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Topic: Battery advice (Read 1566 times) previous topic - next topic

Re: Battery advice

Reply #20 –
Too many memories of constantly attending to flooded cell batteries and the adjunct cabling when I had my Foretravel store in California in the 80's to ever want to go there again,

Although the newer chargers would certainly help flooded cells care and feeding.

Best results would be to completely remove and service the cabling every six months or so to ensure reliability IMO.

Re: Battery advice

Reply #21 –
Struggled to start this afternoon sunny 50. Drove 10m to auto zone and shut off engine to check batteries.  All starting batteries tested good with 98-99% charge, removed +&- to test batteries.  Technician said didn't look like they needed any cleaning and were in good shape.  3 Duralast 34DL with 660 CCA INSTALLED 8/31/18. Tested alternator while hooked to battery by starting engine.  Started easily without hesitation and no struggle to turn over. Usually struggles to turn over and then finally starts. (Maybe I did have a bad connection) However it showed the alternator was putting out 12.5v when starting and he said should be putting out 14.8v when starting and the  voltage regulator read as bad.  Does that mean alternator should be tested further and maybe replaced? 

Re: Battery advice

Reply #22 –
Tommy,

I hate to say this but most car improvement stores don't have the equipment or knowledge to properly test a DUVAC alternator. You need to find an old time alternator shop that knows what to do.  The standard alternator that is on the shelf will cause you more trouble because it isn't made for a Foretravel RV application.

Mike

Re: Battery advice

Reply #23 –
Tommy,

Exactly where did he get the 12.5 VDC reading?  What was engine RPM?

What did the dash voltmeter show at the same time/conditions?
What did the monitor voltage show at the same time/conditions?

Re: Battery advice

Reply #24 –
The tech did initially say that he didn't have the proper equipment to test my alternator but he wanted to do the test anyway. The 12.5v reading came from the same testing equipment he used to test the batteries that were still clamped to positive and negative post on batteries.  Even though I started engine I did not think to check dash or monitor voltmeters. Engine was at normal idle around 900rpms.

Re: Battery advice

Reply #25 –
Check again at both dash voltmeter and monitor with engine at 1100 RPM.  Let us know what you find.

And, even if voltage was 12.5, there are other things than the alternator that can cause this.  Let us know what you find and we can walk you through troubleshooting (assuming you have a digital voltmeter).  NOT difficult.

Re: Battery advice

Reply #26 –
Dash gauge looked like 12.8 on the needle and the audit monitor was 14.3v at 1100rpm.  Turned over and started quick.  Are they measuring 2 different things?

Re: Battery advice

Reply #27 –
Dash voltmeter is notoriously inaccurate.  But, easy to check:

Locate the battery isolator-- on most, raise the bed and it will be on the front wall of the engine room.

With engine on and around 1100 RPM, check voltage between good ground and:

Center terminal (from Alternator B+/alternator  output)
The two outer terminals-- one to each battery bank.

Let us know what you find.

Re: Battery advice

Reply #28 –
Facing rear bed open. Center 14.8 left13.93 right 14.03

Re: Battery advice

Reply #29 –
Those readings are fine.

Now, check voltage at the two battery banks.

Find out how you went from 13.93 or 14.03 at the isolator (connected by large-gauge cables to the batteries) down to 12.5 that he read at the battery!

Could be nothing more than a corroded or loose connection.