12V 100Ah
Deep Cycle Lithium Starting Battery
Group 31


12V 100Ah
Deep Cycle Lithium Starting Battery
Group 31

The RB100-HP is a lithium iron phosphate battery, built for starting and cycling marine and RV applications. The RB100-HP has increased peak amps for starting motors, electric start generators, and other high-amp-draw devices – plus, it doubles as a house battery, powering peripherals, accessories, and more.


United States Of America White 230216 103954


Warranty White 230216 103954


Free Delivery White 230216 103955



The RB100-HP now includes six battery terminals versus the two on standard batteries, offering users more flexibility when connecting electronics to the battery. The battery includes an IP67 ingress protection rating, which completely repels dust and resists water ingress for up to 30 minutes submerged at 1 meter. Other improvements include an atmospheric vent added to the top of the case that equalizes pressure while preventing contaminants from entering the battery; a glue channel to ensure IP67 seal; screw latched closure to ensure seal longevity, and tied a rope with handle guides that replace ultrasonically welded straps to improve durability.

The RB100-HP is the first battery to be evaluated and approved for use with select Mercury Marine® outboard engines.

Temperature Tolerant

Lithium batteries can handle a wide variety of conditions and are even 2.5x more efficient at low temperatures than lead-acid while being able to safely operate up to 149°F (65°C).

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.


RELiON lithium batteries provide more power than lead-acid batteries and are typically half the weight. Boosting both performance and agility on the water.

Constant Power

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

Maintenance Free

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

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.

More Usable Capacity

Lead-acid batteries are typically sized up to two times your energy needs to account for extended periods without sun and less usable energy with higher rates of discharge. Plus, you are typically cautioned to limit your use to 50% of the rated capacity, as using more can significantly reduce performance. Lithium batteries provide 100% of their rated capacity, regardless of the rate of discharge. And, you can use it all and still get a substantially longer cycle life.

Partial State of Charge Tolerant

Partial state of charge, known as PSOC, which is a killer of lead-acid batteries, does not affect the performance or battery life of a lithium battery. Sometimes batteries don’t get fully charged, or they regularly operate in a partial state of charge. Either way, you can count on RELiON lithium batteries to live a long and productive life.



Electrical Specifications

Nominal Voltage 12.8 V
Nominal Capacity 100 Ah
Reserve Capacity @ 25 A 240 min
Energy 1280 Wh
Resistance ≤30 mΩ @ 50% SOC
Efficiency 99%
Self Discharge <3% per Month
Maximum Batteries Connected in Series 1 (Single Battery Only)

Discharge Specifications

Maximum Continuous Discharge Current 100 Amps
Recommended Maximum Discharge Current 800 Amps
Lithium Marine Cranking Amp (MCA) Rating Up to 800 Amps for 8 seconds @ 20ºF (-6.7ºC)
Discharge Over-Current Protection 1000 A ±100 A (2.2 ±1 ms)
Recommended Low Voltage Disconnect 11.0 V
Discharge Under-Voltage Protection 9.2 V (2.3 ±0.08 vpc) (4.2 ±0.5 s)
Reconnect Voltage 10.0 V (2.5 ±0.1 vpc)
Short Circuit Protection Response Time 200-600 µs

Charge Specifications

Maximum Continuous Charge Current 5 Amps - 50 Amps
Maximum Battery Charger Output 100 Amps
Peak Charge Acceptance Rate 165 Amps for up to 1 minute
Maximum Engine Alternator Size 150 Amps
Maximum Charge Current 14°F to 32°F (-10°C to 0°C) ≤0.1 C (10 Amps)
Maximum Charge Current -4°F to 14°F (-20 to -10°C) ≤0.05 C (5 Amps)
Recommended Charge Voltage 14.4 V - 14.8 V
BMS Charge Voltage Cut-Off 15.4 V (3.85 ±0.025 vpc)
Reconnect Voltage 14.6 V (3.65 ±0.05 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 130 ºF (-20 to 55 ºC)
Recommended Storage Temperature 23 to 95 ºF (-5 to 35 ºC)
BMS High Temperature Cut-Off 176 ºF (80 ºC)
Reconnect Temperature 122 ºF (50 ºC)
*Refer to charge currents below 32°F (0°C)

Mechanical Specifications

Dimensions (L x W x H) 13.0 x 6.8 x 8.8” (329 x 172 x 223 mm)
Weight 29.8 lbs (13.5 kg)
Terminal Type M8 x 1.25 x 12 mm
Terminal Torque 80 - 100 in-lbs (9 - 11 N-m)
Case Material ABS
Enclosure Protection IP67
Cell Type - Chemistry Cylindrical - LiFePO4

Compliance Specifications

Certifications UN38.3, CE & UKCA (battery)
UL1642 (cells) (File# MH62098)
IEC62133 (cells)
Shipping Classification UN 3480, CLASS 9


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


Thomas Shultz

So far it works fantastic. Love the 6-post system. Perfect size for my boat.

