK-275HP Lithium Iron Phosphate
07
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 full
charge. The charging and discharging parameters for the SFK-275HP are listed below:
Parameter Value Notes
Low voltage cut-off 10.6 volts / 2.65 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 13.6 Volts / 3.4 volts Nominal voltrage range is between 13.2-13.6 volts.
BMS Self Discharge 0.52 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
700 watts Discharge rates of 700 watts and below will yield
the longest battery life.
Max Continuous Dis-
charge
1250 watts This is the highest suggested discharge for an
extended period of use.
Peak Discharge 1.8 kw (30 seconds) Must not exceed 150 amps.
Recommended
Charge Rate
330 watts (23 amps) Slower charging will result in a complete charge
and also extend battery life.
Max Charge Rate 900 watts (80 amps) //
Surcharge Disconnect 83 amps The battery will stop charging if it detects a surge
of more than 83 amps.
Recommended Usage
Temp.
70° Fahrenheit Batteries are happiest in the same temperature
range we like to be.
Maximum Discharge
Temp.
120° Fahrenheit Battery will go into Safe Mode at this temperature.

SFK-275HP Lithium Iron Phosphate
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Parameter Value Notes
Minimum Discharge
Temp.
34° Fahrenheit Battery will go into Safe Mode at this temperature.
Maximum Charge
Temp.
120° Fahrenheit //
Minimum Charge
Temp.
34° Fahrenheit //
Short Circuit Protec-
tion
155 amps The BMS will turn the battery off if more than 155
amps are drawn from the battery.
Usable Battery Capac-
ity
275 AH This is regulated by the BMS to ensure battery
integrity.
Total Cell Capacity 285-290 ah 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 (in the case of 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 depend-
ing 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.

SFK-275HP Lithium Iron Phosphate
09
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.
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-275HP 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 check that they are snug and are making proper contact with the copper 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.

SFK-275HP Lithium Iron Phosphate
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We only recommend opening the lid
of your battery with hand tools and
not with powered screwdrivers or
impact drivers.
Once this lid is removed you can
investigate the bolts to ensure a tight
slop free fit.

SFK-275HP Lithium Iron Phosphate
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Physical Specs:
WEIGHT & DIMENSIONS
LENGTH: 14.6” (including handles)
HEIGHT: 9.6” Physical,
terminal studs will add
1”, total height com-
bined is 10.6”
WIDTH: 7.5” Physical,
terminal studs will add
1”, total height com-
bined is 10.6”
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 245 MM , 9.65 Inch 10.6”/ 280 MM including terminal bolt
Weight 24.5 KG, 54 Lbs Total weight including terminal bolt, handles &
securing nuts.

SFK-275HP Lithium Iron Phosphate
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Management Apps:
IOS & ANDROID
To manage your SFK-275HP, Sun Fun Kits has created easy to use management apps. These are available
for Google Play Store and Apple IOS devices. In order to use these apps you must have a device that is
compatible with the BLE Bluetooth protocol.
Google Play Store Link:
https://play.google.com/store/apps/details?id=com.companyname.sfkble&hl=en_US&gl=US
Apple IOS App Store Link:
https://apps.apple.com/ua/app/sun-fun-kits-bms/id1600445506
These apps are available at no charge and can work with all Sun Fun Kits products. Please review the Sun
Fun Kits BMS manual for more details on how to connect and manage your device. Be sure to check back
regularly as the app is updated frequently.

