Hi Marty,
I'd like to reopen this theme. Did you ever find out about these changes to the TBM CB?
The reason I'm asking is I have a single and a twin battery model, and I intend to finish the twin first so I need to get the facts now. I saw the additional circuitry in the cct diagram but never check on it's use assuming that I had two single battery models, then I run into this thread while looking for other info,
I have opened both CBs so I can check the butchered one, the non butchered CB is from the TBM and was still sealed. After reading this thread I've just run an A/B check on the two boards, the only difference I can find is the material used as links, plus there is no link between pins 7 and 8 on X6.
Did you ever check the function of the TBM circuitry? If not I'll have to try and find some time to figure this lot out.
Cheers. KarlG.
P.S. Do you have an accurate figure for CB shunt resistance?