Lithium Pros LiFePO4 batteries, small boat battery perfection?

Ben Stein

Ben Stein

Publisher of, passionate marine electronics enthusiast, 100-ton USCG master.

27 Responses

  1. Will the N2k connection sum the totals of a parallel bank or is it just for use with one battery?

    • Each battery is addressable on the NMEA 2000 network individually. So two batteries in parallel would show up as two entries in the list of devices. Choose to display information from one or both.

  2. Hi Ben, great article and looks like a great product. I currently have 3 dead Group 31 AGMs in the back of my Jeep. They were the start batteries for my Foretravel Motorhome. They weigh over 70 lbs each. Thought these batteries may be a fit for me to match up with Li House batteries but at $2K each or 6K Total, guess I will continue on to Sam’s Club and pick up some more AGMs at $135 per copy. Sure could supplement my House Batteries nicely though.
    I am no longer boating, but still follow Panbo looking forward to your articles. Keep up the good work and thanks. Herb Stark

  3. Ken says:

    I’m glad to read your review of LP’s marine batteries. I purchased, a year ago, two RE 129ah for our Class C RV. I am well pleased with their performance. I understand that the BMS is internal with no external readout like the one you have reviewed. I don’t know of an app to check performance of the RE line. Any suggestions for adding a monitor would be appreciated. Thanks again

  4. Mic Fite Mic Fite says:

    Well, Yet Another Great Article! That you actually did capacity tests AND a tear-down in addition to in-situ testing is one of the reasons I appreciate your in-depth investigations and well written reviews.

    As for these new batteries from Lithium Pros… FINALLY! Someone has integrated super caps (or ultra caps) into a battery for engine starting, not to mention their other benefits. This is something I’ve contemplated for many years. I tried to buy some Maxwell Technology super capacitors a few years ago to experiment with, but the big ones are hard to source for an individual. And I suspect that most that you see on Amazon and Alibaba are counterfeit and/or unknown quality. Anyway, your tear-down reveled the ultra cap secret in these batteries and good quality ones at that. And nice BMS, too. The number of FETs, attention to heat dissipation and big bus bars are indicative of a robust design.

    (Note, that with no option for an internal heater these batteries would not be appropriate for active use in freezing temps or below. Probably noted in the manuals.)

    I know some may balk at the price, but when I consider the quality of the cells, BMS, ultra caps, NMEA networking and the engineering that went into these products I think it is reasonable.

    That said, I would like to see someone make a small (i.e. group 24 or smaller) battery that was more ultra cap and less Li cells for starting my sailboat engine (39hp), at a attractive price. Maybe that’s the model C682?

    Good job Ben, and good job Lithium Pros for the innovation.

  5. William Hitchen says:

    I am curious how the charge current was limited. I work on Yamaha engines and there charging is not the best. The Lifepo4 batteries I have installed in the past require a special alternator or a DC to DC converter to limit the amperage draw on the charging system. Is this built into these batteries?

  6. Dan Barthel says:

    Your article motivated me to google superconductors. There appear to be lots of standalone superconductors which could be added to existing battery banks (thank the idiots whose bass shakes the whole parking lot) So you can have the advantage of the LiPro battery on your existing battery bank.

  7. Dan says:

    Supercapacitors. Mind-blowing! I wonder how long until someone provides a true drop-in solution, by supporting high starting currents we are one step closer to emulating a lead acid battery, one that can also emulate the voltages of a lead acid battery including adjusting the output voltage to accurately reflect the battery state of charge so well our existing battery monitors function normally.

  8. Gary Warner says:

    Hi Ben – Great article on a very interesting product. My question related to using these batteries in a house bank configuration. Is there any limit to the number of 110Ahr batteries that can be paralleled? I’m interested in paralleling 4 batteries.

    • The battery in the article is designed for engine start and is therefore limited to 2 units maximum in parallel. They are really intended for individual operation. We are working on a different product for larger, paralleled banks for energy storage.

  9. Mic Fite Mic Fite says:

    This article rekindled my interest in using super-capacitors for cranking, and so I was poking around on the interwebs and found this product:
    A lot more basic than the Lithium Pro battery, and not suitable for house loads, but if you were looking for something to replace your start battery this is interesting with a price that is comparable to an AGM. Might not be available out side of Australia, though.

  10. Larry Olson says:

    Question: What device did you use for the capacitance test?

  11. We have been using these for some time as a starting battery. On the farm we use it on all the tractors including a Case 580 backhoe. WAY better than lead. Addressing Ben’s concern about running out of charge, checkout the “re-start” feature.

    • Butch Davis says:

      That’s a clever feature. Boats, in particular, with the usual two or more batteries may not find it as useful as will single battery mobile equipment and, possibly vehicles.

  12. Bob says:

    Where are Lithiumpros manufactured?

  13. Dan says:

    Kevin, I am confused over some features Ben wrote about. Ben wrote ” if the BMS disconnects due to a fault condition, the supercaps stay in the circuit.” and went on to explain some benefits that confused me.
    (1) “if the BMS has disconnected the cells, the supercaps will be able to start the engine”. Won’t the supercaps substantially discharge from the time of disconnect through the several minutes an owner might need to check on an alarm, diagnose they need to start the engine, and start the engine? Particularly on a sailboat under way there could be items like an MFD, other displays, AIS, navigation lights, a fridge?