SFK-275HP Warranty:
8 YEAR WARRANTY
SFK-275HP Lithium Iron Phosphate
Sun Fun Kits guarantees purchases made from its website or authorized retailers are free from manu-
facturer defects and will repair or replace battery and kits that fail to meet specifications at our discretion
within the warranty period. Warranty is only offered to the original purchaser and will require a warranty
transfer to any user that the battery has been sold to thereafter by the end user (limited to a maximum of 1
transfer). Warranty details are explained below:
SFK-275HP 8 Year 60/96 Warranty
The SFK-275HP 8 Year 60/96 warranty provides free repair/replacement of items for the first 60 months,
and a prorated repair/replacement for the remaining 36 months. This warranty also guarantees a full 100%
cycle life for the first 500 cycles, between 100-90% for the next 500 cycles, and between 90-80% life for
the next 500 cycles. After approximately 1500-2000 cycles, customers can expect between 80-70% of
the original rated capacity.
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SFK-275HP Warranty:
EXCLUSIONS
Improper Installs
Damage resulting from improper installs are not covered under warranty, this includes (but is not limited
to) short circuits, reversed polarity damage, not placing the battery upright, excessive moisture, tempera-
tures that exceed OEM thresholds, improperly installed terminal cables, poor ventilation, and excessive
vibration.
Modifications to electronic components
Customer agrees not to perform modifications to battery cells, bms components, case mounting, or any

SFK-275HP Lithium Iron Phosphate
other change that alters the OEM specifications. Doing so will void the warranty.
Changing BMS parameters with unauthorized tools
Customer agrees to only use official Sun Fun Kits software tools made for IOS / Android / Windows to
manage battery systems, the use of unauthorized software tools will void the warranty.
Using battery in non-approved applications
Customer agrees not to use battery & components in automotive operations such as using it as an engine
starting power source (CCA applications), high power applications that exceed 5000 watts total output,
subjecting battery & components to unreasonable tests that do not represent real-world scenarios (e.g.
putting battery in a cold freezer or oven), using the battery as a power source for DC arc welding. These
and other non approved scenarios will void the warranty.
Physical damage and neglect
Customer agrees any physical damage to the battery systems and components (such as dropping the
battery, impaling the battery, submerging the battery in liquid) will result in voiding the warranty. Customer
furthermore agrees subjecting the battery systems and components to environmental factors that exceed
OEM thresholds (exceeding rated temperature limits, charge/discharge watt limits) will result in voiding the
warranty.
Failure to maintain battery
Customer agrees to perform proper maintenance on the battery. This includes ensuring cycling the bat-
tery at least once every 4 months when not in use and ensuring the battery has a 50% or greater charge
when kept in storage. Keeping the battery at less than 15% charge for an extended period of time will
damage the battery and will void the warranty. Battery and kits must not be exposed to temperatures
greater than 110° fahrenheit or lower than 20° for an extended period (greater than 4 hours) NOTE: Sun
Fun Kits BMS system keeps an internal log and Sun Fun Kits technicians can determine if proper
14

SFK-275HP Lithium Iron Phosphate
proper maintenance was not done.
15
Terms, Liabilities & Disputes:
LEGAL INFORMATION
Sun Fun Kits LLC DBA Sun Fun Kits offers its products with the terms, conditions and notices as follows:
The following terms and conditions apply to all sales and uses. Please review carefully. These terms and
conditions include limited warranties and disclaimers of liabilities. Keeping, using or allowing use of Sun
Fun Kits products indicates your agreement to these terms. By checking “Agree” on our website at check-
out also constitutes your agreement to these terms.
Terms of use
This product is offered to you conditioned upon your acceptance without modification of the terms, con-
ditions, and notices contained herein.
Use limitation
You may not modify, copy, distribute, transmit, display, perform, reproduce, publish, license, create deriv-
ative works from, transfer, or sell, any information, software, products or services obtained, from Sun Fun
Kits’ website or its products.
Level of Risk
Lithium batteries, Inverters, high powered DC/AC devices, and apparatus sold by Sun Fun Kits can be as-
sociated with a high level of risk and may pose risk of serious physical injury, burns, disability and/or death.
Users of our products choose to do so at their own risk.
Assumption of Risk
By buying, using, or allowing the use of Sun Fun Kits’ products, you understand and agree that the nature

