Got the solar panel working (loose connection at the Kyocera was all).
Roughly planning out the next steps
Either way, I'll be upgrading the solar panel
- If I need MPPT, update solar controller ($150)
- Buy new solar panel (maybe two?) ($200ish per panel)
- Get solar panel fittings for 56" width yakima roof tracks ($50ish)
If I stick with AGM
- Buy new lifeline 210Ah battery ($650)
If I venture into LiFePO4
- Decide where to store them (outside in current position is sub-optimal)
- Roughly $1000 per 100Ah (Do I need to get up to the 210Ah of the prior setup?)
- Replace Trace M2512 inverter/charger with something appropriate for lithium ($600-700ish)
- Some risk that I'm muppet something up and bork part of the system
- I am assuming I'll be able to route the alternator, generator, solar and shore power via the inverter/charger and that I won't also need to get additional DC to DC charger (like the KISAE DMT-1250 I have seen reference in other threads)
I don't have an obvious place inside the van to put a 100Ah LiFePO4 but I figure I could make it work. Putting a 150 or 200Ah LiFePO4 seems out of the question, unless I did something drastic like pull out the (rarely used) suburban hot water heater.
Alternatively, I could slap a LiFePO4 (with battery heater) in the undercarriage carrier. It will get hot out there, bad for any battery, and the batteries I have seen don't fit nicely into the carrier. The undercarriage carrier has length 20.8", width 9.1" and height 9", perfect for the 12v AGM 210Ah batteries... (although this no-name brand LiFePO4
is *almost* a perfect fit....)
All in all, sticking with the AGM is the simpler option. The LiFePO4 offers some enticing capabilities, with a hefty price increase, some technical risk (if I self-install) and some uncertain choices about battery placement.
One question that stands out for me is: if I go with a 100Ah LiFePO4 battery over the 210Ah AGM, how much am I going to notice that missing 110Ah?
As Greg/Scalf77 has said elsewhere:
"Output voltage and current.
Lithium batteries have almost a flat discharge curve compared to lead acid, so the voltage output at 20% discharge is the same as 80% discharge. While lead acid the voltage output drops greatly between fully charged and 50%. Remember power (watts) = amps X voltage, so as the voltage drops the current needed to power a device goes up. Also, there is minimal Peukert’s losses for high current loads, so lithium’s are better for high draw inverter uses."
So, while I can't quantify that difference, I see how the 100Ah of the LiFePO4 would easily outperform a 100Ah AGM. But 100Ah LiFePO4 vs 210Ah AGM.... surely i'll have less juice to go around.