Just FYI once you’re charging faster than 6.6kW, there will be some potentially surprising interaction with the main battery pack, and any power tank attached adds some wrinkles.
I’m assuming you’ve already provided the basic programming of CC-CV programming where each charger operates at a constant current target until output bus voltage reaches a target where it tapers. All the chargers we’re discussing do this, and you mainly set target voltage and taper rate.
The interaction I’m alluding to has to do with using these to charge at higher C rates.
- For one, the battery will produce more heat, so mind keeping it in the shade if the weather is hot and sunny.
- Another issue is that a main battery pack and power tank might not charge at the same proportional rate, leading to one topping off faster than the other, which might open a contactor and stop charging early, and then you have to restart charging to balance the batteries to get them to pair up. This happens more when the batteries are from different cell generations (usually just different years).
- The SoC indication might drift a lot, too, depending on how repeatedly you charge. This varies and you might not see it at all, but basically if the SoC prediction algorithms get out of their normal patterns, it can happen.
- Mixing OEM chargers with third party chargers is mostly fine, but the chargers once tapering might shift load around a bit. I haven’t explored this very often, but dual J charging on ChargePoint where you get power graphs shows this happening and it can be weird. Usually I just shut off one plug remotely if that plug’s charger tapered itself to zero too fast.
So, mostly just keep an eye out, and probably the safe thing is to stop or reduce charging near 1C before topping off (80-85%, say) to get the most benefit and get back on the road. Try not to push the battery hard right to the top, basically, or be more careful when you do.