SFK-275HP Lithium Iron Phosphate
16
of high powered devices can be associated with a high level of risk and, to the extent permitted by law,
YOU EXPRESSLY AND VOLUNTARILY ASSUME THE RISK OF DEATH OR OTHER PERSONAL INJURY
SUSTAINED WHILE USING OUR PRODUCTS, WHETHER OR NOT CAUSED BY THE NEGLIGENCE OR
OTHER FAULT OF Sun Fun Kits, including but not limited to equipment malfunction from whatever cause,
or any other fault of Sun Fun Kits. Additionally, you agree to indemnify, defend, and hold Sun Fun Kits
harmless from any third party claims arising from such High Risk Uses, or any use or misuse of our prod-
ucts.
Limitation Of Liability
As set forth above under the limited warranty provisions, Sun Fun Kits’ liability is limited to repair or re-
placement of its products which are returned to it in the specified period of time. In no event shall Sun Fun
Kits; liability exceed the value of the product(s) sold. In no event shall Sun Fun Kits’ be liable for any direct,
indirect, punitive, incidental, special or consequential damages whatsoever arising out of or connected
with the use or misuse of any of its products.
Warning
Use and misuse of products sold by Sun Fun Kits involves serious risks including injury, disability and
death. Purchasers assume all risks. Inspect before each use. This product must be inspected for use to
ensure it has not been damaged in shipment. If damaged, do not use and immediately return the product
to Sun Fun Kits for a replacement.
Entire Obligation
The PRODUCT LIABILITY DISCLAIMER document states the entire obligation of Sun Fun Kits with respect
to the products. If any part of this disclaimer is determined to be void, invalid, unenforceable or illegal, in-
cluding, but not limited to the warranty disclaimers and liability disclaimers and liability limitations set forth
above, then the invalid or unenforceable provision will be deemed superseded by a valid, enforceable pro-
vision that most closely matches the intent of the original provision and the remainder of the agreement

SFK-275HP Lithium Iron Phosphate
17
shall remain in full force and effect.
Any and all disputes or claims relating in any way while using your Sun Fun Kits products or services will
be resolved by arbitration rather than in court by the American Arbitration Association (AAA). Either party
Sun Fun Kits or the customer may initiate the claim. Claims may also be asserted in East Baton Rouge
Parish Small Claims court if the claim is within small claims court limits.
Arbitration awards are limited, however, an arbitrator can award on an individual basis the same damages
and relief as court (including injunctive and declaratory relief or statutory damages). To request arbitra-
tion you will need to submit in writing via certified mail to: Arbitration Request - Sun Fun Kits 11636
Industriplex Blvd, Baton Rouge, LA 70809.
You will need to accompany your request with a demand letter detailing your complaint. You will then need
to contact the AAA by visiting www.adr.org and file the initiation fee. Sun Fun Kits will reimburse these fees
to you if the arbitrator(s) finds in your favor, however, if the arbitrator(s) finds in Sun Fun Kits favor then no
fees will be reimbursed. Both parties agree that they will be responsible for their own attorney fees regard-
less of the decision by the arbitration process. All ongoing arbitration fees will be split between the cus-
tomer and Sun Fun Kits evenly (50% by each party) after the initial filing fee to start arbitration.
The venue of arbitration proceedings shall be within East Baton Rouge Parish; you may also request to
have arbitration done via phone conferences or via web/video meeting online. East Baton Rouge Parish
Small Claims court awards are limited to $5,000.00 and do not require an attorney, however, you will be re-
quired to file your claim as well as present your case in person for a resolution. If you wish to proceed with
a small claims court claim you may contact the East Baton Rouge Parish Small Claims Court by visiting:
Terms, Liabilities & Disputes:
APPLICABLE LAW

SFK-275HP Lithium Iron Phosphate
18
https://www.brla.gov/319/Civil-Suit-Interactive-Forms
Sun Fun Kits reserves the right to change the terms, conditions, and notices under which it’s products are
offered at any time.
Terms, Liabilities & Disputes:
MODIFICATIONS TO TERMS

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Sun Fun Kits LLC
11636 Industriplex Blvd
Baton Rouge, Louisiana, 70809
United States of America
1-225-289-6525
www.sunfunkits.com
[e-mail]
FCC ID: QDS-BRCM1078