Lithium Upgrade 8: Smooth Sailing

The plan to use the boat as an EV charger is back on track and working!

The curious behavior of having two Lithium Iron Phosphate (LFP) batteries in parallel had stymied my attempt to keep the Sun King’s solar power system busy while offloading some work from the main system.  The main system needs to be able to keep the house cool.  With temperatures hitting 100 this week (that’s real degrees, not “feels like”) the a/c is much appreciated, but not at the expense of a big bill from the power co-op.

What was happening, when starting from full, plugging in one of my farm vehicles would drain only one battery to a certain point.  Then the other battery’s Battery Management System (BMS) would turn on and try to charge the first battery and the trucklet, drawing more current than the 100 amp breakers could handle.  Breakers that would have been big enough had there been a single battery, popped on both batteries.  I put a new 200 amp breaker on each battery and all is now well.   The batteries will EACH handle more than 300 amps, but cooking supper, the largest normal load, uses a fraction of that and 200 amps takes care of the charge station requirements.  The new inverter can run 1500 watts all day to the buggy in 100 degree heat with no problem, so I am pleased with that improvement, as well.  If I can get some motorcycle time in this week I will up the ante and charge the Zero electric motorcycle along with the mini trucks.  See what this thing can do!

Boat inverters
The new inverter, on the right, has a lower rating than the one on the left, but actually meets spec and is performing well in the heat.

Still no sign of the electric flying machine, so no chance to test that yet.

Lithium Upgrade 8: Smooth Sailing 1

EV fleet to be charged by the boat.

I am still thinking added capacity on your home system is the best way to go for charging an EV, but in this case I had some unused kilowatts just sitting around doing nothing.  Hopefully I will soon be done with some other repairs and upgrades on the boat and get back out on the river where it needs to roam.


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