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Solask · 01-25-2015, 10:41 AM

2012 allegro with two 6 volt deep cycle house batteries. Took it out of cold storage to head south tomorrow.
Right out of storage batteries were at 12.3 volts but I noticed water level was almost below the cells. After driving and or running genny for several hours, I topped off the batteries with distilled water, covering cells but not to the top of the vent openings.
Ran genny for about two hours, turned off and left the coach over night with only the fridge running. By noon today the batteries were at 9.9 volts... What happened? Batteries have never run dry or been abused in any way..
Did adding water require that I get a 10 or more hour charge on them?

450Donn · 01-25-2015, 10:43 AM

Replace them. Time is not on your side. It is possible that the terminals are corroded, but more than likely age has finally cought up to them. If you really want proof, take them out, charge them fully and have them load tested.

Sky_Boss · 01-25-2015, 10:55 AM

Quote:

Originally Posted by 450Donn

Replace them. Time is not on your side. It is possible that the terminals are corroded, but more than likely age has finally cought up to them. If you really want proof, take them out, charge them fully and have them load tested.

3-4 years isn't very old.

Now...what I think I see in the post was not checking water before charging. I would be concerned that applying a charge to a relatively dry battery would hasten it's demise.

However, did the OP verify the charger was working properly? That would be something I would look into also. Been there, seen that.

wa8yxm · 01-25-2015, 10:57 AM

Well, for starters you said:
I refilled them but not to the TOP of the vent openings.

THAT IS TOO FULL

The proper level is 1/8 to 1/4 inch BELOW the bottom of the filler tube or split ring (As it is also called) you should have NO liquid in the tube itself.

And it is very likely that they sufered over the winter and are toast, but not from the over fill, from other reasons such as old age.

dennis45 · 01-25-2015, 10:59 AM

Your batteries are only two years old. Unless you ran them dry, left them in a state of discharge and or froze them, they should be OK.
I would start with a voltmeter and check the voltage at the batteries when plugged in to shore power to see if the converter is working.
Then with shore unplugged and engine running, do the same check to confirm the alternator is charging the batteries. With the engine running, check both the house and chassis battery voltage.
In all cases, you should see in the range of 13.6 - 14.2 VDC. If you see all charging systems are working, the batteries are likely shot but before you replace them, have them load tested.
Note, corroded terminal connections will cause problems also. Make sure they are all clean and tight or they will not be able to receive charge voltage.

Solask · 01-25-2015, 11:10 AM

Batteries being shot are not likely... They are two years old and as I've said, have suffered no abuse..
The water level was just at the top of the cells, give or take 1/8th inch. Nothing serious I would think.
They were nearly fully charged right out of storage and cranked the genny no problem..
After adding water to JUST BELOW THE BOTTOM OF THE FILL TUBES, I have dead batteries...

The charging system on the coach is working fine with either the engine or genny applying 14.4 volts to the batteries..
AGAIN, while I can't find anything conclusive on line, do I need a longer period of charge after adding water? Why would the batteries be dead after servicing them correctly?

dennis45 · 01-25-2015, 11:29 AM

Quote:

Originally Posted by Rkh

Batteries being shot are not likely... They are two years old and as I've said, have suffered no abuse..
The water level was just at the top of the cells, give or take 1/8th inch. Nothing serious I would think.
They were nearly fully charged right out of storage and cranked the genny no problem..
After adding water to JUST BELOW THE BOTTOM OF THE FILL TUBES, I have dead batteries...

The charging system on the coach is working fine with either the engine or genny applying 14.4 volts to the batteries..
AGAIN, while I can't find anything conclusive on line, do I need a longer period of charge after adding water? Why would the batteries be dead after servicing them correctly?

When you add distilled water to the cells, you are diluting the electrolyte. (Lowering the specific gravity) By charging, you are driving the sulphur from the lead plates back into the electrolyte until the battery reaches full charge specific gravity. This takes time.
Now, if you see a charge rate of 14+ VDC for say 8 hours, it is likely an indication the batteries will no longer accept a charge and are in fact toast.
Most OEM batteries are not of the highest quality will not last as long as some others such as Trojan etc but they should, with decent care, last for at least 5-6 years or longer.

dennis45 · 01-25-2015, 11:35 AM

Here is a link to some good info on battery maintenance. Check the part about adding water and cleaning.

Battery Maintenance | Trojan Battery Company

Solask · 01-25-2015, 12:08 PM

Quote:

Originally Posted by dennis45

When you add distilled water to the cells, you are diluting the electrolyte. (Lowering the specific gravity) By charging, you are driving the sulphur from the lead plates back into the electrolyte until the battery reaches full charge specific gravity. This takes time.

Now, if you see a charge rate of 14+ VDC for say 8 hours, it is likely an indication the batteries will no longer accept a charge and are in fact toast.

Most OEM batteries are not of the highest quality will not last as long as some others such as Trojan etc but they should, with decent care, last for at least 5-6 years or longer.

Thanks Dennis, makes sense...

OLYLEN · 01-25-2015, 06:34 PM

You said with fridge running. On gas or inverter? If on gas the batteries should have held over night, if on the inverter and a warm refer you could have used up all they have. When ever adding water to the cells it takes maybe four hours to 90% then another two for the last bit of charging. Plug in and let them charge at least overnight and then evaluate if old or not.

LEN

spanuts · 01-26-2015, 08:30 PM

thanks Dennis that's the best explanation i read on battery maintaince

dennis45 · 01-26-2015, 08:47 PM

Quote:

Originally Posted by spanuts

thanks Dennis that's the best explanation i read on battery maintaince

Hope everything works out for you. Let us know how you make out.

Sent from my iPad using iRV2 - RV Forum

Solask · 01-26-2015, 09:03 PM

Traveled from Indy to Nashville today in freezing temps. Don't think engine alt charged coach batteries much during the 5 hr drive. Hooked to shore power for the night and we'll monitor the situation. The batteries were charging at about 14.3 volts, down to 13.3 volts now.. Seems like batteries are taking a charge?

dennis45 · 01-26-2015, 09:34 PM

Quote:

Originally Posted by Rkh

Traveled from Indy to Nashville today in freezing temps. Don't think engine alt charged coach batteries much during the 5 hr drive. Hooked to shore power for the night and we'll monitor the situation. The batteries were charging at about 14.3 volts, down to 13.3 volts now.. Seems like batteries are taking a charge?

I think what you are seeing is normal. I'm not an Alegro expert but I assume your system works like most others in that it will select the battery set (house or coach) with the lower voltage and apply the charge voltage to that system. Once the house batteries reach full charge, it will switch the charge voltage to the chassis batteries and so on. Hope this makes sense and your lights are still on in the morning.