Best Auxilliary Battery?

Hi Sand Man

The AGM type batteries, although more expensive, may be cheaper in the long run, since I probably wouldn't recharge a wet cell battery 'every 90 days' as seems to be recommended, so I wouldn't get much life from one.

Haven't found much online in the way of manufacturers with AGM batteries... better keep on searching!

Cheers, Max

The ACDelco was in the Trak Shak camper trailer when I bought it second hand 2 years ago. It could be anything up to 5 years old, but maybe not.

Unfortunately, I can't really say how long the Waeco will run on this battery, as I've been very haphazard in recharging it in the past... sometimes it's recharged daily by the 4wd, sometimes by a generator, etc. Have to improve my battery management habits!

At home, I've tended to let it recharge on the drive home, then check that it has a full charge (ie ~12.75V), and then done nothing further. The ACDelco has survived this for some years...

However, I've just recharged it, and although its showing 12.74V, the Indicator Window is showing Red (needs charge) when it should show Green (fully charged). I'm going to hook up a fluoro to it, as a sort of load test, and try to determine if the battery is still OK - but I strongly suspect not!

Since I don't want to be stuck with a dead battery in the desert (warm beer - yuk), I think I should get a new one, and keep the old one as a reserve, if it appears to carry a charge OK.

The Waeco 80L (CF-80) draws 5.5A when running (66W), and supposedly runs about 40% of the time. I'm tentatively allowing about 10 hrs per day of running. That's 55Ah per day.

Some battery sites seem to suggest that an AGM battery can be run down to 20%, but some other sites say this is nonsense, and suggest that you shouldn't deplete them to much less than 50% if you want them to last.

If that's the case, then I really need at least a 110Ah battery - and that's without allowing for any reserve. Worse, that only allows for 24 hrs without recharging.

The more I read about battieries, the more I get depressed!

Cheers, Max

"Some battery sites seem to suggest that an AGM battery can be run down to 20%, but some other sites say this is nonsense, and suggest that you shouldn't deplete them to much less than 50% if you want them to last. "
- some people have trouble moving forward. 50% was a good rule for wetcell Deepcycles, but AGM's are affected much less by deeper discharges. One camper trailer manufacturer recommends that the AGM batteries they install can be discharged to 20%.

Thanks Mike... being able to dscharge lower, without buggering up the battery, was one of the features of AGMs - I thought! Cheers, Max

Thanks Mike, will check these out.

Cheers, Max

Add "Firstpower" AGM DC batteries to that list, they are designed to be used as storage batteries, and charged by solar systems.
Priced at about $220 for 100a/h (10 hours, higher rating at 20 hours)

That's quite a good price! Thanks, Max.

Thanks Waddo, checking out his site now. Cheers, Max

G'day Derek

Could you advise brand, dimensions, terminal type, weight, warranty etc? And cost of freight to postcode 2446 (Beechwood, near Wauchope NSW).

Thanks, Max

Contact me on djbester@bigpond.net.au

Regards Derek.