Lifepo4 battery in 1990 Lance?

steveh27 wrote:
When I replaced the 105AH lead acid battery in my Class B, with no space for 2 batteries, I contacted a lifepo4 manufacturer in China that advertised on Amazon. I gave them the size of my battery box & they built 2 100AH LiFePo4 batteries which fit. So I went from 50 usable amps to up to 160. I never drained the lead acid battery to 50% only 60%, and I do not expect to drain the LiFePo4's to 20%, but it is nice to have that capacity.

They had me buy them through Alibaba for a lower cost. Prices have come done since I bought in 2019.

I contacted Power Dynamics re my charger and they said only to push in the boost button to get the max charge.

I’m using the ‘standard’ Progressive Dynamics 9245 with added Charge-Wizard dongle used to kick the charger into it’s 14.4v Boost mode - Per the Victron BMV 712’s bluetooth-Smartphone detailed menu display’s, charging goes on without a hitch (very little internal resistance needed to overcome)...

Shortly after the (Li programmable) Victron’s 100% SOC ‘end of charge’ parameters have been met (e.g. V and A hold steady for a brief period...), you can watch as the Li’s internal BMS begins it’s sequential current and voltage cell-balancing dance, whereby cells of a higher potential will bleed any potential excess charge to sister cells of a lower potential, and where any remaining charge deficit is resolved via a final charger top-off (verifiable as voltage holds at a steady state and charge current stops).

Once cell-balancing is complete, there’s no real need to carry on with an active charger (this, contrary to conventional FWC charge objective - a kinda non-intuitive thingy - lol) in an attempt to maintain FWC’s traditional ‘holy grail’ of ‘on or near’ 100% SOC (recall, very little voltage sag throughout the entire Li discharge cycle)...So for this and for purposes of longer term storage I simply added a basic battery post-top disconnect switch which allows the converter-charger to carry on in it’s roll as a 12v RV power supply...

When charging, I only occasionally charge to a full 100% SOC, since cell-balancing is only necessary periodically - with it’s greater operating breadth, Li is quite happy somewheres in the mid range, even if running the air conditioner from inverter..

For longer term storage, the Li is happiest to hibernate along at about 50%ish SOC (cations and anions in approx. steady-state equilibrium), and not much monitoring is required due to Li’s uber low tendency to self-discharge...

Hope this helps the uninitiated!!

3 tons