Dead Battery

[LowGear]

Hold on to your seat belts and shoulder straps.  A mower battery (about 6X8X8 inches) purchased from WalFart has failed after only three years.  OK, so that's not so bad but what I'm curious about is that the cell on the negative end of the battery was for all intents and purposes dry while the rest were setting pretty.  I've looked for cracks and moister but to no avail.  What's up?

Casey

[mobile_bob]

might be a short in that cell?
might not have been full when new?

i suspect we don't get much of a battery for ~25bucks these days

bob g

[Thob]

If one or more cells are shorted, then the OTHER cells will be overcharged by a standard charger, which will boil the electrolyte out.  Weakest cell goes dry first...

Lots of other things can go wrong.

[glort]

My luck has improved with batteries of late.
A few months ago while starting the lister with a large truck battery I bought cheap that was only 6 months old, the thing exploded sending bits of plastic into my arms and spraying me with acid.
My Daughter was sitting on the back verandah, heard the boom, looked up just in time to see me pull my wallet and phone out of my pockets and hurl myself  fully clothed into the swimming pool.

I'm convinced it was an internal short that did it as I later checked the terminals and they were on tight and the leads were long enough that it would be unlikley a spark at the motor would flash back along a path of gas and into the sealed type battery.

About 6 weeks ago while checking out the scrap metal bins at the local factories, I came across 3 batteries. One was in the skip at a truck repair place, and 2 others were dumped with rubbish on the side of the road.
Knowing I would be making a trip to the scrap yard soon and batteries get about $10 ea here, I though easy money to pick them up.
I got them home and put them on the battery charger for chits and giggles and 2 of them seemed to come up fine.  The other was cactus but still worth $10.

I was using them to start the lister when I was trying to balance it and they seemed to hold the charge and deliver the amps well and gave lots of spin up time.
A couple of weeks later, the battery in my wifes car died one morning after my daughter left the interior light on.  I have a couple of good large HD batteries but they wouldn't fit. I tried one of the roadside specials and it fit perfect and started the car several times.

I kind of forgot about the thing a few days later till I was at my dads wrecking yard last week and spotted his new battery load tester. Put in on the battery in the Mrs car and it came up to the batteries spec amperage which was a real surprise.
  Put it on the Doubled up batteries in my truck and it smoked the tester. Old fella said he hadn't ever seen that before.  :0)

So the roadside specials turned out to be OK.  I'm thinking maybe someone chucked the one in the wifes car thinking it was the battery when it was the alternator. I guess they would have found out soon enough and serves them right for dumping rubbish in the street.

For about the last 20 years I have always bought batteries from wreckers. Pay about $20 and the worst I ever had was one that only lasted a year. All the rest have been good for 3-4 so real bargains over buying new which would be $100-150 here.  I still only got around 3 years out of new Batteries.

Funny enough, most of the batteries the old man gets in his wrecking yard are stuffed. Being he only does Subaru's, they are also a bit on the small side for my liking. The originals would be perfect for a ride on mower, small motorcycle or a heavy duty flash light but not much else to my way of thinking. 

[LowGear]

OK, I remembered wrong.  I bought the battery in 2008 and paid dang near $27 for it.  The junk they sold then - can you believe?

Casey

[XYZER]

Casey,
Do they mow lawns in the winter there?
Dave

[vdubnut62]

  What winter?? And they have the nerve to act like they're roughing it, way out there on their own private paradise volcanic rockpile .
Ron

[LowGear]

Winter?

Is that a Finnish or a Russian word?  It doesn't sound Italian.

Casey

[Dualfuel]

Over the years working with junk batteries...I have seen plenty of cells right next to the negative terminal gone dry. Those lawn mower batteries can usually be brought back to life once with a desulfation and charge. The shorted ones that have a dead cell...charge them up, and whack the battery down squarely on something solid like an I-beam. Then charge again immediately. If you have broken off the shorted part, the charger's ammeter will show a steady increase. If no increase, whack again. Do it smart and hit squarely, if you hit at an angle it will crack and burn...
I think you can tell how great a man's fortune is by how he treats his batteries...when I couldn't afford new batteries..I brought mine junkers  into the house every night and put them by the stove. Trickle charging, desulfating, and constantly monitoring the Specific Gravity...now...if it doesn't start the truck, off it goes to Remy and a replacement.
BPJ

[glort]

Charging batteries sitting by a stove is a braver pastime than I would be willing to undertake and I don't consider myself a pussy by any standards.
I have had 3 batteries blow on me now over the years and it's something I'm pretty wary of.

There are things that will bring batteries back to life as it were but at the end of the day they are always well down on capacity and cranking amps. You might get " Extra life out of them but they will always still be a day to day proposition. Once they fail, the plates are always damaged or eroded and a long way from what they should be.

I drained and cut the top off a battery last week because I wanted the casing for something specific and when I pulled the plate assemble out, I was amazed how little was left. The Plates were less than a 1/4 of their original size and the battery was still holding charge so wasn't eroded unduly by neglect.  The sludge at the bottom was also impressive in that it hadn't shorted out the plates.

I took note as to the brand because they have obviously worked out the sulfation rate V's the erosion of the plates to keep them separated and from shorting.

I have also noted that one cell closest to a terminal is often dry when the rest are OK. I have noted it to be the positive one but no idea why. Maybe things are backwards down here like the way the water goes down the sink?   

I usually check the end cells first because in my experience, also they are the most likely to be low or dry on electrolyte. If they are OK, you can bet the rest will be.

[LowGear]

I went back to Walfart with my weekly allowance and while the shelf space is still there they have no plans to bring these batteries over to Hawaii any more.  NAPA wants $50 so I guess the local battery bandit will have to suffice Monday.  I can't see the crack but the white powder is now showing up on the engine compartment and that is not good even for my Electrolux mower - Gosh I like this machine.

Casey

[Randybee1]

I drained and cut the top off a battery last week because I wanted the casing for something specific and when I pulled the plate assemble out, I was amazed how little was left. The Plates were less than a 1/4 of their original size and the battery was still holding charge so wasn't eroded unduly by neglect.  The sludge at the bottom was also impressive in that it hadn't shorted out the plates.

How did you cut the top off?.. sounds like something I might want to do one day...

[glort]

Drained the acid, Gave the cells a wash out with the hose and then got a reciprocating saw and went around the casing just under the top lip.
I think you culd also get an angle Grinder and cut right around the top face as well depending on how the battery is constructed.

[Derb]

I usually find the automotive batteries give you one dozy start as a warning then next time around open circuit and all dash lights go out. Three years on average my batteries last but the wifes RAV4 battery expired last week and the battery on that was 6 years old and about the size of a mower battery as well .