The black box has the characteristics of an opto coupler and is controlled by the GEL BMS with a 0-5V signal.my question is has anyone got a similar control on thier Zivan as it would be handy to make use of it but i don't know how to ?
This modification, according to the guy that wrote the BMS software, was made in an attempt to control the charger to pull back the current supplied in the latter stages of the charge.
To be more precise, it does not regulate the current... it regulates the voltage (which will of course affect the current, so the statement is not entirely wrong)
The voltage can be adjusted 10-20% only.
In my humble opinion this is a hack that has little to no effect, and we've therefore decided to cut the connection to the BMS and refit the multiturn potmeter (details on the potmeter is to be found here: http://www.diyelectriccar.com/forums/showpost.php?p=353628&postcount=2)