Batteries don't charge

[ArmySFCRet]

Let the two house batteries get down to 3.92 volts. Yes, I got stupid, but on with the story. Serviced them but now they won't charge from converter. Voltage from converter is 13.45. Across battery solenoid 9.28. From cutoff switch to solenoid 2.35. I have checked both 175 amp fuses. I also checked fuses on solenoid. It appears the solenoid is not passing power to the batteries and does not click when cutoff switch is pressed.

Would charging the batteries off coach solve this or do I have other issues?

Batteries are dated 1/09 and 2/09 and this is the first time they have been below 10.5 volts.

[RJsfishin]

Maybe if you'd quit *****foot'n around w/ trickle chargers, and get about 50 amps going into them, there mite be some hope. I mean, if the converter was to take over the job, would it be diddling around w/ a lousy 2 amps ??

And finally one post had it right, how can a sillynoid operate if it doesn't have any juice to operate it ??

But, in the end, if you have a cell that's smoking, its history. Then again, never trust the smoke. Break out the nasty ole hydrometer, it will tell you everything ! 🙂

[tatest]

ArmySFCRet wrote:

BFL13 wrote:
I thought the OP said the batteries were at 9.28 and the other side of the solenoid from the batteries was 2.35 then going to the cut off switch converter side it was 13.45, indicating that the problem is the cut off switch not letting the 13.45 through to the solenoid thence to the batteries.

What are the batteries at when disconnected (wires off) 9.28? if 12.x then there might be a mystery load dragging them down to 9.28 from their actual 12.x

Batteries unloaded and disconnected = 3.92
Solenoid output posts = 9.28 (large)
Solenoid input posts = 2.35 (small)
Converter output = 13.45

I think your house batteries may be the source for energizing that relay. If it is electromechanical, solenoid closing a high current switch, you need power to pull it closed, and you don't have it.

I've been there on a set of dying batteries, had to disconnect them and charge them separately before they would connect to the converter. Actually, I couldn't even put a battery charger on them, because my charger doesn't work with a battery that dead, needed about 10 hours on a 500 milliamp source to bring them up to chargable. But they were so far gone that I had to replace them anyway.

[ArmySFCRet]

Replaced both with new series 27s. All is well. Thanks for support and feedback.

[pianotuna]

Hi Army,

You can try a recondition but the one that is 12.35 is severely compromised. Sorta like doing "the twist" with a 140 year old lady.

ArmySFCRet wrote:
Looks like one fried as it went to zero volts. The other one seems to be holding at 12.35 volts.

[ArmySFCRet]

Looks like one fried as it went to zero volts. The other one seems to be holding at 12.35 volts.

[BFL13]

ArmySFCRet wrote:
One battery seems to be coming around.

The other one has one cell "smoking" pretty good at 20 amps. This one did have some exposed plates prior to refilling.

Meanwhile, you must be wondering if your rig will run right even if it did have good batteries. Just stick any old 12v batt in the house spot (borrowed from your car?) to do a system check. Then you will know.

[Clay_L]

mena661 wrote:
These people (RV manufacturers) do such wacky things. You have a solenoid between your batteries and the converter?

Most motor homes do - so the battery disconnect switch which operates the solenoid can disconnect the batteries.

[SuperDutyFiver]

ArmySFCRet wrote:
One battery seems to be coming around.

The other one has one cell "smoking" pretty good at 20 amps. This one did have some exposed plates prior to refilling.

When I rejuvenated a few old batteries that came from my dad's rig and sat quite a while one came up after charging with a trickle for a few days-the second I charged at a high rate and then rested and then low and then rested and then I think I let it sit for a day or 2 and then trickled it until it finally came back up-all said and done one of the batteries recovered pretty good-the other would hold 12.5 or so but not much more. As mentioned above both leaked some because I put too much water in to start.

I'd let your 'smoking' battery sit for a bit with no charger-and also suggest getting hold of a trickle charger and using that next.

[ArmySFCRet]

One battery seems to be coming around.

The other one has one cell "smoking" pretty good at 20 amps. This one did have some exposed plates prior to refilling.

[pianotuna]

hi,

If the plates were exposed to air they should have only been covered with water. If they have been completely topped up watch out for over flow as the jar charge.

Plate exposure is another nail in the coffin.

[mena661]

ArmySFCRet wrote:
Not to sure about them coming back. On charge for almost two hours and voltage has dropped to 2.45. Giving them another two hours and then letting them rest until morning.

Leave the charger on them. Like others said, this is going to take DAYS not hours.

[ArmySFCRet]

Yes, these are two 12 volt 27s. They were topped off with distilled water before I started. Down due to poor PM.

[SuperDutyFiver]

ArmySFCRet wrote:
Disconnected bats and now on external charger. Will wait and see. Using large roll away with gauges. Currently charging at about 18 amps.

On edit: after 45 min, now up to 20 amp charging rate. This is in low setting. Medium setting takes it to 39 amps.

These threads can get out of hand-and people don't read every post-what you suggest above sounds like a good plan-I've had similar experiences and you need to tackle both issues-why the batteries are dead, and charging them back up! My experience has been to top off the batteries with distilled water and then charge at the lowest rate possible-ideally for a few days-let them sit and rest and then charge again and then hit them with a good high rate charge after they've settled for a few days and are maintaining there charge. I takes the plates some time to 'remember' their job, hopefully there not toast and if they were just drawn down and not that old you'll be ok.

Just to confirm-and I'm being super simple minded-you have 12V batts and not 6s right?

[BFL13]

pianotuna wrote:
Hi Mr Wizard,

168 hours = one week.

MrWizard wrote:
hours ?

these things will need DAYS !!!! to any kind of charge recovery

PT from the timing of the posts it looks like Mr Wiz was not responding to yours. Anyway, nobody has solved the OP's problem of why his solenoid is stuck or whatever so it doesn't keep happening even if he got new batts. Spray the solenoid with silicone spray? 🙂