siai47 wrote:You Cannot connect the additional battery to the inverter as you are bypassing the main contactor which is located in the battery pack. Bad things will happen unless you have a way to connect the additional pack after the "ready" light is on and disconnect it before the "ready" light is off. In addition, the I-MiEV battery is a lot higher voltage (just over 360 volts when fully charged) than the 322 volt battery you are using. I don't know what type of batteries you are using but if Li-Ion you will surely be overcharging them to a dangerous level. The only correct place to tap into the battery is inside the pack before the contactors. Or, if a Chademo equipped car, through the Chademo power cables. The codes you got most likely were because the car thought the main contactor was stuck closed. Remember, there are lethal voltages inside the pack so I am not recommending you go inside. However, if you match the voltages, the external pack will work if wired correctly---I have done it.
The extra battery is based on Li-Ion cells Sanyo NCR18650GA 3500mAh - 10A, connected 88 Serial and 6 Parallel that is exactly the same number of cells in series as in the car battery pack.
The 322 V was just the charging status of the extra battery and of the car battery when I connected them in the beginning. Now I have fully charged them in parallel and both packs are approximately 360 V.
I think it will be ok to connect directly to the motor inverter as long as I switch on the extra pack only when the car battery is switched on.
I am not connecting through the Chademo power cables because later I am planning to be able to run the car either on the extra pack or the car batteries or both in parallel. With the Sanyo cells I am able to pull 60 A according to the cells data sheet. Therefore I can drive the car with power up to aprox. 18 kW only with the extra pack. This pack is around 5 - 6 kWh so it should give aprox. 50 km extra range.