Battery Charger for AGM

Dont like heat ? please explain then how my Fullriver AGMs under the bonnet of the landcruiser turbo diesel survive ,, AGMs were origanaly designed for military and space use , that AGMs cant stand heat is just a load of bovine droppings ,, any normally operating vehicle alternator WILL suffice to recharge an AGM ,, any voltage from 13.8 thru to 15.0 will suffice.

Alloy c/t - what sort of a response is that?

Why do people like you contribute (if you can call it that) if it is not constructive?

I had a Dynasty AGM swell so bad that it was almost impossible to remove from the battery tray (10 inches from the turbo) yet the other 4 in the camper are still going strong today.

It is obvious you know nothing about your AGM if you think it can be happily charged at 15V at 50°C (I checked the Fullriver spec sheet which tells you the charge rate). Yes AGM's were designed for the military but mainly because you can orientate them in any plane but also because you can put a bullet through them and they will still perform. You probably didn't know either that they shouldn't be paralleled with convential wet cell batteries due to the fact that they have different internal resistance and thus different voltage requirements.

As stated to Steve, I suggested getting the spec sheet to see what it states. Would you like me to send you one for yours?

Regards
David

My response shows that you know jack about AGMs in practice , following and believing the spec sheet on batteries is like believing a nissan 3lt patrol is a better vehicle than a 4.2. ,, who in their right mind would put any battery 10 inches from a turbo ,gel ,agm ,or wet cell ?? ,I run 3 x AGM HGL Fullriver under the bonnet of the 80series factory turbo ,never a problem in the last 36 mths ,use your spec sheet for its main purpose ,remember to burn it when finished.

I have downloaded the spec shhet for my DC96-12 and it says the initial charging voltage is 14.5-14.9V, that is very different from my Arlec which charges at 12.0v?? That is far greater than the o.2v.
Steve

Military Spec AGM batteries have metal cases to allow any excess heat to be conducted away to prevent thermal runaway.

AGMs are more prone to themal runaway than Gel or Wetcell because the electrolyte is not in ocntact with the outer case - unlike Gel or wetcell.

If your charge voltage is low enough and your Alternator is temperature compensated, you will not have a problem thermal runaway. If not, your AGM may die.

C'mon boys,
I guess it is comments like those above that confirm that wading through 6 hours of archives ends up in total confusion. There are so many varied products, experiences, applications and expectations that no one person will ever be be correct all the time.
Mainey, I originally had the Cruiser set up by an auto leccy that ran both batteries, charged the cranking battery first, then the aux but then both batteries were the same. I have only just changed over to the AGM. Are you indicating that my current set-up may not be appropriate? No, I don't run the fridge unless we are going away, and yes, I recently had to jump start the car cos it would'nt go. My cranking batery is fairly new, just needed a run.

Steve

Steve,
You say "I recently had to jump start the car cos it would'nt go.
My cranking batery is fairly new, just needed a run"

Can I suggest there is a problem if you run the vehicle only weekends and your 'as new' NZ70 Cranking battery won't hold enough charge to start the vehicle!!

No Steve, I'm not saying your charging set-up is inadequate - you implied that, because you had the flat battery.
If I had a battery that would not hold a charge for a fortnight I would be getting it back to a qualified person for expert advice, because when the warranty is 'out' it's your problem, not the retailers or the auto leccy's.

Maybe the battery is not being fully charged - for any number of reasons, making it a charging problem and not a battery problem.

Have it checked while still under warranty, because either the battery is faulty or possibly the charging system is faulty/inadequate.

If any 'as new' battery won't hold sufficient charge for a week or realistically even a fortnight it's a problem you don't need.

MC121045C..... 4500mA battery charger
12v Cranking battery - maximum 650 cca
12v Deep Cycle battery - maximum 80 a/h

Above are technical specs of battery charger mentioned,
note; it's NOT recommended for Cranking batteries over 650 cca.
Large diesel cranking batteries are often >700 cca's
Most effective Deep Cycle batteries are well in excess of 80 a/h

By comparison the "AC1000" is 6200mA which is ~40% more power and is therefore rated by the manufacturer as suitable for up to 800 cca batteries and 100 a/h DC's
However it will only charge to 14.2v so the final 'boost' charge is not available.
I believe the AC1000 is only about $100 and fully automatic.

Option (1)
If you NEED in excess of 14.2v and your alternator IS REGULATED to about 14.2v you will need a higher rated charger like the MC121045C

BUT...
what happens when you install the battery charged on the 'expensive' charger at about 15v into your vehicle, the battery will never be fully charged ever ever ever again, till you again recharge it with the 'expensive' charger as the vehicle alternator/regulator won't be able to maintain the higher required charge!!!
IF, as we have said above, the alternator IS regulated to only about 14.2v

Option (2)
The most probable scenario.

The vehicle alternator/regulator WILL charge in excess of 14.2v
therefore;
You can use the 6200mA (10a) battery charger to get the initial 14.2v charge back into the battery and install the battery into the vehicle, it WILL start the vehicle and the alternator/regulator WILL fully recharge it....when driven.
Note; the caps are there only for emphasis - not screaming L0L

Pedro,
I was having a discussion with a 12 volt specialist shop on the weekend regarding charging of my AGM and normal wet cell cranking battery and they informed me that I should never use a Arlec type charger on the AGM battery but they highly recomend the C-tek type smart charger as they considered them to be the best available. They had other battery chargers there but their opinion was that the C-tek is the best current technology.
I currently use a Protector 1600 battery maintainer which is grosly undersized for what I expect it to do but the car is only used on weekends too so the trickle charge is sufficient to top the batteries up.

Derek,

Please tell us your solution online as it's an often asked question.

Leroy

Hi Leroy

There are too many variables.

It would require another battery article.

Maybe time to write one on chargers.

AGM's require higher charge rates and good quality chargers. 4amps is too low.

Regards Derek.