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[crx_rogus]

Folks -
Hello again.

If all goes well, this Sunday I pick up a quite healthy 2000 silver 5spd Insight, paying $5400. (Test-driving the car was intriguing, interesting in a way I have never experienced before.)

The seller already gave me a spare battery pack he had. After finding a wide range of no-load subpack voltage levels, I ordered a Prodigy II multicharger. After refreshing all the subpacks in both the spare and currently active packs and finding them all hopefully healthy enough, I'd like to well + safely mount and connect the 2nd pack in parallel in the Insight. Any pics/tips anyone can point me towards regarding secure mounting points/methods for the 2nd pack?

I also plan to use a connector harness to get each subpack paired up with its twin across the two packs to maximize balancing, minimize cell overheating, restore the effective total capacity to about what it was to when the BCM allowed a 20 - 80% SOC range from a single pack, and perhaps most importantly ;> bypass the mythical Ovionics/GM/Texaco-Chevron/Cobasys 10 amp-hour limit for NiMH EV battery packs.

Per my much earlier PHEV-Light thread, I'd then like to go for at least occasional home-based charging, which the 2nd pack would make more worthwhile. It looks like 172V is about the maximum the pack should be kept at I gather, with 1.43V/cell leaving a 0.3V or so inter-cell variation allowance margin at 8.6V max per subpack. Has anyone tried a zener diode -based + current-limited arrangement where, only under home recharging, the subpacks are limited to 8.6V via a pair of 4.3V zener diodes in series (from allelectronics.com) across each subpack (or paired subpacks in this case)? I understand NiMH internal resistance doesn't vary across most of the SOC range, until dipping at full charge and then climbing steeply (which is where the zener-based voltage limiting would kick in). That should (in theory at least) allow balanced and safe but full subpack recharging.

Has anyone tried that approach and found it to work well? I realize with the pack seeing up to around 180V peak under full 50A regen all those 1W zener diodes would have be connected only under home recharging, either via a bulky >21 wire connector where the zener diodes are all on the recharger side of the connector, or a simple power connector with the zener diodes all getting dedicated normally off relay connections (4 5PSTs would be needed), powered on by the recharging power source.

Thanks for your very helpful answers you've provided to my many earlier questions.

I am really looking forward to having such efficient and interactive engineering, where energy given back by gravity and momentum can actually be stored for later use, as my everyday transport of choice.

Regards,
Roger