Solar panels...

I'd assume the alarm battery is probably a gel-cell battery (which is a form of lead acid)... retangular and sealed.

Deep cycle batteries are available in many types of lead acid, AGM and gel cell.

But this is NOT a deep cycle application, and it is actually the wrong use for a deep cycle battery (because there is no deep cycle!).

You really want a battery that does not develop problems from long periods of sitting on charge... and without a sophisticated charger, that really puts you in a pickle.

The right battery here is probably a lithium ion type, but now you need a fancy charger, that actually disconnects the charging current entirely.

The charging system you have here is one with a constant "float charge"... my suggestion would be a nickel cadmium battery, properly sized to handle the float charge given off (work for float charge current to be 1/6 of battery amp hour capacity)... nicads can handle constant float charge, nickle metal hydrides not as much and lithium ion not at all.

Greg
 
As they ( alarm batteries) are connected 24/7 to a trickle charger they never discharge, except if the power goes off. They last 3 -5 years before becoming unreliable.

These are more than man enough to power a few point motors and signal LEDs all day, and still not noticeably discharge, so the 24/7 trickle-charge solar panel can easily keep up. There is absolutely no need for the size or expense of a deep cycle type battery for this usage. The battery sits in a sealed weatherproof box underneath the track.

Power Sourse (2) (600 x 399).jpg

Errant battery now shows it is charging, and has a standing voltage of 11.4. I might be winning! :party:
 
That is indeed a gel cell, gelled electrolyte, lead acid chemistry.

I hate them, because they die just sitting there, not well suited for low discharge applications, but they are used because of the sealed nature, relatively high energy density, inexpensive, and can be used with cheap/unsophisticated chargers.

I don't have any old gel cells... I have 30 year old nicads...

The proof of your battery will be to see how much charge it stored... normally when gel cells go bad, you get sulphation of the internal plates, and you can achieve the right terminal voltage, but the stored energy is a fraction of what it should be...

The other issue is that clearly you are charging it with WAY more current than the solar cell will put out, which means while your battery charger might be able to raise the terminal voltage, the solar cell may not...

Good luck... (I have a special charger that uses high frequencies to desulphate batteries, works some of the time)

Greg
 
Greg, the whole point was to try and get away from such (expensive) sophistications.
 
Exactly, that is why I recommended a different battery, so you could use the same charger and a battery that lasted longer. (Also I believe you could use a cheaper, lower capacity battery)

Already you have added a much more expensive charger to the situation, to try to recover a damaged battery.

My last post was informing you that your recovery may not work, because you are "cheating" with much higher current... and the solar cell may not work...

My comment about a charger that can remove sulphation was just to be informative, a good all round 12v battery charger is owned by most households...or should be.. unless you don't have a car I guess.

Greg
 
After 60 something years connected to the motor trade and many thousands of lead acid batteries, I'm well aware that the recovery may well not be complete. However it may well do for a while, and a new battery for about £10 is considerably cheaper that the equivalent in Ni-cads, which granted, would be ideal.

The additional charger was readily available and amounts, again, to using what is to hand. A too heavy charge rate will often save the day, by breaking at least some of the sulphation, though left for too long could also buckle the plates.
 
These gel batteries are regularly changed by alarm service engineers - just ask one for some old batteries - typically 2 years old and perfectly servicable - and free.
 
stockers said:
These gel batteries are regularly changed by alarm service engineers - just ask one for some old batteries - typically 2 years old and perfectly servicable - and free.
Click to expand...

I have eight of them sitting in the hall at the moment..
These from Uninterruptable Power Supplies.. As has been said, quite often one fails, so the UPS reports a fault. New set ordered and fitted..
I have a smart 'recovery charger' some I can recover, some not. Would never use these cells 'in anger', except perhaps in a UPS here??
But to sit for a season outside, lighting a few buildings, with a Cheapy-Chinese charge controller, not a problem.

Oh, and alarm / computer techs store them up, and dob them in at the scrappy!
 
Our server farm has about 6 UPS systems each with 12 or so batteries. Whenever the system states the battery "pack" is not up to snuff, we replace all the batteries.

Funny thing, if I buy cheap batteries, maybe 25 to 50% are still serviceable... If I spend more and get quality batteries, normally it is 95% to 100% bad, i.e. they wear out before failing from defects, and the all wear very evenly. (usually 4 in series and then 3 or 4 sets of series in parallel)

Greg
 
For many years I used the gel batteries (4 x 12v in parallel) and the only problem, if you can call it that, was the tedium of recharging between shows. I still have a set for standby if I have shows over several consecutive days. My new (a first for me) solar panel seems to be doing its' job and I'm very happy with it.
 
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