I was wondering if I could connect a bulb or 2 to the terminals near the ecu via alligator clips to discharge the HV pack? Is that a bad idea? Would there be exposure to high voltage when doing so?
There are some threads in here about doing just that The dischargers that most of the battery charger makers sell is basically a black box that you plug a halogen light into That's what they recommend anyway using something like a halogen light one that uses you know like 300 watts or something along those lines there should be instructions all on this site about how to use those things and probably how to rig up your own but it is pretty much just that simple but you really need to read through here they'll be tons of warnings and all sorts of safety discussions that you probably need to and want to adhere to I am not a safe person but there should be tons of literature here on discharging and recharging the HV battery in a home setting situation
Those two relays are normally open, so attaching where you have circled will generally do nothing (unless you energize the relays somehow). Attaching to those relays by the terminals on their other ends would work. And yes, it would definitely expose you to high voltage. Be aware that blindly discharging a series stack of 28 modules is probably not what you want to do, unless you will be constantly monitoring the voltage across each module or at least across each block (the way the car does it). Whatever module reaches full discharge first can be at risk if you keep discharging the whole stack past that point.
If you do use this method, please purchase a bulb specifically designed for high DC voltage. There are bulbs available rated for 250vdc. Often they also designed for heavy duty/vibration resistance use on industrial equipment. I've never even tried to use a standard bulb for something like this, but maybe they have DC ratings on them also. I've never really paid attention.
I've used bulbs on past hybrids without issues. I would use them to 0 out nimh packs to bottom balance them. Hook up a 100w bulb, come back in a few days/week
Two 120v 40 watt incandescent light bulbs connected in series consume ~350mA at ~220 volts on the battery.
