Build one yourself. the hook up to the car is just 4 wires and a inline safety fuse. Peter has a how to video on youtube to build one.Second question is what would be the right steps to try to diagnose and revive the IMA system if I have no access to a grid charger/discharger?
Just put your car into gas only mode, and then jump start the car, see if the 12 volt holds a charge. I'm assuming your 12 volt currently dies on you and kills the engine. The IMA system acts as the cars alternator, when it detects that the hybrid battery is having an issue, it disables itself, so your 12 volt will slowly die.My first question is can I plug in a trickle charger/maintainer into the 12v socket to at least try to get the 12v battery up to a good charge?
Youtube will show you multiple videos of how to put it into gas only mode.
If you can't find a decent autoparts store to sell you a car battery, I've been told a few members here use a golf cart 12 volt battery because the insights reliance on the 12 volt is so little, not sure if/how that will interact with the IMA battery not being functional so I'm not going to suggest it, but in a pinch if you're in a rural part with little access to parts it might be worth a try.