Bob - helpful info. On the HCH - do temp sensors already exist? One would think they would as charging a overheated battery would be a problem with the stock system. I know that I have read that on really hot days the battery stops working so presumably the sensor exists and you just need to tap into it.

Now as far as dV - that would seem to be pretty easy. If you use a standard "trickle" battery charger - do they typically have a dV sensor? I would think any good charger would have this - yes?

I know - getting to the right voltage, checking dV and tying into a temp sensor - will probably take enough time and money that I should wait for the manufacturers to do it.