Re: Current Draw, Charging batteries

On 10 May 2007 11:21:20 -0700, in sci.electronics.design John
<ewsnet@xxxxxxxxx> wrote:

Ohm's law is in here somewhere, but I don't know quite how to apply
it....

I use a deep cycle battery, ~80AH @ 5hr rate.

I would like to tote it along on trips, but it needs to be somewhat
portable, so I am looking to wire up something in the trunk, or back
of my truck, to juice it up when I am driving.

Where I get lost is, if I the battery is basically fully discharged,
how do I know what size wire I need to use, to get it back up to
snuff? Do I need some sort of control ckt?

It would be great if I could just plug it into the cigarette lighter,
but that is fused at 10A, so I am assuming a deeply discharged battery
of that size, would pop the fuse. Right? Same thing for a 14Awg set of
connections, they would overload on a dead battery?

Don't really want to run 8Awg wire to the bed, or the trunk, so how do
I figure out what the max current is, that a "dead" battery of this
type, will draw, so I can keep it simple?

I know there are other issues, like safety, starting the vehicle
first, and then connecting the battery, and such, but the basic
charging issue is where I would like to get some advice, please.

Thanks a lot,

John
First, it is Really Bad to fully discharge a battery.

Try here for more info http://www.batteryuniversity.com/
This should answer many questions


martin
.

Relevant Pages

  • Re: OT: Outboard Motor Charging System.
    ... A large portion of the problems with the battery CD units are caused by ... Blue: +12V ignition switch ... Check the voltage on the blue wire at the CD unit. ... Disconnect the white and blue kill wires from the CD and connect a DC ...
    (rec.crafts.metalworking)
  • Re: Battery drain
    ... In my 2000 Sea Ray 185, the thin red fused wire from the ... battery is for the amfm radio memory. ... But still, I would think that even with a bad battery, your volt guage ... an old rule of thumb is a decent charge when running is your alternator ...
    (rec.boats)
  • Re: converter diagnosed
    ... BTW, did you have to run a new, larger, wire to the battery from your ... Any voltage drop through the wiring detracts from the ... Suppose the converter is regulating to 14.2 during the absorption stage. ...
    (rec.outdoors.rv-travel)
  • Re: hu connection help
    ... Wiring your amplifier directly to the battery should be fine - just ... connected with AT LEAST as thick a wire as your positive wire and as Lull ... I suppose I should point out that unless the amp is litterally ... once the car is running you will be getting ALL your power from your ...
    (rec.audio.car)
  • Re: Battery drain
    ... you may have gotten a bogus battery. ... But still, I would think that even with a bad battery, your volt guage ... I'd say you need to take the alternator to a competent shop and have it ... wire that is attached to any switchable source. ...
    (rec.boats)