Gel batteries

[Vintage465]

Hi.
I have acquired two used 135ah 12v gel batteries. They are 5”x18”. They were back batteries that were changed out after a years service. I think they really have no usage. My question is how will they work along side my existing 6v set up? Is there any specific charging instructions for this type batteries? If I can get them squeezed in somewhere on my rig should I hve their charging and usage separate from the 6v setup?

Thanks

[beemerphile1]

Vintage465 wrote:
This is a pic of the data on the battery.

Just pointing out, deep cycle batteries in RV use generally the ah rating is at 20 hours. The rating on the label is at 8 hours. Apples and oranges.

[Tom_M1]

Vintage465 wrote:
Yes, they are sealed lead acid as I noted in a reply to my post above.

AGM and gel are both sealed lead acid. They differ in the way that the acid is held in suspension.

[Vintage465]

SoundGuy wrote:

Vintage465 wrote:
This is a pic of the data on the battery.

So what you have are AGM Batteries, not GEL.

Yes, they are sealed lead acid as I noted in a reply to my post above.

[beemerphile1]

Vintage465 wrote:
Well, I'm finding out more about the batteries. They are Tellecom batteries, and are Sealed Lead Acid. I will load some photos of them in a bit. They are 116 pounds a piece!

Looks like AGM, not gel to me.

[MEXICOWANDERER]

Sound advice, LY

The rest voltage decay is by far the most important value that cannot be mismatched. But the decay should be measured after 10-days rest after being fully charged.

There are significant differences between a UPS model and automotive style AGM battery. Thicker mats, a significant percentage of calcium in both the positive and negative plates, and intercell connectors that are much less massive.

How does a person reconcile the charge needs between AGM and 2-3/4ths % antimony? They don't. And holding an AGM above 14.4 volts temp compensated for hours on end repeatedly is not feasible.

The batteries are going to constantly feud. Hatfields & McCoys.

Best choice is to rid the flooded batteries and pair automotive AGM with the Telecomms.

Not good sense to damage batteries needlessly. Flooded will draw the Telecomm batteries down almost immediately after cessation of charge and I believe forum members remember what happens to AGM batteries that never get fully recharged. This is one example where reality trumps E=MC2. I've done it and have seen the effects. If someone tried to give me a battery bank half flooded and half AGM I would not parallel them on a bet. The degradation is neither slow not subtle.

[landyacht318]

Not a surprise, 9 times out of 10 a 'gel' battery turns out to be an AGM instead.

I'd bring both upto 14.5v until amps tapered ot about 0.8a each, then let them rest and observe voltage as it settles.

If they are close in resting voltage, I'd have less fear of running them in parallel, but I doubt i'd parallel them with flooded gc-2's during discharge, and would want to top charge them separately.

When fully charged and rested I'd put a relatively high load on each separately, and time and measure voltage held during that load. If one is maintaining 12.53 where the other is 12.34v after the same load for same duration, I'd not use them in parallel for any long term duration.

But the worst that happens is they simply do not last very long. Just don't expect their full capacity when everything is paralleled, discharged then charged together.

Start by fully charging them, letting them rest, and then observing OCV.

[SoundGuy]

Vintage465 wrote:
This is a pic of the data on the battery.

So what you have are AGM Batteries, not GEL.

[Vintage465]

This is a pic of the data on the battery.

These are change outs from a com system back ups. For the most part they stay charged up the whole time and don't get drained. For my needs they might work out well due to their size configuration. As some of you may recall, I'm toying with the idea of having a separate circuit to run my propane/12v force air heater off. And before you suggest..........I won't run a generator except in a snowed in emergency. Since these would be pretty adaptable to fitting on the rear bumper(with some strengthening)and the heater is back yonder that way, it would make setting up a separate charging and heater circuit pretty easy. There is a master switch available to control the usage/charge delineation. I am thinking this system would stay completely isolated from the existing 6v X 2 system that powers the rest of the trailer except when traveling. I think the only real concern would be when I am buzzing down the road charging both sets of batteries off the tow vehicle. My thought is that as you're driving/charging, the weaker set of batteries wouldn't suck new life off the newer stronger batteries..........but I don't know that for sure though. My brother has been using these batteries solely on is vintage Ideal trailer for several years with great success. Though I must say he doesn't have to concern himself with a blower on his furnace as he had a non-force air Hydro-Flame furnace.

[Vintage465]

Well, I'm finding out more about the batteries. They are Tellecom batteries, and are Sealed Lead Acid. I will load some photos of them in a bit. They are 116 pounds a piece!

[time2roll]

Bring them along fully charged. Connect if the 6v pair is fading fast.

[beemerphile1]

You own the batteries, the match isn't good but use what you've got. The worst that can happen is a shorter battery life.

Those 135ah must be heavy batteries. I run used mobility scooter group 24 MK Battery gel batteries. Mine are only 74ah and they are 52 pounds each.

[MrWizard]

Gel batteries are getting rare

are you sure you don't mean AGM

there is a big difference

i have 135 Ahr AGM, batteries that were internet server backup battery trade outs

AGM's will work find parallel with your GC batteries, voltage specs are very close, AGM will with stand a higher voltage than your GC

GEL use lower voltage lower amp charge rate, and as stated "finicky and not a good match

[wa8yxm]

I would not worry about the unmatched in age, and they are most likely DEEP CYCLE but.. Gel batteries are not really a good choice because as batteries go they are very very "Finikey" they do not like a fast charge. They do not like OVER charge. they are more than willing to die at the drop of an excuse.

AGM's have many (All in fact) of the benefits of GEL. but they are the LEAST finikey.. Both tend to be expensive.

That said. If you add them .. In parallel since they are 12 volt batteries, with your existin pair of GC-2's the best advice I can give you is this;

If you have a programabble charger DO NOT INCREASE the basttery capacity setting, Take the slower charge instead.

After all FREE is a darn good price.

[Ed_Gee]

Vintage465 wrote:
Hi.
I have acquired two used 135ah 12v gel batteries. They are 5”x18”. They were back batteries that were changed out after a years service. I think they really have no usage. My question is how will they work along side my existing 6v set up? Is there any specific charging instructions for this type batteries? If I can get them squeezed in somewhere on my rig should I hve their charging and usage separate from the 6v setup?
C

Thanks

Not only are those batteries the wrong type and probably unmatched in age, but gel batteries require a slightly different charge voltage..... I would absolutely recommend you do NOT add these to your 6V wet cell battery bank....unless you don’t care about shortening the life of all of them ....