Battery Series Powering GPS Device: Safe?

[Topper64]

I have a 36 Volt golf cart using 6 - 6 Volt batteries in series. If I add a circuit by connecting an automotive accessory plug to opposite poles of two adjacent batteries, will I get a 12 Volt circuit to be used to power a gps device, and is there any danger to the device?

 

[robert2734]

When the golf cart batteries are being recharged the external recharger will put ~8V across each battery so your GPS device will have to withstand an overvoltage of around ~16V. Nothing else jumps out at me. Does the gps device have a voltage regulator on the input?

 

[mayflow]

I have a 36 Volt golf cart using 6 - 6 Volt batteries in series. If I add a circuit by connecting an automotive accessory plug to opposite poles of two adjacent batteries, will I get a 12 Volt circuit to be used to power a gps device, and is there any danger to the device?

Your parallel circuit should create a 12 volt supply for your gps. I don't see where there should be any problems. Measure it with a dc voltmeter to be sure first. As long you have the 12 VDC the gps wants, it will only draw the current it needs.

 

[Topper64]

The GPS device is my Droid phone. The dc voltage measured 12 Volts. I put a fuse in the circuit and it kept blowing when I put the car cord in, so I was hesitant to plug in my phone. I checked with a friend who has several advanced EE degrees and he didn't think it would work. I told him I thought he was wrong and he asked me how many EE degrees I have. I told him none but that I still thought he was wrong. Not sure if he is still my friend. I think it is just a short in the accessory plug, which I will check next.

 

[Evil Bunny]

Your phone probably only wants 5V. If you're using the actual car charger cord in it's entirety, then it should be regulating the 12V input down to the 5V your phone is looking for. If you've modified your adapter in any way, you need to make sure you're not sending 12V straight to your phone.

blowing fuses without anything plugged into the other end of the car cord is most definitely not a good sign.

 

[robert2734]

Did you put the 12V across the fuse? Do you have the fuse in series with something else like a gps phone?

Just because the battery reads 12V when you measured it doesn't mean it will be 12V when the cart is running, or when the battery is discharged, or when it is recharging. But it is 12V when the fuse is blowing so this isn't your problem. If the phone is regulating the battery power in down to 5V, this isn't a problem.