WirthCo 20308 Battery Doctor Top Mount Compact Battery Switch without Fused Bypass

This thing works great. Simple to install, simple to use. Build quality A+. Use this if you park your car for a week or more without turning it on. Storage and long term parking in an airport come to mind. Not only does it kill battery drain with normal on/off, the whole knob can come off which makes your vehicle theft proof. If your vehicle has an electronic key, make sure the windows are up and the doors are open before you turn off the battery. Your doors will lock automatically when electricity stops being sent to them and you will be locked out of your car. This happened to me and I had to call AAA to get me back in. Close your doors after the battery is turned off. If you remove the knob entirely for anti theft, throw it in the glove box until you need to reinstall. The chances of a thief figuring out how to reactivate your vehicle is less than zero.

Perfect. This is my second - I've had the other for 3 years. If you have a car that you might leave non running for a week or more at a time - this can save your $100 or $200 battery like it did for me. I got tired of killing DieHard batteries - they were under warranty but I felt bad for the store. Those newer gel batteries are not meant for deep discharge - you can't run them all the way down like a trolling battery on a fishing rowboat. The electronics in a car might run the battery out after a week or two of the car sitting around. Recently my truck battery went dead. The warranty was for 6 more years on this gel DieHard, but guess what - Sears near me closed down. So Costco's best battery - with 4 year warranty - was just under $100, and I think it's the same battery. When I installed it, I noticed the interior cabin light lit up in the truck. What the hell? Did I leave that thing on accidentally. So I bought one of these for the truck, and now, no worries.

I have a vintage car that likes to drain the battery. After adding the switch, I was able to cut the drainage with a twist of the switch instead of disconnecting the cable. Very useful product and now I know my battery is ready to go when I need it.

I have some kind of electrical drain in my truck which would pull the battery down to zero in a few days if not constantly driven - especially in cold weather. It was never intended to be a permanent installation just a stop gap until I found the electrical drain. But, I'm leaving it installed. It's very easy to install and use, deters theft, and allows quick connection of a battery charger while isolating the battery from the rest of the electrical system.I tried other switches but had trouble mounting them in the crowded engine compartment of the F-250. If I'd tried this first, my problem would have been solved in five minutes. I'll still haven't traced down that electrical problem - it's not much of a problem any more. Highly recommended.

I'm returning this. It looked good online and I hoped this brand was better than the cheaper versions for sale, but this design has some similar big flaws. Similar to other cheaper versions, the whole thing separates when the knob is unscrewed. Only the knob screw holds the two conducting parts and the insulator together. I think the electrical contact surfaces are too small, and the machining isn't great so there isn't great contact. I don't trust it for my car. I'll get something heavier duty designed for boats.

It's just a simple switch, what could go wrong? Made in China - says it all. It actually didn't work! How is that possible, you say? Because the bottom of the screw knob has to come in contact with the top plate in order to complete the connection. This unit was not manufactured properly. The bottom of the screw did not project below the plastic casting of the green knob. It was necessary to file away excessive plastic in order to maintain contact. A switch like this cannot be allowed to operate inconsistently. Depending on your particular vehicle, it will permanently damage your alternator tf it disconnects while the engine is running.

because of limited space, difficult to install in ford 2000 e150 van. male stud on device a little small in dia. made it hard to clamp onto by vehicles negative terminal cable.disconnect and reconnect is simple enough (don't remove white plastic insulator).however, not obvious how many turns are necessary to disconnect - too many (as i did) and device comes apart.

My car has been sitting for a while as I'm not traveling for work, doing very limited grocery runs, etc etc. I'd come back to it after a week or two and the battery would be dead. The hassle of getting a jump to go to the store was really tiresome after the third time...Enter this little beauty.Easy to install on my Honda Fit. So very easy to use. And absolutely no issues since.Saves you time, money, annoyance. Worth it.