Why won't my battery come back

[g1g]

I have a single coach battery i have used it off and on no problem. I keep a batteryminder on it when not in use and everything is great until I take it out and drain it down. Yes I admit it gets drained below 50% but the 4 times I have done this I was never able to bring it back to life, that means 4 different batteries. I remember when I was in the garage business I have has batteries totally dead and brought them back to life. I have even disconnected it and used several different chargers. If I use it just a little and do not drain it it is fine. Anyone have any idea what is going wrong?

[Davydd]

I had problems with batteries with my 2005 Pleasure-way Plateau using a 9100 series Progressive Dynamics converter until I added a Charge Wizard to it to regulate the charging while on the road and when it was plugged into shore power. The source of your problems could be the converter and you may be overcharging your battery.

[markopolo]

From all I've read if your battery goes below 10.5 volts (resting voltage) then in most cases it won't recover. That would mean that you took them down to 0% state of charge. So maybe check your equipment like Davydd mentioned. Check the voltage on the BatteryMinder also. You probably need to add a second battery so you don't end up discharging the single battery so much.

This recovery method for Optima AGM's might work on any type of battery because they say most chargers won't charge a dead battery.
http://www.optimabatteries.com/us/en/support/faqs/

How do I charge a deeply discharged battery?



If an OPTIMA battery is deeply discharged (below 10.5 volts), most basic chargers will not supply a charge. Also keep in mind that an OPTIMA battery will not recharge properly if treated as a regular flooded or gel battery. To charge the battery, you can wire a second fully charged automotive battery (12+volts) to the discharged AGM in parallel (+ to + and – to –). Then hook up the charger to the deeply discharged battery, setting the charger at 10 amps. Leave for two hours, monitoring frequently. During this process, if the discharged battery gets very hot or if it is venting (hissing sound from vents), then stop this process immediately. When the discharged battery reaches 10.5 volts or more, remove the standard battery and continue charging the AGM until fully charged.

For normal charging, a relatively low current, such as one or two amps, can work well, but when the battery has been deeply discharged, some sulfation of the battery plates may have occurred. If you charge at 10 amps, the higher current will help to break up this sulfation.

If you have an automatic charger, let it run until the charger indicates charging is complete. If you have a manual charger, you can get a rough estimate of the charging time in hours of a completely discharged battery (11.2 volts) by multiplying the capacity (amp hours or Ah) of the battery by 1.2. If your battery is not completely discharged, the time would be less.

In most cases these steps will recover an AGM battery. It’s OK for the AGM battery to get slightly warm during the charging process. If it’s hot to the touch, it means there’s a short and the process should be discontinued.

[booster]

As was said, most newer chargers won't charge a totally dead battery because they need some voltage to run themselves and start. You can do the parallel battery as shown or start the charge with an old manual charger for a few minutes to get some charge on the battery and then switch to a good charger.

If you are going by a monitor panel with the % lights on it for state of charge, you could be taking it totally dead without knowing it. The panels are notoriously inaccurate, so a good voltmeter is in order.

You don't say if it is wet or AGM. Wet batteries can often be recovered by using an equalizing charger or desulphating one. If it is a wet cell, get a hydrometer to check the specific gravity of all the cells to see what is really going on. Some AGMs can be equalized also (Lifeline) and they all can be desulphated.

If you have a decent, deep cycle, battery, taking it flat shouldn't immediately kill it, as long as it doesn't sit too long fully discharged.

[g1g]

Let me restate this I disconnected the battery and have tried 4 different chargers to try and bring it back. In fact the only one I didn't try was the one built into the van. One of them was a batteryminder hooked up in series? parallel? (I could never remember which term is which but I am getting 12 V pos to pos -neg to neg) with another battery so it was actually connected to 2 batteries. another chargers is a basic 30A power supply another 10A charger and also a small 2 A charger. They were all lead acid batteies 2 sealed 2 not sealed. My latest was the sealed so I cannot use a hydrometer. I have even left the 10A charger on it for several days and there is no more charge than when I started. I used a battery load tester on it and as soon as I pull the switch it drops down to couple volts. Also I almost forgot that I never had to add water to any of the batteries that I had left on the batteryminder and it is charging more than the coach battery.

[stanw909]

I have to admit that I have twice drained my Optima blue down to nothing since buying it in May.I have a very old (35 yrs?) Schumacher deep cycle charger that I inherited from my Mom and dad.It has brought the battery back both times with no problem other than the stress on the battery.Is it because my charger is so old that it doesn't know any better?

[markopolo]

Originally Posted by g1g

................................ I am getting 12 V pos to pos -neg to neg) with another battery so it was actually connected to 2 batteries. .......................

Was it
1. two actual batteries (in parallel) or
2. one battery with two chargers or
3. two batteries but with the isolator in between them

[g1g]

Originally Posted by markopolo

Was it
1. two actual batteries (in parallel) or
2. one battery with two chargers or
3. two batteries but with the isolator in between them

I have a single battery but I hooked up another good battery with jumper cables and I put a battery charger on it all day as well as leaving a batteryminder on it for a few days. I figured the new battery would provide enough power for batteryminder to do it's charging. All said and done neither charger did anything for the battery. After a couple days I checked the voltage and it was only a couple volts. (I disconnected jumper cables when I disconnected the charger)

[markopolo]

We're probably alike in that we don't give up on something easily

I wonder if the second charger sees the 13 volts (or so) from the BatteryMinder and thinks the batteries are ok.
Do you know if your other charger's output is at least 14.4 volts when trying to bring that battery back to life?

http://www.ibslhc.com/battery-care/char ... ging-faq-s

Batteries below 11.50 volts require longer recharge times (20 hours) and often require special charging techniques. Voltage readings this low are often an indication of internal damage and usually requires replacement. At the very least, these batteries have very high internal resistance and can require higher voltage and special equipment to overcome the high resistance. Use care when attempting to recharge low-voltage batteries. Batteries that gas heavily and emit a strong odor are most likely damaged.

Is the battery still under warranty? If not, maybe it's worth calling a few garages to see if they have any special chargers to try to bring it back. It would probably have lost some capacity though.