Has anyone had any luck with the battery desulfinators to make car batteries not in use live longer? I've that feature in my fancy Vector 40A battery charger and I've tried running it for up to 5 days continuously to maybe make my batteries live longer during periods of little use, but it's never done much of anything as far as I can tell.

I've made one that to work.............

They won't help if you have any shorted cells.

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Thanks. Just what kind of pulsing did you use and how long running it to see any improvement?

Out of town so I don't have my links to a DIY site...

Needs days to weeks depending on battery size and how bad off the battery is.

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Northern tools has them on sale right now. www.northerntool.com Search for "battery minder". The most versatile unit runs ~$100 (on sale for ~$90?); it handles flooded, gel and AGM (Optima) battery types, and is selectable for 2,4 or 8 amps. Its also useful to have a cheap dumb charger to put an initial charge into a dead battery. The Battery Minder won't cycle if the battery is totally dead. You'll also need a decent glass float-type hydrometer to monitor the process. I've desulfated/rejuvinated close to 50 batteries over the past few years. The product does work as advertised. The smaller wall wart Battery Minder (~$50) is fne for a lawn tractor battery or winter storage charging of a car battery; it only outputs 0.75 amp.

My fleet is mostly Mopars that use Group 24 or 27 batteries, and I have some spares. About twice a year I cycle each battery through desulfation for about 2 weeks. My oldest battery is a 1996 Delco that still passes carbon pile load test.

Ken

Thanks; that's impressive to have a battery last that long. The length of life I got from my mine seems to very randomly; low of 2 years, high of 10+. (That last one behaved very oddly when it failed; one day it would output 15A fine, but not accept virtually no (<5mA) current.)

I followed my big Vector battery charger instructions and put my batteries on desulfination 1-2x/yr for 1-2 days; never seemed to make any difference in the lifetime. When they acted up, a week or 2 on the Vector desulfation never seem to accomplish anything.

I've been running the Harbor Freight inexpensive ($4-$15) regulated float chargers (#42292) for years; I just had 3 fail - their voltage output dropped below the spec - but when working put out the right voltage with much more current capability than I'd ever use for float (~0.5A max? I measured it, but now I forget exactly what it was).

I've taken them apart and they have a tiny current & voltage regulated DC supply. They have no desulfination feature; I'll have to look into the Battery Minder to see what's it's got inside that my fancy expensive Vector doesn't. Thanks again!

The Battery Minder contains a very efficient switching power supply that's controlled by a PLC. It really is a "smart" device. There's not much to see inside the case. Opening the case will void the warranty btw.

btw I have a 2002 Group 27 battery that I used in my plow truck. It sat for most of the spring/summer/fall over the years and went dead several times. Two years ago it had three cells with very low S.G. and failed load test. I've kept it on the Battery Minder whenever I wasn't processing other batteries. As of today it has two cells that are only marginally low, and the other four are equal. And it passes carbon pile load test!

Ken

The number one killer of batteries is heat. Number two is failing to keep them at full charge. As the lead sulfate forms, it occupies more volume than the original plate. This compresses the plates until they short-circuit and fail. You'll notice that an old failing/dead battery will have the ends of the case bulging outward. If its a significant bulge, desulfating will not work. I have a friend who rents cars for movies. The cars mostly sit in the lot. I've been ~80% successful in restoring his batteries, even when they present as "dead", so long as the case does not have a significant bulge.
It requires much more than 1-2 days. I process mine for 1-2 weeks minimum, at 8 amps. The Battery Minder generates a sweep of frequencies that does a much better job of breaking up the lead sulfate than other desulfaters that only operate at a single frequency. If the battery has removable caps, you need to monitor the S.G. every few days; when you see no more improvement, its as good as it will get. A badly sulfated battery will require many weeks of desulfation.

Ken

http://home.comcast.net/~ddenhardt20126 ... desulf.htm

http://leadacidbatterydesulfation.yuku.com/

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I use a solution on any battery that can be opened. This helps the process a great deal. It helps to keep the process from happening in the first place. Ill try and find the bottle and let you know what it is.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered