Can I use my Battery Tender on my classic car when not driving it?

I have been starting my car weekly, just to keep the battery from dying, but sometimes I forget, and the charge lessens. Can I keep the smart charger on it all the time when not in use? And if so, can I just leave the connectors on without disconnecting the negative terminal, or connecting to the frame as if I were going to jump start? Will I do any battery or electrical damage to the car?


First of all....Starting your car weekly just to keep the battery charged is not correct...

If your classic car has a dynamo it needs a long run each time to put back not only the power you took out when starting, which is quite a lot, but more to top it up.

Even with an alternator it needs some time to run at higher revs than tick over.

On my JBA Falcon, after a long run I disconnect the battery with a connection you can buy to fit the battery positive post. They are cheap to buy.

I simply lift one side of my bonnet and undo the knob. The battery will then stay charged up unless your battery is faulty.

Or if you don't mind, simply disconnect one side of the battery its-self after a long run.


yes you can, I always disconnect the battery cables when using it.


It won't hurt a thing. Go for it.


absolutely! i have customers with several classics, street rods, boats ,etc. and they swear by them.