Don't Blow Your Battery Tender
 

I blew my Battery Tender by starting the car with it still hooked up and powered. I suspect a diode blew inside of the Battery Tender from generator current. To avoid this, simply unplug the Tender before starting the engine. Luckily it was still under warranty and a new one is on the way.

Phil

Re: Don't Blow Your Battery Tender
 

Are you referring to the brand name 'Battery Tender' or a different manufacturer?

Re: Don't Blow Your Battery Tender
 

Yes, it is a "Battery Tender" brand. It's probably good advice with other brands too.

Phil

Re: Don't Blow Your Battery Tender
 

Yeah too bad they don’t include an outlet wire circuit breaker for over amperage protection.

Re: Don't Blow Your Battery Tender
 

That's good to know.

Re: Don't Blow Your Battery Tender
 

Thanks, I have a battery tender and am always starting the car without unhooking it. Thanks again for the heads up.

Re: Don't Blow Your Battery Tender
 

Most standard type battery chargers should NEVER be used as a power supply for testing electrical components such as lights or motors as they are not designed to do this. Some large chargers have the capability to supply a couple of hundred amps for a short period to jump start cars. Battery chargers are just battery chargers ONLY. Regards, Kevin.

Re: Don't Blow Your Battery Tender
 

I think you may have had a bad unit. There has to be protection for high amp draws. They put out like a 1/a and that is it. Generator current should go to the battery before the tender because that is the path of least resistance. It is a good idea to unplug it first because you do not want to drive off with it plugged in.

Re: Don't Blow Your Battery Tender
 

That's probably good practice, I've been known to start the car with the tender plugged in. There is a fuse in the line of the leads that go on the battery. That came in handy for me one time when I was switching the charger to another battery that had a lead on it and mistakenly hooked the two batteries together.

Re: Don't Blow Your Battery Tender
 

I’ve seen on BT a line fuse on the positive cable and I assumed it was to stop back feed over load