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Topic: Inverter battery question (Read 482 times) previous topic - next topic

Inverter battery question

I had the inventor activated and it showed a 12v charge. After only running a fan for 5 minutes it showed 11.5v. Do I have a bad house battery? Shouldn't the charge be up to 13v and take hours if not days to discharge?

Thanks
Build 5477
99 3602 WTFE U270C

Re: Inverter battery question

Reply #1 –
Yes, a bad battery is a possibility.  If wet cell, use a BATTERY HYDROMETER (any auto parts house) to check the cells AFTER charging (perhaps with alternate charger).

In bulk mode (when first turned on, unless batteries deeply discharge, voltage should be around 14.  Then taper off to 13.2-13.5 in float mode.
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: Inverter battery question

Reply #2 –
I had the generator running 5 hrs on Sunday and the inventer turned off since. I'll have it plugged in over the weekend. I'll see what it charges to. It should automatically charge shouldn't it? The battery is sealed. If I need a new battery what's recommended?
Build 5477
99 3602 WTFE U270C

Re: Inverter battery question

Reply #3 –
You should have 2 8D Gel batteries, usually MK brand made by East Penn. A lot of folks replace them with AGM versions which are more readily available and somewhat less costly. The cheapest route is to use flooded lead acid deep cycle batteries, but this would require some recabling as they are most readily available in 6VDC and therefore would need to have two in series in parallel with another group of two (4 total) to get the 12 volts. You would have to figure out the right group size to fit the existing tray if you went that route. Easiest thing to do if you are the one doing it, is to locate a good price on some 8D AGM batteries (Absorbed Glass Mat) and then the existing cabling and tray would be a direct replacement, assuming yours is as it came from the factory and hasn't been altered. You are talking about the house batteries, right? The chassis batteries aren't charged by the inverter/charger either on shore power or generator power unless the boost switch is on, but they don't supply any of the house loads. Only the drive train and most of the dash items.
Don
Quote from: goldbehen –
I had the generator running 5 hrs on Sunday and the inventer turned off since. I'll have it plugged in over the weekend. I'll see what it charges to. It should automatically charge shouldn't it? The battery is sealed. If I need a new battery what's recommended?
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Inverter battery question

Reply #4 –
I was looking at lifeline AGMs. They weigh 162 lbs each. I think I only have one battery powering the house. Didn't know I needed a pair. Will the tray support 300lbs?
Build 5477
99 3602 WTFE U270C

Re: Inverter battery question

Reply #5 –
 Should be no problem if it will hold at least 2 8Ds (size wise) My set up hold 3 as many other coach's do too.
I also have the Lifeline brand and they weigh that same as other makes of same type.
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Inverter battery question

Reply #6 –
If it doesn't have a pair now, then one must have failed and they removed it, which means you may not have the cabling to put two 12V AGM 8D's in parallel. Your battery is on a slide out tray, right? The reason for two is to have more available amp hours without going into as deep a discharge. Discharging more than 50% will dramatically shorten the batteries life span. It is best practice to replace all the batteries in a battery bank at the same time and have the batteries be the same age (as new as possible!). O'Reilly's has what I believe is East Pen/Deka/MK AGM's under their house brand label  for $450 apiece. I just bought four of them to double the size of the battery bank. U270's came with two MK Gels, U295's and U320's came with 3. The third was on a shelf or slide out tray above the other two. There is room for 4 in that compartment on Unicoaches of that vintage. There is framing to support a second level of batteries on our U270 because all the Unicoaches shared the same framing with a few exceptions, so there is steel where needed for certain options or upgrades.
Don
Quote from: goldbehen –
I was looking at lifeline AGMs. They weigh 162 lbs each. I think I only have one battery powering the house. Didn't know I needed a pair. Will the tray support 300lbs?
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Inverter battery question

Reply #7 –
I'll take a look at the cables . I assume I can wire a pair in series or parallel . I'll look into the off label AGMs mentioned.
Build 5477
99 3602 WTFE U270C
 

Re: Inverter battery question

Reply #8 –
Quote from: goldbehen –
I'll take a look at the cables . I assume I can wire a pair in series or parallel . I'll look into the off label AGMs mentioned.

Yes, 6 VDC batteries in series

12 VDC batteries in parallel.

If more than 2 six volts, wire the min series to make 12 VDC and then wire those in parallel.
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