Lithium over Lead Acid Batteries

[Overtaxed]

Finished the install of my new 100AH ACDC battery last night:
https://www.adcbatt.com/products/adc...collection_1.1

First thing I tried was a generator start, worked without issue. This battery does have a 200A 3sec discharge which, apparently, is enough for the Onan to kick over.

Interesting discussion with some scope data for an Onan.
https://diysolarforum.com/threads/am...ranking%20Amps.

[Tom Traveler]

Didnt see this thread earlier. On my 399, I had the Onan 5500 watt generator and 1 Lions Energy 105AH battery (UT1300), and there was never any trouble running the generator, and I used it pretty frequently.

Glad I found this thread because I had the same question. I have a propane Onan 5,500 watt generator. I put a clamp-on ammeter on the positive starting wire from my LA battery bus. While watching the ammeter continuously, the current spiked at just about 100 amps during generator starting. It can crank longer than 5 seconds if it hasn’t been run for awhile so I think some lithium BMSs for one battery could shut it down but probably not. Two batteries should have no problem.

[Redapple63]

Glad I found this thread because I had the same question. I have a propane Onan 5,500 watt generator. I put a clamp-on ammeter on the positive starting wire from my LA battery bus. While watching the ammeter continuously, the current spiked at just about 100 amps during generator starting. It can crank longer than 5 seconds if it hasn’t been run for awhile so I think some lithium BMSs for one battery could shut it down but probably not. Two batteries should have no problem.

I think you need to look at the burst rate of the BMS not continuous rating. Many of the lithium batts have 200-300 amp burst rates for 5-15 seconds. That should facilitate starting of high draw devices.

Bill

[ajg617]

The BMS on our Battleborns allow 100amps continuous, 200amps surge for 30 seconds, and 1/2 second surge over 200 amps.

[avidcamper]

I have been thinking of going lithium. Being up in NY there are time where it drops below 32 degrees. Are there some batteries that have internal heaters?

[SolarPoweredRV]

I have been thinking of going lithium. Being up in NY there are time where it drops below 32 degrees. Are there some batteries that have internal heaters?

Yes, there are. However, they are a bit more pricey.

The issue with LiFePo4 batteries in the cold weather is that they can not be charged if the battery temp is below 32 degrees.

There are ways to mitigate this issue:

1, don't charge the batteries in the cold. If you normally store your RV in the winter, simply disconnect the batteries until spring.

2, If you occasionally camp in cold weather, make sure your battery has cold weather protection (check out a tear down video for any battery you are planning to buy).

3, install your batteries in a space that won't freeze while you are using the camper, usually in a heated hold, under the dinette seat, or in an interior closet.

4, don't have your Solar system turned on in the cold weather. Your Solar system will attempt to charge your batteries whenever the Sun is shinning, so, if there is cold weather (or your camper is in storage) be certain the Solar is turned off.

5, build an insulated battery box with a thermostatically controlled heater for your batteries.

6, buy heated batteries, this will offer you the most protection, but it does come at a price.

[ajg617]

6, buy heated batteries, this will offer you the most protection, but it does come at a price.

Caution, the heated batteries draw amps when the heaters are on. So if you have no charge source connected to re-charge as needed they can draw down in a week if the heaters are on constantly.

[Gronk1]

Caution, the heated batteries draw amps when the heaters are on. So if you have no charge source connected to re-charge as needed they can draw down in a week if the heaters are on constantly.

I'm thinking about going lithium & am still learning here, so be gentle. I thought heated batteries draw from a power source & not from the battery itself when heat is needed (converter/charger). Or is it some manufacturers heat from a power source & some from the battery itself?

[SolarPoweredRV]

Caution, the heated batteries draw amps when the heaters are on. So if you have no charge source connected to re-charge as needed they can draw down in a week if the heaters are on constantly.

I am not sure, but I think the heaters are only powered if the battery is attempting to charged. I could be wrong, but that is how I would design the heater to work.

Obviously this is something to consider with the heated batteries.

[ajg617]

I'm thinking about going lithium & am still learning here, so be gentle. I thought heated batteries draw from a power source & not from the battery itself when heat is needed (converter/charger). Or is it some manufacturers heat from a power source & some from the battery itself?

Our heaters are 12V blankets that stick to the outside of the batteries, use 11-13amps/day/each if on all the time, and pull directly from a 12V source . New BBs have them built in - mine did not. They are thermostatically controlled. Can't speak for other manufacturers.

To give you an idea of what we ran up against this year, factory warranty on the RV expires April 2nd. Dealer wanted us to drop the RV before we left for NC for a month to do warranty repairs. Long range forecast was to hit -18F for two nights after we left so I installed heat blankets. Blankets and solar charge are all on buss bar with Blue Sea disconnect shutting everything off. Service advisor turned the disconnect on for the really cold temps - below -12F will damage the cells. The RV is still at the dealer likely with snow covering the solar panel so I'm not sure exactly what I'll find battery wise when we finally get to pick it up (they found other issues and are waiting for parts). More snow on the way but at least the temps are moderating. If it were in my driveway, I'd have it connected to 110V.

So this year was an odd one in that I had no control over charge/discharge of batteries now since mid-Jan and had to leave them in with no access to the RV while away. That said, I would put lithiums in again - worked great last year. SOC was as low as 20-25% and could still get the gen started.