SiPMerlin150
Member
- Messages
- 987
- Location
- Sunshine Coast, Queensland
I've done and experienced many reapirs (mig welding) to cars leaving the battery connected (risk taking, i know) with no problems, until I did a repair on my own car. That night after welding the car started fine as usual. The following morning the battery was flat, charged it up fully, and popped it into the car, started fine for the rest of the day. Again, the next morning it was dead. Jumped started it and drove to work (6 miles) and tried to restart the car as soon as I switched it off...Nothing, still flat.
Turns out the battery was screwed but the alternator was all good and healthy. Popped in a new battery and all is fine...
My theory:
I've used gas MIG with a negative work return and this is connected to the body of the car, which serves as a common ground for the cars electrics, thus being connected to the negative side of the battery. So in effect, its a neutral connection.
However my home welder is gasless with a positive work return...so i'm thinking that I have been feeding positive power direct from the welder to the negative side of the battery... This may have screwed it up.
Thats my theory. I'm daft and it only cost me a battery, (new one was free anyways..) Next time the battery will be disconnected.
Lesson learned. Lucky not to fry ECU or set airbag off
Turns out the battery was screwed but the alternator was all good and healthy. Popped in a new battery and all is fine...
My theory:
I've used gas MIG with a negative work return and this is connected to the body of the car, which serves as a common ground for the cars electrics, thus being connected to the negative side of the battery. So in effect, its a neutral connection.
However my home welder is gasless with a positive work return...so i'm thinking that I have been feeding positive power direct from the welder to the negative side of the battery... This may have screwed it up.
Thats my theory. I'm daft and it only cost me a battery, (new one was free anyways..) Next time the battery will be disconnected.
Lesson learned. Lucky not to fry ECU or set airbag off