12V 20Ah
Deep Cycle Lithium Battery


12V 20Ah
Deep Cycle Lithium Battery

The RB20 lithium iron phosphate battery provides ample power for high amp draw electronics or in outdoor recreational use where lighter weight and capacity are key. It's commonly used in fishing electronics, robotics, solar lighting, remote power and other deep cycle applications.



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Maintenance Free

Plug, play, and charge. No watering, no corrosion.

Lightweight & Easy to Transport

Compared to other battery chemistries, RELiON LiFePO4 batteries provide the same or greater energy at less than half the weight and size. This means more flexibility and ease of use!

Long Life

RELiON lithium batteries provide up to 10 times longer life than lead-acid batteries, and they still provide 80% of the rated capacity after 3,500 cycles.

Fast Charging

RELiON lithium batteries charge much faster than traditional lead-acid batteries, and they’re packed with more usable energy so you’re always ready to go!

Partial State of Charge Tolerant

Partial charging does not affect performance quality or battery life. A low self-discharge rate means worry-free storage so even occasional users can be assured of reliable performance.

Constant Power

Full power available throughout discharge. Voltage does not drop like lead-acid.

Eco-Friendly & Safe

RELiON lithium batteries are the ultimate clean energy. No gassing, no fumes, and no pollution. Enjoy reliable power, while protecting the environment, using these non-hazardous batteries.



Electrical Specifications

Nominal Voltage 12.8 V
Nominal Capacity 20 Ah
Energy 256 Wh
Resistance ≤60 mΩ @ 50% SOC
Efficiency 99%
Self Discharge <3% per Month
Maximum Batteries Connected in Series 3

Mechanical Specifications

Dimensions (L x W x H) 7.1 x 3.0 x 6.7” (181 x 76 x 169 mm)
Weight 5.6 lbs (2.55 kg)
Terminal Type M6 x 1.0
Terminal Torque 35 - 44 in-lbs (4 - 5 N-m)
Case Material ABS
Enclosure Protection IP66
Cell Type - Chemistry Cylindrical - LiFePO4

Discharge Specifications

Maximum Continuous Discharge Current 20 A
Peak Discharge Current 40 A (7.5 s ±2.5 s)
Discharge Over-Current Protection 70 A ±10 A (20 ±5 ms)
Recommended Low Voltage Disconnect 11.0 V
Discharge Under-Voltage Protection 8.0 V (2.0 ±0.08 vpc) (140 ±60 ms)
Reconnect Voltage 10.0 V (2.5 ±0.10 vpc)
Short Circuit Protection Response Time 200-500 µs

Charge Specifications

Recommended Charge Current 1 A - 10 A
Maximum Continuous Charge Current 20 A
Charge Current 32ºF to 14ºF (0 to -10 ºC) ≤0.1 C (2 A)
Charge Current -4ºF to 14ºF (-20 to -10 ºC) ≤0.05 C (1 A)
Recommended Charge Voltage 14.2 V - 14.6 V
BMS Charge Voltage Cut-Off 15.2 V (3.8 ±0.025 vpc)
(1.1 ±0.4 s)
Reconnect Voltage 14.4 V (3.6 ±0.025 vpc)
Balancing Voltage 14.4 V (3.6 ±0.025 vpc)

Temperature Specifications

Discharge Temperature -4 to 140 ºF (-20 to 60 ºC)
Charge Temperature* -4 to 113 ºF (-20 to 45 ºC)
Recommended Storage Temperature 23 to 95 ºF (-5 to 35 ºC)
BMS High Temperature Cut-Off 158 ºF (70 ºC)
Reconnect Temperature 122 ºF (50 ºC)
*Refer to charge currents below 0°C (32°F)

Compliance Specifications

Certifications UKCA & CE (battery)
UN38.3 (battery)
UL1642 (cells) (File# MH64523)
IEC62133 (cells)
Shipping Classification UN 3480, CLASS 9

Performance Characteristics

Charge Voltage Char Chart 12 V graph
Charge Voltage Soc Chart 12 V graph
Discharge Voltage At Various Rates 12 V graph
Discharge Voltage Chart 12 V graph
Life Vs Lead Acid Chart graph
Cycle Life Vs Depth Discharge Chart graph


Brian Evans

I have had this 20 ah battery for about 4months and it's doing a very good job for a small battery it runs a 15 QT 12volt compressor frig for about 12 hrs and I'm very impressed with it so far

Brian Evans

Aug 2nd, 2020

I have had this 20 ah battery for about 4months and it's doing a very good job for a small battery it runs a 15 QT 12volt compressor frig for about 12 hrs and I'm very impressed with it so far.

The RB20 Is Great For Powering

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Renewable Energy

Understanding Battery Terms

Understanding the basics of battery ratings and terminology is important when comparing and selecting the right type and number of batteries for your application to ensure you have enough energy to meet your energy goals.

Learn More About Battery Terms

We're Invested In Our Lithium Iron Phosphate Batteries

Lithium Certifications Recycling 1000X300