Decca AGM batteries - from USA . QUESTIONS ON FITTING THESE BATTERIES

Caravan??? Mate- have you become a 'grey nomad'???

Willie,
what's the capacity of the original two old lead acid non sealed type "normal" batteries you presently use ??

Have you any tech spec for the two (new) AGM batteries ?


Fortunately, your Solar powered, so you will have no problems charging two large AGM batteries.

Hello Willie, with the charging most car alternators will charge that many batteries and that size.

A couple of things thou, car alternators have a duty cycle, what I mean is when they design a alternator it is olny designed to charge the main battery in the vehicle and as you increase the demand the longer it runs, the hotter it gets and then you start doing damage.

It may not happen in a couple of weeks or even a couple of years but it will happen.

I would not be overly concerned about what I said above.

The other thing is when they design a charging curcuit in a vehicle it is designed to only charge the battery between 70 to 85% full charge, this gets down to the main design critteria of the vehicle should start in X amount of times and there is no need to charge the battery 100% every time as the battery is ONLY there to start the vehicle it also gives a saftey margin in differant battery types and enviroments saving the battery from over charging and explosion.

The only way of testing a battery charge is by an electronic battery / load tester.

So your auxillary batterys will only get 70 to 85% charge off of the vehicle, the ideal way is to connect a smart charger and charge the batterys up to 100% charge before leaving home.

As newer vehicles start comming on the scene with there battery charging controlled by the engine ecu we will start to see more problems and heaaches.

I am sure alot of people will say that there vehicle charges there batterys to 100% and that they never had a problem, this may be true to a certian extent but it's how they designed it.

Regards Richard

Hi Willie, first off if your current batteries are working, why replace them.

If you want to know how there going, simply go and get them load tested, this is free and will indicate whether the batteries are still up to scratch and if so, if it ain’t don’t fix it.

Next, if you have managed to get 6 years out of a set of “normal” batteries, as you put it, if I were you, when ever you needed to replace them, I would fit the same batteries again because you are quiet obviously doing something right and if you keep doing it, you can save yourself a bundle.

Last but not least. One last word of warning, anybody who posts that an alternator can not fully charge ANY automotive battery, has not got a clue about battery use.

Cheers.

One of the biggest culprits in the misunderstanding of charging issues is the FAQ out out by www.batteryfaq.org/.

Quote:
"14.2. MYTH: Driving a car will fully recharge a battery.
False! There are a number of factors affecting a vehicle charging system's ability to recharge a battery, such as how much power and charging voltage from the alternator is diverted to the battery, how long the power is available, and the temperature. Generally, idling the engine or short stop-and-go trips during bad weather or at night will not fully recharge a car battery or will leave your battery undercharged which causes sulfation. When a dead battery needs to be recharged, it is best to use an external battery charger because you could overheat and damage your vehicle's charging system and your will save a lot of gas and wear and tear on your engine."

Now this is very badly written indeed and gives the impression that many people sprout on this and other forums.

You need to read the full statement in its entire context and then think about what it actually says.

What it does say that in certain conditions, e.g. stop/start trips during bad weather, or at night, will not fully charge a car battery and this makes sense when used withing the criteria stated.

What it doesn't say (but perhaps should) is that a partially discharged, but otherwise healthy battery, can obtain a full charge from the alternator if certain (normal) conditions are met.
These conditions are basically that the charging rate going into the battery need to be higher than that being drawn out of it by other devices and given sufficient time, a full charge can be expected. a wet cell battery will take longer than an AGM type battery as the AGM can (will) receive a higher charging rate.

It is indeed unfortunate when a URL site issues "misleading" information due to poorly written statements.

The gent that sold me the caravan , reckoned that the batteries must need changing as they could lose the plot out in the never never on the next trip .

Maybe I am a worry wart and should leave them until they finally die .

A big question still remains though . When I do change them to the Decca AGMs , how big can I get them - I mean what is the max amp hours I can get in the new batteries , that the three solar panels can charge successfully ?

Thanks ,

Willie .

Willie,

Why not ask this question on the New Bushtracker forum.

http://www.bushtrackerownersforum.com/viewforum.php?f=34

You will probably have Steve Gibbs reply to your query

Regards
RnR