oldpilgrim
Elite Member
How old is the battery?
battery wont hold a charge
- Thread starter billb7984
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PhysAssist
Elite Member
- Joined
- Aug 22, 2011
- Messages
- 2,635
- Tractor
- Kubota B2320
dickfoster
Elite Member
Yes and no some chargers have desulphation built in but not all. Typically the high end stuff and some smaller chargers that you can use as a tender charger. A tender charger is intended to maintain battery charge not recharge a totally dead battery.
I have a power supply that I use to specifically tailor the charge current voltage to the type of battery, a standard 20A charger with deep cycle and standard wet cell settings that I use to recharge a dead battery and a small two amp desulphator to recover sulphated batteries. If the battery shows signs of sulphation, won't hold a charge, after an initial charge, I put the small 2A desulphator on it and forget about it for a few weeks.
For a couple of spare batteries I have some small float chargers, so they are ready to go with a full charge all the time. I use them for occasional, welding etc.
Here's an example of chargers used to charge AGM batteries that have desulphation pulsing circuits built in. http://www.odysseybattery.com/documents/ody_chargers_sheet.pdf
Note; you choose the charge amperage based on the capacity of the battery. AGMs like to see a pretty stiff initial charge current, hence the sizing. These chargers would likely damage a traditional wet cell by over charging or cooking it dry. While prolonged and repeated use of a charger made for wet cell types would likely lead to a sulphated AGM battery, although one with a deep cycle setting can be used for to recharge an AGM, it just won't be optimal.
Here's an example of a small 1.5 amp desulphator like the 2 amp unit I leave plugged into my truck when it's in the garage. Amazon.com: BatteryMINDer Model 1510: 12Volt 1.5 Amp Maintenance Charger/Desulfator: Automotive
If it's parked outside and idle for a long time, I have a built in solar panel built that holds the batteries up so I don't need to worry about it.
dickfoster
Elite Member
It doesn't really matter. The leading cause of battery failure is sulphation and batteries that seem beyond all hope can often be recovered with a desulfator. Not always but often. If you've got the time, a small one can often recover a seemly done battery and pay for itself the first time out. It does take time though.
msb1766
Platinum Member
I bought one of these battery/charging system tester, work great.
Amazon.com: SOLAR BA9 40-1200 CCA Digital Battery and System Tester: Automotive
Amazon.com: SOLAR BA9 40-1200 CCA Digital Battery and System Tester: Automotive
MT2501owner
New Member
You can also check to see if there is a load on the battery when the key is off by putting a small 12v light bulb type tester inline with the positive battery cable and seeing if you have current (light will glow). If you do, pull fuses or plugs until the light stops glowing. The circuit you disconnect that turns the light off is shorted.
buickanddeere
Super Member
With some tinkering a sulphated battery may have some capacity restored . However the battery will never have full rated CCA or AMP hour reserve . After being sulphated , multiple deep cycled or being run 100% dead flat even just once. The flooded lead acid battery just does not fully recover.
k0ua
Epic Contributor
Agreed. I have recovered dead batteries before, but the capacity of the battery is not as good.
aczlan
Good Morning
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- Kubota L3830GST, B7500HST, BX2660. Formerly: Case 480F LL, David Brown 880UE
Yep. But for a $400 set of forklift batteries that just get used around the shop, its well worth it for me.
Aaron Z
k0ua
Epic Contributor
No doubt.