Upgrading converter

StirCrazy wrote:


I see what your saying. I guess if we stay in that area that skews the numbers the advantage will be on the smaller side but what if we are looking at using the genny from 65-100% how much differentce is there then. this is more where I lived with my GC batteries and solar instead of a genny. I would be at tht 60 to 70% mark in the morning and recharged by 1 to 2 pm to 100% I did drain down my new battery pack by about 45AH in the drive way an did a simulation and it was recharged by 11:38am. hardly scientific but a simular amount that needed to be recharged and a significantly faster time.

I guess I just have a hard time understanding with how cheep solar has gotten why we are still talking generators unless you have to run an AC.

That's easy--for when there is no/not enough solar. Eg we go to Rathtrevor park in the woods for four days in February, temps just above freezing. No solar in the woods. Park rule is two hours gen time morning (we don't do it at night in the dark outside)

460AH bank is about 400AH at those temps. 75 amp charger biggest can carry due to limit of size of portable gen we can carry in the RV spaces so stuck with that 75 amps limit.

75/400 is a 19% charging rate and that means Bulk ends at about 78% SOC before amps taper. After two nights next morning (day 3) we are down about 230 AH so about 43% SOC so fire up the gen for the two hours.

Get 43-78% with constant 75 amps is 140AH at 75 amps = 1 hr 56 min so get 4 minutes with tapering amps, not tapered very much. Heat loss 6%?
So AH restored is say 132 AH (which is close to what the Trimetric says so that works)

If we had LFP we still use the same AH a day. Same two hours limit with same 75 amp charger limit

= 150AH vs 132AH so the LFP gets you 18AH more in the two hours.

In our case 18AH more restored to get us to Day 4 would not make any difference, so no reason to swap to LFP. Absolutely need the gen to go at all whether LFP or FLA or whatever kind of battery.

Happens that four 6s are perfect for that job in our RV. YMMV Haven't worked out how big in AH the LFP bank would have to be to do two nights and 230AH before needing to recharge morning of Day 3 and cost of that compared with cost of four 6s.

In fact if there were sunshine you might still be doing some gen time high amps in the morning and solar low amps but with more time the rest of the day to get to full recharge or as high in SOC as possible that day.