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Author Topic: Bad batteries or bad inverter, how do I tell?  (Read 1474 times)

lb0456

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Bad batteries or bad inverter, how do I tell?
« on: July 10, 2012, 10:23:23 PM »
Batteries are charging from the alternator on the engine but will not charge from shore or generator.  All plugs work when we turn the inverter on.   The microwave only works when inverter is on.   How do we tell if it is bad batteries or a bad inverter?  I think the water was low in the batteries when we checked them.


Thanks in advance for any help.

Linda

Just Lou

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Re: Bad batteries or bad inverter, how do I tell?
« Reply #1 on: July 10, 2012, 11:17:24 PM »
Sorting through the list of stated facts might reveal the following;
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Batteries are charging from the alternator on the engine but will not charge from shore or generator.
Either the voltage from the converter (activated by shore power or generator) is not reaching the batteries or the converter is NOT working at all.
 
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All plugs work when we turn the inverter on.
Means the inverter is okay.
 
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The microwave only works when inverter is on.
Means the inverter is okay.
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How do we tell if it is bad batteries or a bad inverter?
First, you have proven that the inverter is okay.
Second, if you have good bright interior lights when hooked to shore power, or running on generator, then your converter (the device that makes your 12v and should be charging your batteries) is working fine.  If it does not ALSO charge your batteries then you have a problem of a possible battery disconnect switch being turned OFF, tripped DC circuit breaker, blown fuse, bad isolator/charge relay or poor battery connection.

Tell us more about your particular RV (such as make, model and year) and we can be of more help.


“You don't write because you want to say something, you write because you have something to say.” F. Scott Fitzgerald
lou  ---  '97 Bounder 34V (F53 w/tag), '99 Honda Accord EX

John From Detroit

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Re: Bad batteries or bad inverter, how do I tell?
« Reply #2 on: July 11, 2012, 11:17:35 AM »
Based on what you said I would suspect 1: The circuit breaker feeding the converter is tripped.

2: Converter, if a plug in model like mine, not plugged in

3: Blown fuse or tripped push-to-reset breaker

4: Bad converter

However, the only way to tell if it is NOT the batteries is this.. It is also one of the very first steps in this trouble shoot.

Connect batteries to an external smart charger for 24 hours, unhook (Completly, disconnect from RV, remove NEGATIVE lead from battery for one hour, Load test.

If the batteries pass the test.. They are good.
Nothing adds excitement like something that is none of your business
My Home is where I park it.

lb0456

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Re: Bad batteries or bad inverter, how do I tell?
« Reply #3 on: July 20, 2012, 09:28:39 PM »
Thanks for the responses.  Sorry didn't respond sooner.  I thought I would get email when I got responses.
The RV is a  2008 Holiday Rambler Endeavor.  A mechanic looked at it and said he thought the inverter was working but the charger on the inverter was not so my husband put a battery charger on the batteries and it is charging but it doesn't seem to hold the charge for very long.