2017 Mountain Aire ... batteries?

[GlampDaddy]

I'm guessing the time has come to replace the original batteries in our coach, but thought I'd run this by the group before parting with the big bucks. It's a 2017 Mountain Aire with eight AGM house batteries and two AGM chassis batteries. We boondocked the last two nights (Friday and Saturday). Friday night after six hours, with all the big power suckers turned off, the house battery level was at 12.1 and chassis was at 12.6. Generator to the rescue and back to the 14s for both. Saturday night didn't fare so well...after six hours the house was at 11.1 and the chassis at 12.6. The gen took three tries to start, but it did, and we ran it all day while traveling.
When we landed at tonight's campground, the displays were confusing at best. We plugged in to good 50-amp power and the SilverLeaf showed ... aw heck, the pictures explain better than my verbosity. Tell me what you think, please. Batteries or something else?

 

[Jim]

What does it show with the 50amp disconnected Buddy? And how fast do the DC amps drop?

 

[AbdRahim]

I only have 6 agms, two yrs old. The best ever after 8 hrs is 12.1. Several times 11.1. Must run generator to stay unplugged all night

 

[GlampDaddy]

What does it show with the 50amp disconnected Buddy? And how fast do the DC amps drop?

Jim, chassis drops to 12.9 in a few minutes. House takes a little longer, but not much…maybe 15 minutes.

 

[TheLooks]

11.1 is doing damage. Every time it goes that low it harms the ability to charge fully. Lithium is the answer but $$$$!

 

[TheLooks]

12.9 is good, but how long does it stay there and is it a surface charge that drops quickly under load.

 

[Kevin D Pem]

How many amp hours of batteries?

 

[GlampDaddy]

How many amp hours of batteries?

210 x 8

 

[Kevin D Pem]

210 x 8

6v or 12v batteries

 

[GlampDaddy]

6v or 12v batteries

These are the house batteries - 6 volt

 

[GlampDaddy]

What does it show with the 50amp disconnected Buddy? And how fast do the DC amps drop?

Jim, just got back to the coach and turned 50 amp off to check the drop. Both sets started at 14.4. Chassis dropped to 12.9 within a minute and dropped to 12.5 in 15 minutes. House dropped to 12.9 in about three minutes and dropped to 12.3 in 15 minutes.

 

[Kevin D Pem]

These are the house batteries - 6 volt

So 840ah right?
So 12.3 after 15 minutes! I assume they have no load? If they have a load, drop the load out and tell us what the voltage reads.

How long have they been charging? 840ah is a lot of power! Consider with 100 amp charging that would require 8.5 hours of charge. And we know that above 80% charge that is not an option.

 

[GlampDaddy]

So 840ah right?
So 12.3 after 15 minutes! I assume they have no load? If they have a load, drop the load out and tell us what the voltage reads.

How long have they been charging? 840ah is a lot of power! Consider with 100 amp charging that would require 8.5 hours of charge. And we know that above 80% charge that is not an option.

Kevin, here's my best answer to your question(s): Last night I removed all the load I could at about 10:30. The Silverleaf display showed the status at 14.4. I slept and six hours later it was 11.1. At that point I started the generator and ran it until 4pm (11.5 hours). During the first hour, I checked the display and it showed 14.4. While checking in to the new campground, getting parked and set up, about 30 minutes, the display dropped to 12.1, when I turned on the 50-amp shore power. 15 minutes later it was at 14.4 again. I'm thinking I've convinced myself that these batteries are on their deathbed.

 

[Kevin D Pem]

After that input I agree. I hate to see someone buy something they don't need. That is why I ask so many stupid questions.
For replacements I would suggest Northstar Blue + lead Carbon batteries. That is of course unless you have fallen for the lithium craze. Then do your research on the plus and minus aspects before you shell out the cash. Plenty of well meaning people that are happy to help with that here.

 

[Rich W.]

14.4 is just your bulk charging voltage - it doesn’t indicate battery health status. The batteries will never hold that on their own. 12.9 would even be high for healthy or even new batteries fully charged and allowed to rest. This document is very informative and always good to review: How To Maintain Batteries - Deep Cycle Battery Store .

All that said, if your house batteries are dropping to 12.1 fairly quickly with no load then they have definitely aged. You might get some more use out of them, but the time is comming to replace them. But six years isn’t bad. If cared for perfectly 100% of the time you might get seven or eight years out of them but we all push our house batteries a little too far from time to time. Your chassis batteries appear to be healthy (12.6 after sitting 6 hours is normal), but chassis batteries don’t get the hard use (repeated deep cycling) that house batteries do.