Hi,
I have an Optima AGM battery in the trunk of my car. I have a 12 watt solar panel in the back deck of the car to keep it charged. I use the battery to run various electronic devices while the car is turned off.
The problem is that in the winter I don't get enough sun to keep the battery charged. So about once a week I have to connect an AC charger to charge the battery. I charge it at no more than 1 amp as the Optima can take 1 amp indefinitely. The charger I use is smart and even though it's only supplying one amp, it still will turn off after the battery is charged.
What I want is a cable/box I can connect to my car's cig lighter and put 1 amp of charge into the Optima battery while the car is running. I don't want to have to connect/disconnect this cable: I want to leave it connected all the time. So when the car is turned off the cable can't allow the battery to discharge through the cig lighter.
Do you know of a commercial product that can do this? I bought a Black & Decker car to car battery charger thinking it might be a good solution. I ended up not using it because it pushes 5 amps into the battery. It blew the fuse I have on the battery and I really don't want to push 5 amps into the battery. If you know of some other commercial product that does what I need, please tell me.
I suspect this is very easy to build, but I don't have the time to figure it out and build it. I'd like to pay someone who is able to design/build this.
Do you have any advice how I can find someone who will build this inexpensively? How can I find some Electrical Engineering student in China who can build this super cheap? I'll buy two. One to use and one to have as a backup.
Thanks! John