Quote:
Originally Posted by hemiallen
Sorry for all the questions, but I don't have other resources for asking this, so far.
I did another draw down test, dropping my now 400Ah BB lithiums down to 75% -13.43v.
PD 4575A charger, factory Montana 4 gauge wire. Stared using my generator and finished with shore power, no difference seen in charging rate.
Started Charging at 51.59Amps as measured on Victron smart shunt and tapered down as batteries recharged.
I have 400Ah of Battleborn Lifepo4 that I need to recharge using my Honda 2000I generator. The trailer has a PD4575A converter, and I ran my battery bank down to 75 percent / 13.43V. Recharging the bank started with 51.59A at 13.43v ( total loss was -102.6 Ah) and gradually reduced Amps while increasing volts using my victron smart shunt measuring battery status. After 2 hours it was 13.62V and 39.38A ( -12.7Ah) and after 2 hours 45 minutes it was fully recharged at 14.55V, 0.76A and 0.0Ah loss.
This seems longer to top off than the advantage of Li batteries should take, all I want is to maximize recharging times when boondocking. It seems AC recharging isn't a readily found component for a decent price , and my 300W solar isn't as useful as my generator for where we camp.
Is there any way to get a faster recharge out of my 2000I generator, which running puts out an advertised 1800w? I wish to maximize my recharge time with this generator, but am willing to get a higher output generator if I can find an AC-DC charging system for times when I want a fast recharge, knowing this reduces the life of the batteries. BB states a suggested 50A / per battery so I could go as high as 200A, but realize that probably needs more AC watts than I care to take with me when boondocking. The largest I have found is a Victron 120A inverter-charger, but I only need the charging system.
My current thoughts are: plan to drop my batteries to a lower state of charge than I did in this test, and just run the generator a few hours a day to recharge some of the loss, and when I get the bank low enough either recharge longer, go find shore power for a day to recharge to 100%, then continue boondocking.
I am used to boondocking with L-A batteries, so maybe I just need to learn it's ok to drop to ~20% capacity before recharging them some? It is hard for an old dog to learn new ways , maybe the above is the route I should take....?
Thank you very much
Allen
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It doesn't matter what generator you are using, the converter is never going to put out more than it's designed to and probably not even that much. Use Watts when doing these calcs as it eliminates the need to convert and avoids the risk of a conversion error. Here are some salient measurements.
The gennie c an put out 1,600W steady
The Converter puts out 75A if I remember the model number code correctly but I think the max you saw was about 52. That maybe caused by converter inefficiencies or wiring. I use 4/0 wires for the battery interconnects and from my inverter/charger to the batteries. My converter is totally disconnected freeing up a breaker!
At roughly 60A you should have no problem re-charging 102.6AH in under 2 hours but the last little bit does take a little longer by design. How is your Battery Monitor set up, that might make a difference. My batteries just reached full charge about an hour ago, here is the chart. You can see there is still some charging happening after it reaches 100%. I also included a calculation for 4AWG wire, I use 4/0 and the result for 10 ft is 0.5% but my run is less than 3ft so it's 0.15%