AGM and Maintenance Free Batteries (1 Viewer)

[Brimal]

Question for you 12v and battery guru's.


Just taken delivery of our new wagon, another Adria 690SP.
I comes with a LEOCH Maintenance Free Sealed Lead Acid LPL12-100 (12v 100AH) AGM Technology.

Okay, great, supposed to be good batteries, heavy though at 32kg.

Anyway plan is to replace with 2 NUMAX CXV XV31MF110AH Maintenance Free Sealed batteries. Have had these on previous motorhomes and well satisfied, and no plans to change. So please no comments like try Varta or Banner or whatever.

On reading the owners user manual blurb, (well some of it), and it states:
The Transformer/rectifier is an NE237 “Battery selector switch: Setting the battery selector switch to the wrong position can damage the living area battery” (Yes okay understand and know that). Then “The option of switching over with the battery selector switch ensures optimum charging of the two battery types – lead gel or lead acid. (Again okay know and understand that).

Then next page is:
Living Area Battery – Danger –
Quote -The use of acid batteries as living area batteries in the vehicle is not allowed. Detonating gas can be created during the load process and lead to a gas explosion. The installation area is not equipped for accommodation of lead-acid battery Unquote

The two statements seem to contradict each other, anyone any ideas/opinions on this, as the way I look at it and they way I've always done is to put the controller on Lead-Acid and connect the 2 Numax, but the Danger bit got me to thinking, and am not always overly good on that sometimes.

Brian

PS Sorry to go on a bit but tried to explain the situation.

 

[meooo2012]

The battery supplied is lead acid isn't it?

I think the manufacturers are trying to cover themselves, even Land Rover recommend gel batteries for the defender (battery under the seat) but they always fit lead acid themselves.
Think they want you to play safe and avoid gas from an over charge situation, the battery compartment should be vented to outside for such an eventuality.

 

[Reallyretired]

I use the very batteries you are planning on using, they are good and a good price, but they do need venting if they are in the living area. (mine are in an outside locker) From the instructions it looks like the batteries are in the living area, hence the warning. Vent tubes are available on ebay which will fit in the vent hole on the side of the batteries, you just need to extend as necessary and get the other end outside, probably under the van.

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[jezport]

AGM sealed batteries don't require venting. Liquid Lead Acid batteries do

 

[andy63]

I would take those instructions to mean that they don't want you fitting any lead acid battery type that requires venting ..
Or if you did you would need to make provision for that..
That means fitting agm or gel .
Andy

 

[Mikeco]

I have two sealed batteries under the bed and they have been there for 5 years, they are not vented and do not require to be vented, in fact there are no holes to stick a tube in.

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[Brimal]

Thanks guys just as I thought on all those, nice to get some confirmation though.

 

[Lenny HB]

I think you instructions are aimed at the German market when I think vented wet cells are not allowed in habitation areas . Until recently German manufacturers fitted Gel batteries a lot of German manufacturers now fit AGM which are always vented but I think on the AGM's the vent is a safety vent and the battery will only vent under fault condition.

 

[tonyidle]

I think you instructions are aimed at the German market when I think vented wet cells are not allowed in habitation areas . Until recently German manufacturers fitted Gel batteries a lot of German manufacturers now fit AGM which are always vented but I think on the AGM's the vent is a safety vent and the battery will only vent under fault condition.

The same applies to gel batteries. They have vents that only operate due to a fault or incorrect charging.

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[Lenny HB]

The same applies to gel batteries. They have vents that only operate due to a fault or incorrect charging.

I'm aware of that but all the German manufacturers vent AGM's when they install them but they don't vent Gel's I can only assume AGM's are a higher risk of gassing through fault conditions.

 

[TheCaller]

They are all lead/acid batteries of one sort or another. Leaving aside any questions about suitability for purpose & concentrating purely on the safety aspect, the two questions are:
1. What happens to the acid if the casing is damaged?
2. How likely is the discharge of inflammable gas if overcharged?

Standard 'open cell' lead acid batteries don't fare well on either count. If the casing splits, liquid acid will run out. You don't want to be in the way. A certain amount of gassing, with the release of hydrogen from the top of the battery is pretty much normal behaviour & is why you need to top them up with water from time to time. Should be treated much like a gas bottle & be in an outside locker that is itself vented to the outside air.

Sealed 'maintenance free' batteries are no different as far as any damage is concerned. The acid will still flow out. They can still gas, but this should be avoided because there is no way to top them up, so careful charging is needed. Not really a problem with modern intelligent multi-stage chargers unless a fault develops. Because any gas now comes out of a vent tube, less locker ventilation is needed because the vent tube itself can be led straight to the outside. I wouldn't want this type under my seat while driving, which is a popular place for batteries in panel van conversions. The Numax referred to fall into this category.

AGMs have the acid absorbed onto a glass mat, so shouldn't leak wet acid if damaged. They only release gas under fault conditions. Usually fitted with a vent tube option, but not all converters utilise it. Generally considered safe anywhere in the habitation area, including under the driver's seat.

Gels have the acid in gel form. These are considered to be even safer than AGM if damaged. I believe all gel batteries are designed to reabsorb any hydrogen & oxygen produced back into the electrolyte, but I'm not an expert on the technology involved. As far as I know, no gel batteries have vent tubes fitted, although they do have pressure release valves so that if seriously abused, they would release gas in preference to exploding. The mutt's nuts from a purely safety point of view, although not suitable for every application. Not generally recommended for starting engines, for example.