Any experience with gel filled batteries?

[sueperdave]

Hi all.
My old 4 X 6volt house batteries were shot.  There is a local store here that sells used (less than a year old) gel batteries that are taken out of mobility scooters. 
They are gel filled instead of acid and are in good shape.  I assume they are changed for safety reasons.
I am not sure of the specs, but they are the size of an average car 12 volt.
These batteries are also 12v instead of 6v...not that this is an issue.

Anybody have any long term experience?
I am assuming they are top quality.
I was able to run on inverter power while watching tv and the exhaust fan on all night...they seem good so far.
They are on $20/piece.

 

[Gary RV_Wizard]

Are they really gel, or perhaps AGM? Somewhat similar characteristics, but different animals.

In any case, gel batteries make very good deep cycles and have zero maintenance. The only downside is that they are a bit sensitive to the charging system design, in terms of max voltage and rate.  You probably won't get as much life from them with your charging system as you would with one designed for gel, but for $20 each its hard to go wrong. The only real question is "how many amp hours?", or , alternatively, "how many RC minutes?".  Those are the standard measures of capacity.

 

[John From Detroit]

I will second what Gary said  and add this:

GEL batteries are very fussy eaters You have to be very very careful charging them, IN fact the very first 3 stage chargers were designed because of gel batteries.  I know, I've seen the designs.

Most places today use AGM's instead of GEL,  AGM has all the advantages of a GEL battery and none of the negatives (WHich is to say they are not at all fussy) Though they do appreciate a good 3 stage charger.  They can survive "Abuse" way better than a Gel, both physical and electrical abuse I might add.

For this reason the batteries used in mobility scooters are usually AGM .

Nothing wrong with AGM save the price of new ones.. If you got a good price GO-4-IT

One consideration with any battery is this: Starting or Deep cycle.. Deep cycle are best for "House" starting for chassis.

Mobility scooters, like golf cars, like deep cycle.. And AGM comes in that style too.

 

[sueperdave]

The 'stuff' inside has the consistency of Vaseline...maybe a little stiffer.

So far they have performed well.  Over night use, starting the genny etc...no complaints for a total of $80.

So how do they like to be charged...slow?

I am not going to modify the system anyway so it is kind of a moot point, but still curious.

 

[John From Detroit]

Yes very slow.. I would recommend you figure out who made 'em go to the maker's web page and get the proper re-charge specs from them.

It has been way too long since I worked with Gel batteries (like 40 years). Though I have done more recent research (like 2 years).

 

[John Canfield]

We had gel batteries on our last boat, they were the best battery at the time (late 80s-90s), however in my opinion AGM batteries are the latest and greatest.  I just replaced my seven year old Lifeline AGM house batteries this summer for a 'just because' reason.  I thought they might be a little long in the tooth at age seven (but they were still performing well.)

My new batteries are Lifeline AGMs but they have a higher capacity group 31 battery out now, the 31XT.  125 amp/hrs instead of 105 for the old version.

I would never consider buying used batteries.

 

[wstuart]

20 bucks each, what a deal.
And they seem to work for you too
go for it

cheers

 

[Gary RV_Wizard]

The 'stuff' inside has the consistency of Vaseline...maybe a little stiffer.

Definitely gel rather than AGM.

Gel batteries like to have lower charge and float voltages than standard flooded cell batteries. At usual battery temperatures in the 80-100 degree range, a typical gel battery should not be charged at more than about 13.5-13.8v and should float charge in the 13.2-13.5v range. The charger in your RV was designed for flooded cell batteries and almost surely exceeds that, likely charging at somewhere around 13.6-14.0v and floating at 13.6v.That will shorten the expected life somewhat.

But that's all largely academic.  You can't do anything about it without replacing the charger, and even then you probably won't find one that has a gel-charging profile as an option without pay BIG bucks. So enjoy your cheap batteries and let us know how it goes after a season of use..