View Full Version : AGM versus Lead acid Deep cycle

25-07-2007, 04:19 PM
I am totally confused. I take delivery on Friday of my GXL D4D, i am planning to install a dual battery. I was set, after much research to install a AGM battery, I phoned the supplier today and he said he would not recommend it because the high rate of recharge may cause the AGM to overheat and explode....all the research I have done says AGMs are the go. Does anybody have experience with AGM as dual batteries off a prado alternator, if so did they explode and if not how long did they last.

25-07-2007, 04:51 PM
No expert but I also did my research before buying a second battery for the Prado.

The consensus is that AGM's are a bit iffy under the bonnet, and as a matter of interest the largest one that can be installed (height wise) is a 90 amp.

Have previously used AGM in back of old 80 series and was wrapped .
Have bought a 120amp Fullriver AGM and a Flyer (Battery box from ABR -http://www.sidewinder.com.au/page18a.html).

I purchased battery from http://www.fridge-and-solar.net/ and the site has some excellent articles and you will note the AGM's charge very quickly and retain their charge.
Well worth reading the articles and Mr Val knows his stuff and has been a big help to me over the last few years.

Am having the wiring installed at the moment and it should be ready by the weekend.
Set up will be such that battery can be removed if not needed and in fact my Waeco can be run from cranking battery while travelling and it is turned off when I switch motor off.


26-07-2007, 12:52 PM
I've had AGM batteries (starter and auxilliary) in the engine bay of my petrol 95 series for years without any problems.

One is an odyssey brand battery, and the other is a full-river DC series battery (90ah). Never had any problems, the aux battery gets pulled down low sometimes if camped in one spot for a few days without driving, but is always fully recharged (from the standard prado alternator, via a basic redarc isolator) within an hour or so of driving. They recharge quick, and don't mind being drawn down. That's what sold me on them.

I'm no technical expert, but I can only say I've had no issues with under bonnet temps causing any issues at all.

27-07-2007, 01:48 PM
Thanks for the replys, thats exactly what i thought. The guy who warned me off them wasn't totally up on the mechanics of these batteries. If they produce extra gas because of high recharge current they valve regulate the gas internally, this means they get pressure build up. If you read the specs of these batteries they are designed to take a high recharge current.

Thanks again.