Community Forums

MartinGale · 02-22-2019, 05:59 PM

My 2002 Winnebago Journey has had low voltage on both house 12.9v and chassos 11.2v from when I purchased it back in October 2018. It has actually always started without need to boost to the house batteries.

I decided that before I put money into new batteries, I would add an AMP-L-START. Long story short is, after the install and turning everything back on, the house battery is 12.1v and chassis is 11.0v. When I turn on the charger, it indicates battery is in middle condition. Shows charging at high rate. It quickly, like less than 5 seconds, shows battery fully charged and amperage drops back.

Okay. Now the details. The house batteries are 2 EverStart 29DC batteries with a date code of 06/18 and a smaller EverStart battery of unknown vintage.

Chassis batteries are 2 size 31 Contental that are way beyond normal service life. My principle concern is my house batteries. If the smaller EverStart has a dead cell would it cause the charger to cut back automatically? I have already purchased a third to replace the mismatched small one. I am just trying to figure out the behavior and speculate on the cause. I welcome any ideas.

I admit to being totally in the dark. I wonder why the house batteries chose this time to fail. Or if the charger has suffered due to something we did during the disconnect and reconnect?

cavie · 02-22-2019, 06:12 PM

Pull all three batteries and have then charged and load tested. Not just an electronic load test but a real LOAD test.

MartinGale · 02-22-2019, 07:05 PM

Thanks for the suggestion. I will probably wind up doing exactly that. The 2 large deep cycle batteries should still be under free replacement warranty. The true load test should reveal any potential problems.

While I understand the need to load test to discover the exact problem. I am just curious if the behavior is typical for failed batteries.

On a normal old school battery charger, if a battery had bad or shorted cell, they normally ramp up to maximum power and boil the batteries. Is the charger/inverter used in the Winnebago smarter than most old school chargers?

MartinGale · 02-23-2019, 03:22 PM

I got the house batteries out and put the oldest, smallest on my smart charger. It showed 95% at 12v. Huh? Even though I was sure it was junk, I left it on 15Amp charge for a couple of hours. No change,

I have connected one of thev29DCs up to charge. It shows 50% at 12v. Could see the capacity increasing as I watched. I have bought a 100Amp load tester and ordered a battery refractometer. Should get the refractometer on Monday. I am willing to bet the small battery has opened cell(s). I did check acid level and all cells even and above the plates.

I did manage to pick up a 29DC with meager 1 year replacement warranty. It is same brand and capacity of the, hopefully, good house batteries.

Isaac-1 · 02-23-2019, 07:42 PM

I just want to add that battery banks should be matched sets, same brand, model, and manufacture date. Mismatched sets can kill batteries, as some will over charge and some will under charge

cavie · 02-24-2019, 03:39 AM

Quote:

Originally Posted by MartinGale

I got the house batteries out and put the oldest, smallest on my smart charger. It showed 95% at 12v. Huh? Even though I was sure it was junk, I left it on 15Amp charge for a couple of hours. No change,

I have connected one of thev29DCs up to charge. It shows 50% at 12v. Could see the capacity increasing as I watched. I have bought a 100Amp load tester and ordered a battery refractometer. Should get the refractometer on Monday. I am willing to bet the small battery has opened cell(s). I did check acid level and all cells even and above the plates.

I did manage to pick up a 29DC with meager 1 year replacement warranty. It is same brand and capacity of the, hopefully, good house batteries.

Like Isaac-1 stated. You can't mix old and new batteries. Nor can you mix different size batteries.

twinboat · 02-24-2019, 05:04 AM

There is no reason NOT to mix, in parallel, old and new batteries, if they test good. You can also mix different size batteries in parallel.

Batteries charge by the same voltage, whether new or old.
Batteries do loose capacity with age, so you may have less capacity then when all are new. 1 new and 1 old 100AH battery may add up to 150 AH.

If the battery tests BAD, then don't use it.

Here are 2 links, of many, explaining how batteries charge and discharge. There are many others.

http://rvnerds.com/2017/08/07/electr...gescapacities/

https://www.yandina.com/combInfo.htm#Q2

lwasouth · 02-24-2019, 09:30 AM

Sounds like a bunch of batteries that their condition is really unknown. How many shorted, or have gone dry to expose plates, They are all a cheap brand of batteries The money that has been spent on tests, equipment and such, would have been better spent on new deep cycle batteries (Good batteries made by a company called "East Penn") sold under several brand names,but about 30% more expensive than the "Cheap" batteries

MartinGale · 02-25-2019, 07:37 PM

The newest (read just purchased) 29 Deep Cycle battery was installed with no other house batteries. It fell from 12.8v to 11.8v in 24 hours with no load.

I am pulling the Charger/Inverter tomorrow. I understand the inherent problems with mixed batteries. I just do not feel like spending a bunch of money on new batteries to deplete them with a malfunctioning charger. Discharging to 50% capacity is hard on any battery.

I appreciate everyone’s suggestions.

MartinGale · 03-01-2019, 11:58 AM

After a lot of grunt work we got the charger inverter out. Upon visual examination, the circuit boards all look good. Capacitors have no visual signs of damage. No obvious overheated components. I am discouraged by the lack of a schematic. I have ordered a replacement due to the difficulty trying to diagnose without documentation. I will probably put it on the bench later and poke around to see what I find.

I purchased a Xantrex Freedom 458 20-12 Inverter/Charger - Single Input/Single Output which should be compatable with the currenr remote panel. The original Freedom 15 had DC connections made internally. This new unit has connections on the rear which should make installation a breeze. New unit includes battery temperature sensor as a bonus. It does get hot in Texas so it might keep me from cooking my batteries.

I hope to get it installed sometime the middle of next week, assuming UPS doesn’t misplace it.

I guess while I have the batteries out, I can fix the bad light switches on some of the house lights. It seems the list of upgrades and repairs is never ending. I cannot wait to see how long we can dry camp with good batteries.

MartinGale · 03-10-2019, 02:54 PM

I installed a new Freedom 458 Single Output inverter. The original Freedom Basic Remote worked perfectly. Ater installing, I could see all three stages of battery charging. Currently the batteries are at 13.4 volts while maintenance charging. After disconnecting from shore power batteries are holding charge.

So, in the end I replaced a single deep cycle house battery. The charger on my old charger/inverter was bad and I opted to buy a new one rather than trying to repair the old charger. The lack of documentation was disappointing.

Anyway, my out of pocket expense was less than $1000 including cost of new deep cycle battery, Freedom 458, battery disconnect and needed cable to install. This was way cheaper than buying unneeded high priced batteries that would have accomplished absolutely nothing.

I appreciate people’s advice, but it is necessary to follow a logiccal course of action, which for me solved the problem.

MartinGale · 03-10-2019, 04:21 PM

Quote:

Originally Posted by twinboat

There is no reason NOT to mix, in parallel, old and new batteries, if they test good. You can also mix different size batteries in parallel.

....

Here are 2 links, of many, explaining how batteries charge and discharge. There are many others.

http://rvnerds.com/2017/08/07/electr...gescapacities/

https://www.yandina.com/combInfo.htm#Q2

My experience has been that with similar batteries charging to the same voltage there is absolutely no reason to worry. I am a believer in proper charging, avoiding extreme discharge and only storing when fully charged. I have had very good results on my cars, trucks and motor home. Although my last motor home was long ago. Thanks for the links.