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Topic: House Battery Testing (Read 949 times) previous topic - next topic

House Battery Testing

Hello all, can u test house batteries like u do a wet cell, I need to test mine,( Gel ).
  I am losing too much voltage when boon docking.Should I charge them up and then test or test when at low voltage?? My batteries were born April-2004

Ben
1999 u320

Re: House Battery Testing

Reply #1 –
Batteries must be tested when fully charged. 

Yes, you can LOAD TEST them like wet cells, assuming you have the equipment to do a load test.  If not, most places that sell batteries will test them for free.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: House Battery Testing

Reply #2 –
How are you charging your batteries? Load test at Full Charge.

Regards,
Jon Twork
JON TWORK KB8RSA
Full Time RVer (10+ Years) & Dedicated Boondocker
Retired, Unemployed, Homeless Transients
1996 Foretravel U270-36 w/24' Timberwolf Trailer
I firmly believe that tomorrow holds the possibility for new technologies, astounding discoveries, and a reprieve from my remaining obligations.
Welcome to WeRV2 (Under Construction)
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The Second Amendment is in place in case they ignore the others.

Re: House Battery Testing

Reply #3 –
Brett, What voltage do you consider fully charged 13.2-13.5 ? What voltage do you consider bad?

Jon, I have a 10amp charger that I am going to charge the batteries separately, is this ok?

Thanks.

Ben

Re: House Battery Testing

Reply #4 –
Ben,

Don't you have a Link 2000 in your U320?  You can do a load test yourself if you do.  Fully charged batteries float at 12.8v after the surface charge is gone.  Put a constant load on them(like with all your inside lights) and see how many amp-hours the batteries can supply before they reach 50% capacity at 12.2v.  Then compare what you get with the amp-hour capacity of new batteries.

How much work have you done eliminating parasitic loads when you're boondocking?
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: House Battery Testing

Reply #5 –
Quote from: Ben and Bonnie –
Brett, What voltage do you consider fully charged 13.2-13.5 ? What voltage do you consider bad?


Thanks.

Ben,

Ben

It is a little more complicated than just reading voltage.  While charging, once the amp output of your charger is able to provide enough "power" to get to pre-set bulk rate voltage, your voltage will read 14+ VDC-- even if the batteries are no where near fully charged.

If you have a Link system or other ammeter, amps of charge is a better indicator of charge level. 

With your 10 amp charger, an estimate would be to assume full charge when amp charge rate drops to about 2 amps.

And, as mentioned, once the charger is disconnected, the surface charge will dissipate quickly-- dropping voltage from 13.5+ to about 12.8 very quickly.  12.8 VDC is a proper reading for a fully charged battery (yes, different battery types can vary by .1 VDC or so). Anything above this is surface charge.

And, to load test them "at home", use the inverter and put a heavy load on them (microwave, etc).  The low amp/time test described above is also a good test.

Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: House Battery Testing

Reply #6 –
YEA, :)) :)) I think that it is fixed, removed bottom battery from battery tray, pulled inner back one to front, then I removed cables from top one,cleaned and load tested-it tested good. I have a slide so there is a brace in front of the top one. Cleaned all connections and load tested other two batteries and they were good also. I went to compartment where 12v fuses were located and  removed all connections, cleaned and retorqued. Went inside of coach and prosine read 12.75. Hooked up 50 amp cord to coach and it was charging 13.9 on monitor. I would say bad connection on one of the batteries???
Time will tell if it is fixed for good.
Ben
1999 u320

Re: House Battery Testing

Reply #7 –
Small tidbit, Gel batteries should not exceed 14.2 VDC, on my 01, 320 Xantrex, when charge is needed, the system charges up to 102 amp, and steps down over time, but the key word is it keeps charging for 3 hours, but does not exceed the 14.2 VDC.  This is how  my auto battery charge setup has been established and it seems to work fine.

For me, I would think the 10 amp charger would take a very long time to fully charge the battery setup, assuming you have the 3, 8D Gel setup in your 320.
Good Luck and enjoy