[Boatanchors] GEL CELLS

[Ray, W4BYG]

In answer to the question below "is there any way to restore these..." 
and after years of being responsible for several hundred 12 v 7 A gel 
cells in our office and TV production system UPS's, I found that if they 
fell below 10.5 volts they would not restore to any useable life.  If 
that or below, we scrapped them.

In better quality commercial quality double conversion UPS's such as 
made by Staco, their charging circuits trickle charged very accurately 
and gave the best battery life.  Typically 5 to 7 years.  The consumer 
type switching UPS's such as made by APC were the worst, 3 years if we 
were lucky.
Ray, W4BYG


On 1/21/2015 4:05 PM, rbethman wrote:
> John,
>
> This is an issue with Gel Cell batteries in general.
>
> Even the "old fashioned" fluid electrolyte batteries would result in 
> very similar results over "several" years.  This was always especially 
> true if stored on a concrete floor.
>
> Gel Cell batteries "require" a small "float" charge to keep them 
> functional over an extended period.
>
> I have dealt with recent "pulls" from security systems myself, along 
> with a fair sized population of those in the Astronomy Hobby Community.
>
> This particular issue is brought up with regularity in that hobby and 
> its "Lists".
>
> I, along with others that keep these for portable use, swap the 
> batteries in and out of our Jump Start Packs that a lot of folks own 
> if for no other reason than to be able to jump start one of their 
> vehicles.
>
> This swapping batteries around allows us/me to run a trickle/float 
> charge on them to maintain them.
>
> Gel Cells come in more than one "flavor".  There are the "less" 
> expensive construction versions, and then there are the "more" 
> expensive construction versions.
>
> Poking around the "Web" I discovered that the ones that are used for 
> "good" Solar Energy Systems, meaning - "Worth Owning" - vs. "Marketed 
> Junk" - resulted in discovering the differences in the construction 
> versions.
>
> The Gel Cells that last the longest and provide the best service are 
> of the "Glass Mat" construction.
>
> This also means a higher acquisition cost.  So depending on one's 
> needs, one has to determine what they are willing to lay out for 
> acquisition.
>
> These used by Security Services, and for that matter, Telco outfits 
> such as Verizon that have pretty well forced their customers off 
> copper and on to their Fiber systems, use the "lower" investment Gel 
> Cells.
>
> I know that this issue exists with regard to my "gee whiz" fiber phone 
> line.  Therefore, I obtained an exact model number Gel Cell, and about 
> every quarter, I swap out the one they installed with the identical 
> one to cycle them and ensure that I will always have "one" 
> functional.  The main reason I did this is to ensure that even if the 
> power were to go out, which is why these fiber systems have a battery, 
> I will have twice the time-frame available to keep the phone line 
> active than what "they" say the battery is "supposed" to keep the line 
> functional.
>
> IOW, there really isn't anything that can be done to "restore" those 
> that have simply sat w/o attention.
>
> It really doesn't pay to simply pick up "pulls" unless you have a way 
> to cycle them through a trickle/float charge method.  The result is 
> what you have discovered from their sitting and waiting for use.
>
> I do keep a "spare" one for my jump start pack in terms of equivalent 
> ratings, yet that one is of the Glass Mat construction.  This jump 
> pack is always plugged into the wall, yet has lasted for over 5 years.
>
> The previous jump pack wasn't treated this way, and it didn't last 
> more than three years.  I learned the hard way.
>
> Regards,
> Bob - N0DGN
>
> On 1/21/2015 2:57 PM, John via Boatanchors wrote:
>> Greetings,
>>   Several years ago, I bought a case of gell cells at a hamfest.   
>> They  were
>> rated at 12V, 7A.   They were supposedly "recent pulls"  having full
>> capacity. Today I needed one as a replacement in a UPS unit and found 
>> that only
>> one was at full terminal voltage and would work in the UPS. Several 
>> others
>> were at 6V and the remainder essentially dead.
>>   Does anyone know of a safe way to restore these batteries or should 
>> I take
>> them to the recycle place?
>>   Thanks and 73,
>>     John,  W4AWM
>


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