    (2) “Without supercaps, if the alternator is working hard to charge the battery and the battery disconnects, the energy generated has nowhere to go. The result is potential alternator damage. But, when the supercaps are in the circuit, they will serve as a snubber or protection for the alternator.”. Presumably the super caps are 100% charged if the alternator is running (or is it not?). E.g. if the LifePO4 battery is 80% charged isn’t the supercap likely to be 100% charged? At full charge, how do fully charged supercaps absorb a significant amount of voltage spike from a load dump?

    • Ben Stein Ben Stein says:

      I’m hoping Kevin might answer on the first question, but I think the reality is that if you have house type loads on the battery, you’re likely to quickly deplete the supercaps and still have a problem starting the motor. On the other hand, if the loads are low on the battery, it could well keep you out of trouble.

      For your second question, I think I can chime in. The bank of supercaps is made of six 3.0 volt caps. That’s an 18 volt bank. But, the bank will be held at the voltage of the charge energy coming into the battery. That’s likley to be around 14 volts. In a disconnect event, the batteries would stop accepting charge. As a result of that charge not having anywhere to go, voltage would rise. With 4 volts of “headroom” the voltage would rise momentarily, and the supercaps would absorb that voltage. At the same time, the regulator of the alternator (internal or external) would see the rising voltage and pull back field to shut down production. That would happen in time, and the alternator would be preserved. At least, that’s my understanding.

      -Ben S.

  14. Dan says:

    Yes, that makes sense.

  15. Alex says:

    The supercaps idea is interesting but I’d like to know how it would work with a thruster (or if LPs battery is ok to use with thrusters…).

    I have a 40′ Mainship and the current wiring is designed to have the thrusters on the house bank instead of the engine start bank. It would take a fair amount of work to separate this and I do kind of like that design. Could these batteries deal with the amperage of bow and stern thrusters docking?

    • Ben Ellison Ben Ellison says:

      Hi Alex, I’m not as knowledgable about LP batteries as Ben Stein, but I do have a thruster that’s running fine on a LiFePO4 house bank. Specifically, I’ve got four 100A Victron Lithium Smarts heavily cabled to a Lewmar 4kw TT185. The batteries are rated at 200A maximum continuous discharge each, with 100A recommended, while the thruster can purportedly suck up 470A.

      So, at least theoretically, I’m slightly exceeding the 400A recommended maximum discharge rate of my bank, but then again I’m almost invariably running the engine when using the thruster so the house bank alternator is adding another 100A plus. Also, I’ve never seen anything close to 470 amps on the bank’s current monitoring, which I suspect is a combination of shunt inaccuracy with short bursts of high amperage and Lewmar possibly overstating the power draw so installers don’t scrimp on cable sizes.

      At any rate, my battery system has not complained and, in fact, the thruster seems a little zippier, as do all boat’s other electric motors (thanks, I think, to the higher LiFePO4 voltage).

  16. gary hall says:

    I am planning one LIPO4 alongside a lead acid cranking in order to run dual Yamaha 150’s with the Perko switch on 1+2. the below statement about alternator damage or overcharge has me concerned. I have big drain currently on one of the Yamaha LA batteries due to all the electronics and live well electric draw so wanted to switch out that one with lifPO4. Any thoughts?
    William Hitchen stated December 15, 2022 at 10:39 pm
    “I am curious how the charge current was limited. I work on Yamaha engines and there charging is not the best. The Lifepo4 batteries I have installed in the past require a special alternator or a DC to DC converter to limit the amperage draw on the charging system. Is this built into these batteries?”

    Kevin Bennett December 21, 2022 at 10:47 am
    “Charge current limiting is not built into the battery.”

  17. gary hall says:

    read a recent article that stated a battery isolator is needed in between the cranking lead acid and the lifepo4 deep cycle to be connected together in order to charge from my outboard alternator and the boat system?

  18. John Welch says:

    I am curious if these batteries could be safely charged by an older charger that doesn’t have a lithium battery profile?
    We have an older charger/inverter that can work with flooded, AGM, or gel but Xantrex recommended to not use Li unless it was compatible with an AGM profile.
    Would the super caps allow this battery technology to be charged by one of the traditional charging profiles? That would be great. Even though these batteries are more expensive than other lithium batteries when the cost of replacing the charger/inverter is includes this may be a good deal.

    • Ben Stein Ben Stein says:


      I wouldn’t advise that you try and charge these, or any other LiFePO4 battery, with a charger that you can’t adequately control. The supercaps aren’t going to do anything to reduce the voltage that the cells see. In fact, the supercaps are actually rated for higher voltage, so they will happily increase their voltage if the charger does, but that increased voltage will also make it to the BMS and cells. At a minimum, that will cause a high-voltage disconnect event.

      My biggest concern would be that most chargers aren’t transparent around temperature compensation. If the inverter/charger is temperature compensating, the voltage will increase and, as I mentioned, the supercaps won’t do anything to stop that increased voltage from making it to the batteries.

      -Ben S.

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