Michael B.

This battery is fantastic! It solved all of my power needs for my bass boat. Between multiple sonar units and PowerPoles, the cranking battery just could not keep up. This battery cranks the motor with no effort, even after a full day of fishing. It charges super fast and is as reliable as they come. Very happy with my purchase.

Larry C.

I have been using this battery for almost 2 years with no problems. My boat has a 12" Solix at bow and 12"solix at helm plus 360 imaging and live-wells on this battery. It is also the cranking battery for a Merc 250 8 cylinder. I fish weekly tournaments and have never had it fail to start the engine. I also use 3 Relion 100ah batteries for the trolling motor. Expensive, but in the long run well worth it. When I was using AGM batteries I had to replace them every 2 or 3 years.

Brad G.

I have been out on the water with it 4 times so far. It has worked perfectly. I trolled all day long running both large graphs, playing radio and running live well pump. After about 9 hours a started my main motor and it turned it over effortlessly. Love it! Also took 2 group 31 batteries out of my boat reducing over 100 pounds!

Brian W.

The 36 volt set up with the RB-100 keeps my trolling motor running at peak performance from daylight till dark without any loss in power. The RB100-HP as my main cranking battery that powers all of the electronics (3 including power hungry live scope) live wells, talon shallow water anchors, lights, trim ect. has performed beyond expectation. At the end of a tournament day with everything running I still have 13.2 volts. The recovery time for charging is lighting fast and the huge weight difference switching from heavy AGM's has increase the fuel economy with my outboard and overall performance of my boat. Glad I made the switch to Relion!

Rusty L.

Very impressed with the power this battery has to run all the electronics and still maintain enough amps to crank the motor. Worked with Brad Green and he went the extra mile to get me a battery in such a short amount of time before the tournament. Customer Service like this will make me always come back to RELiON for my next purchase.

Jim T.

I never send in reviews but I have to in regards to this purchase. These batteries have exceeded my expectations. I'm a bass fisherman and need a power supply I can depend so all I have to think about is fishing. These batteries maintain a high output which means my 3 sonar units never go down. 360 transducer never gets distorted which it did with lead acid as the power drained down below the threshold. My trolling motor acts like it picked up 5 lbs of thrust. It is strong all day. I can run my live wells, aerator, oxygenator etc without a concern ill have enough power. My only regret is I should have switched over sooner! Thank you!

Les Sage

I have a Lance truck camper with a built in Cummins Onan Generator. The RB-100HP is the perfect Lithium battery for my application. Since this battery has a very high peak output, it will easily start my generator without any issues. I researched most of the Lithium batteries and nobody else had something comparable in a 100ah batttery (6/20). I am very pleased with the quality and performance! Great company to work with for technical help.

Larry Fadaol

I looked at many different lithium batteries, deciding on Relion. Purchased one of these for my Yamaha 250 SHO and works great! The weight of these batteries are amazing, making it so easy to install. The number one reason for going with this brand was the help and excellent customer service from Brad. He offers good advice on type battery needed and always willing to follow up when there is a question.

Frequently Asked Questions

What specifications do lithium-ion batteries need to meet to be approved for use with Mercury Marine® outboards?
Mercury Marine® recently released a bulletin regarding the use of lithium-ion batteries for starting engines. To ensure boaters achieve optimal performance from Mercury Marine outboards, they now allow the use of lithium-ion starting batteries for an approved list of outboard models. In addition, any lithium-ion battery being used must meet these certain specifications: Chemistry: Lithium Iron Phosphate (LifeP04) is designed for marine cranking use. | Minimum Cranking Amps: 800 Amps for 8 seconds minimum at 20 °F (-7 °C) | Peak Charge Acceptance: 165 Amps I 20–130 °F (-7–55 °C) | Max Charge/Alternator Size: 150 Amps I 20–130 °F (-7–55 °C) | Max Charge Voltage/ Alternator Output: 14.8 V | Reserve Capacity: ([email protected] 80 °F) 135 minutes | Ingress Protection (IP) Rating: IP67 or greater
Has the RB100-HP battery been approved for use with Mercury Marine® outboards?
Yes! RELiON’s RB100-HP lithium battery has been evaluated and it meets all the requirements for use as a starting battery with approved Mercury Marine outboards!
Which Mercury Marine® outboard models are approved for use with the RB100-HP?
Models Covered: 2.1L 75‑115hp FourStroke, Pro XS® and SeaPro™ | 3.0L 150hp FourStroke, Pro XS and SeaPro | 4.6L V8 and 3.4L V6 175‑300hp FourStroke, Pro XS, SeaPro and Verado® | 2.6L L6 200‑400hp Pro and Verado | 7.6L V12 500‑600hp SeaPro and Verado

The RB100-HP Is Great For Powering

Anchor V2 230216 114031


Recreational 230216 114025


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