Can I hire someone to build a current limiter charger for me

[John]

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

 

[John Fields]

On Thu, 2 Dec 2010 17:23:47 -0800 (PST), John <intellisig@gmail.com>
wrote:

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.

---
How much are you willing to spend?

---
JF

 

On Fri, 03 Dec 2010 10:19:29 -0600, John Fields
<jfields@austininstruments.com> wrote:

On Thu, 2 Dec 2010 17:23:47 -0800 (PST), John <intellisig@gmail.com
wrote:

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.

---
How much are you willing to spend?

---
JF

Depending on the year and make of vehicle, there may not be power at
the lighter receptacle unless the key is on.

Proper charging will require some intelligence in the "box" between
the lighter receptacle and the Optima battery. I'll give a ball park
price for a one-off unit as $120US - but only because I've already
done the research on another battery charger project. You're paying
for design, testing, board creation, and parts.

Or you can research "boost converter" and "constant current source"
and see if you find something online.

John