Measuring sub pack voltages

JimIsbell · 09-28-2008, 11:13 PM

Has anyone found a way to measure the voltages on sub packs of cells in the IMA without removing the battery from the car? Maybe it would be possible through the 10 taps that the computer uses to measure the voltages in the battery to measure, at least, "two pack" voltages to narrow down the search for a possible bad sub-pack?

retepsnikrep · 09-29-2008, 12:33 AM

It's perfectly possible to use the subpack monitor wires to measure the voltages of pairs of subpacks. I will certainly investigate real time monitoring of these 10 points when I have finished my BMS project.

It would be nice to be able to monitor any imbalance in realtime and perhaps send a small balancing charge (50ma) down the wires if reqd (The 180R resistors in these lines would limit the balancing current). I like the idea of adapting my bms so it can piggyback these connections and monitor/balance the pack via the plug/socket. just need to be able to source the plug and socket used on the oem pack/bcm

any ideas anyone.

The easy way to balance is the 250ma whole pack overnight charge.

**IamIan** · 09-29-2008, 06:31 AM

Mike D sources some of the connection plugs for his latest batch of plug in MIMA systems... I do not know if that plug is one of them or not... I know Mike said there was a significant size minimum order to get the ones he did get ... no onesies twosies .

JimIsbell · 09-29-2008, 06:54 PM

If the car is out of warranty, as mine is, then cutting the cable to insert an easily obtained connector set is easy enough.

**IamIan** · 09-30-2008, 04:10 AM

Quote:

Originally Posted by JimIsbell

If the car is out of warranty, as mine is, then cutting the cable to insert an easily obtained connector set is easy enough.

very true... and likely to be a direction I might head myself one day... but before you go cutting and soldering into those wires directly... plan out the rest of the system so you know in detail what you are going to do with those voltages once you have them.

JimIsbell · 09-30-2008, 10:28 AM

My plan is for a "T" connector with jumpers so that I don't have to plan ahead. I can, at any time in the future, open, close, or tap into any data stream at will.