Thursday, August 27, 2009

Preliminary 216V Front Wiring

Design is in progress on the 216V upgrade. Here is a preliminary drawing of the front wiring. The grey box highlights the replacement relay board. All of the components are sized so that I could upgrade to 316V in the future if I want.

You can also download a PDF.

Wednesday, August 26, 2009

Time to upgrade the batteries

I am finally sick and tired of the mess that flooded batteries make - the latest is a fault in the HV isolation caused by the acid mess, leading to problems with the 12V system among other things. So, I will be upgrading them to sealed AGM over the next month or so. I thought about lithium, but it is still a little too rich for my blood (I think I would have to spend 10-12K on lithium + BMS).

Here is the plan which I've put in motion:
  • 18 Concorde AGM-1280T 80Ah 12V sealed AGM (same as in the ElectroJeep)
  • System voltage 216V nominal (230V at full charge, 190V at 10% SOC)
  • Manzanita Micro PFC-20 charger (same as in the ElectroJeep)
  • Manzanita Micro Mk2 analog regulators (so as not to kill the batteries via inbalance)
  • Upgraded DC-DC converter (probably the APS-55 220V - the Zivan NG1 was suggested but I have worries about its use at other than full charge)
  • Various other upgraded components (relays, fuses, heater contactor, battery interconnects, etc.)
This will give me 17kWh nominal pack size (compared with 23kWh for the floodies) - but I'm willing to live with the potentially 25% reduced range for the tradeoff in reliability, convenience, and power (the pack will weigh about 200 lbs less than the original, and the higher voltage will gain perhaps 10% in performance, for a net of nearly 20% perf gain)

Stay tuned, I'll update with more details as they evolve.