[RE-wrenches] intermittent battery problem

[Jonathan Hill]

Ron-
We've seen this issue before,and it is almost always due to badly sulfated batteries. I'd try a LONG (8-12 hrs) EQ charge at 32 volts. We've done this with Hawkers and fixed the problem. I believe the Surrettes could handle this kind of charge, though you might contact Jamie Surrette.

Jonathan Hill, senior system design engineer
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On Oct 8, 2011, at 6:42 PM, Ron Young wrote:

> Thanks Bob but he has a tubular type hydrometer, not the pointer type. They're usually ok but I'll check it against mine when I go there which looks like a certainty.
> 
> They EQ the batteries on a regular basis as per my instructions (they say) but will have to nail them down on that. The small 2500w generator worries me but they have 800w solar and a Whisper 100. The wind blows a lot. Inverter is a 3524 Outback.
> 
> Ron
> 
> On 2011-10-08, at 5:07 PM, bob ellison wrote:
> 
>> I bet he has a cheap pointer type hydrometer, I have seen them be way off from reality.
>> My guess is that the gravity is low the voltage changes quickly, specific gravity changes slowly in a battery bank.
>> To fully charge a 24 volt bank you need to get it to 29 + volts and keep it there for several hours, depending on the battery bank size.
>> Charging it to 25.4 is nothing in the long run.
>> Give them a LONG full charge, what are the inverters? Does it ever get an EQ charge?
>>  
>> Bob Ellison
>>  
>> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Ron Young
>> Sent: Saturday, October 08, 2011 2:02 PM
>> To: RE-wrenches
>> Subject: [RE-wrenches] intermittent battery problem
>>  
>> Howdy Wrenches,
>>  
>> One of my customers that lives 3 hours out in the back country is having an intermittent problem that I haven't encountered before. The batteries drop rapidly in voltage but hydrometer readings are in the green. Turning off the inverter and just using DC doesn't change anything. Meters on the Mate, Outback MX and Whisper controller are all the same so it's not a metering problem. On the way to bed the batteries were at 25.4, overnight with no loads they dropped to 22.9 then a short 15 min. charge with a generator brings the batteries back up and two hours later they are at 25.8. This scenario has occurred several times and then doesn't appear for a day or two.
>>  
>> It doesn't seem to be sulfation as the batteries are reading good on the hydrometer every time. All cells check out. The inverter doesn't seem to be the problem. They have a Sunfrost on a separate DC circuit. It sounds like an intermittent circuit problem or electronics issue. Customer has checked and tightened all the connections he can get at but hasn't been inside the components. Would appreciate any suggestions or clues before I make the trip.
>>  
>> Ron Young
>>  
>> earthRight Products - Solareagle.com
>> Alternative Energy Solutions ~ Renewable Energy Products
>>  
>>  
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