[Elecraft] [OT] Lead-acid battery question

Mon Apr 8 14:41:36 EDT 2013

The charging voltage was measured with the battery connected.

Although it says "ca 665" on it, judging by the size it must 65 AH!

I charged it for a period of 12 hours with an initial charging current of about 7A, which 
dropped to 2A.

I replaced the old battery because it went dead, and then when I charged it it did not 
recover. I think the voltage regulator was bad and not producing enough charging voltage. 
Then the battery was damaged because I didn't notice it was dead for a couple of weeks.

The new battery also went dead. I then checked the charging voltage and it was 13.8V. I 
thought it was marginal, so I replaced the voltage regulator. Now I'm getting 14.5V when 
the engine is running. But I am thinking that I damaged the new battery when I allowed it 
to die before replacing the voltage regulator.

The connections have been cleaned. It is not particularly hard to start (cranks for about 
5-7 seconds and starts). No drain at all when it is off.

On 4/8/2013 11:22 AM, Fred Townsend wrote:
>
> Vic let me clarify a few issues.
>
> 1.At 665 AH your sealed battery is almost certainly a wet battery (i.e. not a gel).
>
> 2.A charging voltage between 13.5 and 14.2 is normal. 14.5 is a bit high unless the 
> charger is temperature compensated and the weather is very cold (in the area of your 
> generator). Another cause would be if you measured the charging voltage without a 
> battery attached (i.e. no load). _In any event your real problem does not appear to be 
> too high a charging voltage._
>
> 3.A measured voltage of 11.5 is a fully discharged battery. A 1 A trickle charger would 
> need 665 hours (actually even more because of inefficiencies) to fully recharge that 
> battery.
>
> 4.Why did you replace the old battery after 10 years? In your almost ideal circumstances 
> it could easily last 25 years. The nature of lead acid batteries is they fail when 
> _fully discharged_. That can kill even a new battery which may be the case now.
>
> 5.Logically I must ask: Have you fixed the original problem? Battery failure is likely a 
> secondary problem. Ruling out two bad batteries (the old and new batteries) has the 
> generator become hard starting or else is there another drain on the battery?
>
> To find your problem you need to get a fully charged battery and monitor the operation 
> of the generator. Have you cleaned all the terminals and otherwise verified the cables? 
> Does it start hard? Does the started solenoid get warm when not in use?  Is there 13.5 
> to 14.2 volts on the battery posts (don't measure the cable terminals) when the 
> generator is running? When the generator is off is there a battery drain? It may take a 
> milliamp meter to tell but be careful not to use it while charging or you may smoke the 
> meter.  Remember ammeters are always placed in series, never in parallel (instant smoke).
>
> Try these procedures and get back to us.
>
> 73
>
> Fred, AE6QL
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net [mailto:elecraft-bounces at mailman.qth.net] On 
> Behalf Of Vic K2VCO
> Sent: Monday, April 08, 2013 10:13 AM
> To: Elecraft Reflector
> Subject: Re: [Elecraft] [OT] Lead-acid battery question
>
> I see that my original post was not clear. I should have said that after the first 
> instance of a dead battery, after the battery was tested and pronounced good, I replaced 
> the VOLTAGE REGULATOR.
>
> I'm not sure about the type of electrolyte, whether it's gel or liquid, but I think it 
> is liquid. The battery is sealed, though. The capacity is 665 AH with "540 CCA."
>
> I've received several responses to check if the battery is draining when the generator 
> is not running. I should have mentioned that I did this the first time it died, and 
> there was no current drain when it wasn't running.
>
> On 4/8/2013 9:15 AM, Vic K2VCO wrote:
>
> > I know there are those on this list who can help me.
>
> >
>
> > I have a 5 kW generator at my house. It runs automatically once a week
>
> > for a half hour to charge the (sealed) battery. The first battery
>
> > lasted for about 10 years! The present battery is about 2 years old.
>
> >
>
> > Some months ago, I noticed that it wasn't running. I found the battery
>
> > dead. I took the battery back to Batteries Plus where I got it; they
>
> > charged it overnight and tested it under load. They said the battery
>
> > was OK. When I started the generator and checked the charging voltage, it was 13.8V 
> which I thought was marginal, so I replaced it.
>
> >
>
> > Yesterday the generator would not start. The battery voltage with no
>
> > load was 11.5V. I left it on the charger all day. Then this morning I
>
> > checked the voltage and it was 13.5V. The generator started up and the charging 
> voltage was 14.5V.
>
> >
>
> > Do I have a bad battery?
>
> >
>
> >
>
> > --
>
> > Vic, K2VCO
>
> > Fresno CA
>
> > http://www.qsl.net/k2vco/
>
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-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/