Small 12 volt battery for TD

[Whuttitiz]

We saw somewhere on the forums about a small 12 volt battery that could be used for the TD. It was not a wet cell battery and had no lead in it. Does anyone have any information on this?

Thanks,

Denny

[daveesl77]

What kinds of things do you want to run? That determines the size battery you need. Don't just think of the bare minimum but also what you'd like to have.

dave

[Whuttitiz]

Not much in the way of lighting as they are all led. We would like to run our fantastic fan roof vent through the night though. It takes 3 amps to run it. We found what we think might work in the Braille M7 lithium battery. It's only 2.2 pounds. Just trying our best to cut down on weight.

[H.A.]

......

[GuitarPhotog]

3 amps times 8 hours = 24 AH. It all starts there. Add an amp hour or two to account for the LED lights, so maybe you need to provide 30 AH. With lead acid you shouldn't discharge below 50%, so if you were designing for a LA battery, you would need a 60 AH battery and the means to replace 30 AH
daily. That means running a 3A charger 10 hours every day.

Battery basics. The capacity calcs still apply with Lithium, but I don't know about discharge limits, or availability of smart lithium battery chargers that don't cost an arm and a leg.

[pohukai]

I use 12v drill batteries (3amp/hr). I could connect 4 in series for a big weekend, but 1 has been more than sufficient for the interior/porch lights and the computer fans for ventilation.

For my camping purposes, this has worked out excellent.

I can also connect a shore line to an old computer power supply and use the 12V rails for unlimited 12v power. I've NEVER used this when camping.

[Whuttitiz]

Thank you all for the input. Still a learning curve for us!

[GuitarPhotog]

I use 12v drill batteries (3amp/hr). I could connect 4 in series for a big weekend, but 1 has been more than sufficient for the interior/porch lights and the computer fans for ventilation.

For my camping purposes, this has worked out excellent.

I can also connect a shore line to an old computer power supply and use the 12V rails for unlimited 12v power. I've NEVER used this when camping.

No, you need to connect them in parallel. Connecting four 12 V batteries in series will produce 48 V, enough to burn out lots of things. Four 3 AH batteries in parallel is equal to one 12 AH battery.

Don't use a computer power supply to charge a battery, the voltage is too low and you will ruin your battery quickly.

<Chas>

[len19070]

I used one of these in a trailer years ago.

Hooked it up to a trickle Charger in the trailer so when I had electricity it would run all the time no matter what.

But without electricity All it did was 2 lights for 3-4 days and that was it. Battery lasted 2 years.

http://www.ebay.com/itm/CASIL-12V-7AH-C ... 43d73c7ca4

Not the best set up but it did work.

Happy Trails

Len

[pohukai]

No, you need to connect them in parallel.

Thanks... You're right and I do connect them in parallel. I completely disconnect the batteries if I'm using the power supply and do not charge the batteries with it.