12v LED Lights - Battery Advice

Joel,

I assume that you’d aim to leave home with a fully charged battery, and recharge it when you get home.

The details given by the LED seller are too scrambled to actually guess what current they draw, but I’d expect a little over 1 amp for the pair. Your shower probably draws about 2.5 amps. So on these assumptions, with 4 hours lighting per night (that’s 5 amphours) and say 20 minutes showering (more assumptions!!), you’ll need to supply about 6 amphours per day. For the week that’s about 40 amphours.


To allow the battery to have a long life, best not to discharge more than about 2/3, so a 60 Ah battery should last you a week and live a good long life. Larger the better of course, but bigger is heavier and usually costs more. An AGM battery is probably the best for this sort of use. It should not be left discharged longer than necessary, as all batteries deteriorate if left partially discharged. You will also need a charger – preferably a 3 (or more) stage one suitable for AGM batteries.


You might find parts of Electricity for Camping a useful read.


Cheers

John

Hi Joel

We have sort of similar issue and our camping style is minimal so we would never even take a second battery.
Since we now drive an auto we need a means to recharge battery in case of accidents and also power lights, stove, various battery chargers etc around camp.

Our solution was meant to cover all reasonable possibilites.

Basically we carry one of those 18AH gel cells in its own little alcove near back of the car.

Now you may think this isn't enough but trick is to make battery always charged without thinking about it and to use the battery by exception.

I.E. As far as possible we just use cars main battery for powering everything.

We keep a 10m 12vdc extension coord which tends to allow the cars battery to be used a lot of the time.

The gell cell battery has a 50amp anderson plug on it which can mate to one on the cars battery.
This solves the accidental discharge of main car battery problem.
It also has a cigarette ligther plug & socket on it.

The gel cell can be left at camp as required and only occupies 1/2 space of the jump start units.

Now trick is the more or less automatic charging of gell cell in such a way that it doesn't get overcharged.

To do this we put a 12vdc socket onto the cars accessories line near where the gell cell is stored and just plug it into the gell cel - which is its more or less permanent home.
Now this charging lead is fitted with a diode such that the gell cell is always being charged whenever the car is going or accessories are on.
When car is off, the gell cell and things it powers will never discharge the cars battery and overcharging is prevented by diode and length of wire to the gel cell.

Just getting a little more subtle the diode is a special type which effectively lets the gell cell reach its full charge (more details if interested).