Hi. So I’ve got one of those large Schumacher upright battery chargers with the wheels on the bottom, that you can roll around, and it has a 225amp jump start feature. I’ve only ever jumped my riding mower and my old 79 chevy truck, and never had a problem, but I always did notice the lights always seemed to be extra bright when I jumped something. Today I went to jump my 95 astro van, and set it on, ran to crank it, and when i turned the key to crank it, i noticed the buzzer was super high pithched, like it was getting way too much power, the voltage gauge was right on about 13 volts, then it and the gas gauge died, the starter clicked, but didnt even turn over, and about 2 seconds after i turned the key off, i heard a loud spark sound in the dash, and my aftermarket radio started smoking badly. I tuened the charger off and was able to rip it the radio out of the dash and chuck it into the yard still smoking quite heavily.

Main question:

What happened here?

I always assumed if you were to hook up like 10 car batteries in parallel, it wouldn’t matter since components will simply use as much power as they need. And ive used plenty of jump start boxes before without any sort of issue. Are the jump start features on battery chargers somehow forcing the amperage through the wiring burning everything up? And why didn’t any of the fuses blow out? The radio fuse on the radio itself (10 amp) was still good, all of the fuses in the fuse box are not blown, so I’m assuming my gauge cluster is fried, I assume it somehow fried my starter as well. And who knows what else is burned up. Any ideas? Are these battery chargers known for frying wiring?