The lawn mower chewed up the 18 volt AC wire going to the driveway gate about a year ago and I just got around to fixing it.
Both batteries inside were new a year ago but both are dead as a doorknob.
I've had a 6amp 14-volt battery charger on them for two days and still, less than a volt (and no current on the gauge).
What does it take to resurrect sealed lead acid batteries? (Model RB500 & UT1270)
On Fri 29 Jul 2011 07:11:53p, SF Man told us...
The attention you should have given it a year ago. Duh!
Hi, Forget the batteries. They are toast. How about installing solar panel to trickle charge new batteries during day time.
A crowbar usually works. (You use it to open your wallet)
It's something I've heard many a time, and which appears true :-) But, just out of interest, what is it that actually fails in these types of batteries when they've been left idle for long periods?
cheers
Jules
Corrosion and sulfation, primarily. The plates of deeply discharged flooded-cell starter batteries can warp and short, as well.
The plates "harden" - the sulphate cannot be driven back out - and sometimes they get dead enough to actually freeze - or they dry out/swell. This is mostly from high temperatures, which means they would go bad even if they were being charged. Some brands are a lot worse than others for this kind of failure.
I'm curious also as 'normal' batteries can be resurrected (sometimes) even after a long period of disuse.
That 'would' have worked! The problem was my fault, for mowing over the barely buried wires; and, of course, for leaving the batteries off the charger for so long.
I just didn't realize these sealed 'dry' 7 amp 12 volt lead-acid batteries were so fragile.
I even tried putting 120 volts across the terminals with a jumper wire; but even that failed to resurrect the batteries. They've been on the trickle charger for days - and absolutely nothing. Not even heat!
The fact there's no current and no heat and no open-source voltage tells me they must have developed an 'open' somehow.
You're not kidding!
They seem to cost about $60!
GTO RB500 7 amp 12 volt battery = $29 + 10% tax + shipping:
me with 7.5 and 8 anp 12 volt batteries for $16.50 Canadian each plus tax.No shipping required.
or use 2 riding mower battery
What the hell do you mean "fragile?" You left the batteries out there for a YEAR, probably with a parasitic load on them from the gate electronics.
There is no lead acid battery that can be resurrected from being drawn completely down to 0 Volts, and held there for months.
Andy replies,
It depends on how bad the plates have sulfated. If you google the term "battery desulfator", you will learn about special battery chargers that use a pulsing high frequency charge to dissipate sulfate on the plates, and if the battery isn't too far gone, will restore it somewhat. These are not miracle devices, tho, and , in general, greatly lengthen the life of a lead acid battery PROVIDING it is being "nursed". It probably won't do your "ressurection", but is an interesting subject to learn about for future reference.
Andy in Eureka, Texas
i like the idea of a solar charger for this application
august 5th and google groups still broke last post august 1st.......
they suck.......
I believe the Firefly lead acid batteries would survive. Check out the technology on their site.
I doubt it. This guy's batteries probably got drawn down to 0 in the firts month or two. And sat dead from then till now. No lead acid battery is going to survive that.
There is quite a difference in the plate structure of the Firefly batteries compared to conventional lead acid batteries. I may Email the company with an inquiry about deep discharge of their product.
TDD
Deep discharge was not the problem. If you re-charge immediately after deep discharge, there is not much of a problem. Hoever if you wait several months, even a high quality battery is toast.
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