Yet another battery question

Hey Tim

Thanks for that. Yeh i was told that my battery would run it all night but tried it recently and battery was dead flat in the morning. I did check it the night before and it was fully charged. I can't understand why i can't keep charge there so was trying to find an alternative:)
Dan

That sounds odd Dan. I have a 60AHr which is a tad small but even that it will run the fridge overnight (for one night). Maybe the battery is sus? or you loaded it up with warm beer and expected it all to be cold in the morning? or you left the lid off the fridge? or it was 40 deg. all night? or you had other stuff running off the battery? (just the obvious ones!)

Dunno mate, but you'll run the battery down quicker if you try running through an inverter! Maybe get the whole setup checked by a good Auto Electrician (including battery load test - not just voltage).

Sorry Dan, I just read your discussions with Derek (ABR) below - for some reason I'd assumed you were running a compressor fridge which should last a couple of days on a 105AHr battery (depending on conditions). Yes, the 3-way fridges use a lot of power on 12v so you might need to consider running from mains (240v powered site) or gas while stopped.

If you're planning to do a lot of car-based short-stay travel in remote areas (ie. no powered sites), I'd suggest a compressor driven fridge might be more suitable.

Yeh it is the CAb -55. ( oopps i think i called it a cab 50?). Gas line is all set to go for the next trip away. Just like to have that extra option though.

The inverter and associated losses will make power usage on 12V very similar.

I recommend you level the fridge and put it on gas when you stop. (Outside the vehicle)

Regards

Derek

Can you supply a website that supports the theory that an alternator won't fully charge a battery ??

Hi Gronk, cant supply a web site, but an electrical engineer, whom uses this site by the name of Colin sorry dont know last name, has several books out on the subject. After reading his science i bought a smart charger and experiented with my 4x4 set up. I found his knowledge so accurate i have been able to extend usable life from a standard batteries.
I have a 92 diesal patrol with a standard 55 amp alt charging 2 overlander batteries wired together with only a anderson plug to be manually controlled by me to fully charge both batteries, and all power to be taken from the factory fitted battery. The second battery gets used for nothing except starting if main is flattened, and if needed for longer periods of camping. I have a christy generator for longer periods of camping.
For science i put the smart charger on the twin battery set up and fully charge both batterys. I go for a drive remebering my vehicle has no computor or big power drain, except power windows. When i get home i put on smart charger and watch how long it takes to bring back battery to full charge, remebering power usage has been mainly starter drain. Now i figure with minamal power drain ie fridge and lights while camping the alt should have kept batterys fully charged. Wrong i found the smart charger 25 amps per hour takes about an hour plus to bring back the batteries to full charge.
I have used the manual battery set up for the past 25- 30 years and have never been let down with a flat battery. The best buy has been the chrsty generator.
Regards Col

I read the commercial pamphlet and don't agree with some of it. The grammer could also be improved - does it come from China ?

KK,
can I ask you what "some of it" you don't agree with ??

We can ALL learn by (you) asking questions
as they say: there's no such thing as a silly question

Maîneÿ . . .

The care and feeding of lead acid batteries gets very complicated as you know. What works on the laboratory bench does not always prove to be the same in the real world. Try a Google search on split charge diodes for some interesting points from a competitor. I would also like to see how they get around the heat problems when charging at high amperages as (in my opinion) that is the easiest way to damage the plates. It's a bit like tyre brands and tyre pressures and I would rather not get into an argument but simply say I have reservations about some of the claims being made regarding high current charging.

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