I have a 2006 Tiffin Allegro Bay 38TDB Freightliner 26000. I currently have a TrippLite inverter/charger and have been plugged in to shore power constantly for over a year. I had to replace the 3 year old house batteries a couple of months ago due to the 12v system going down several times. Before the haters start hating please know that I never contemplated owning much less living in an RV. I got cancer and lost my home in 23 and was forced into this life. I am mechanically inclined and most of the repairs I have had to do myself as I now live on disability. Mechanic's daughter. I start the coach every once in awhile as I feel that it's necessary to let the fluids flow periodically in any engine. Yesterday, I went to start it since I'm moving to a different location and when I turn the key....nothing. That is the first time it hasn't started.Attempted to disconnect the series (2 6v deep cycles wires in a series) to charge them individually, and the charger won't charge. My voltmeter read 4.7 in each 6v. Help!?!? I don't know what to do now. Please be kind and helpful. I don't need negative comments. Thank you in advance for any help offered.

as said, the 6V should be your house batteries not your starting battery, but I am more interested in how, being plugged in and your batteries are not fully charged, which makes me wonder if there is something wrong with your inverter/charger, or even something as simple as a fuse or breaker tripped.

Agreed. If you are on shore power and have dead house batteries then they aren't charging. Likewise with the chassis. OP mentioned they periodically start the RV but likely not running long enough to charge the chassis batteries. So each time it's started it draws down more. And if they aren't charging then they're probably dead too. My guess is, this is the root of the issue. OP has to figure why the batteries aren't charging and it sounds like they need new chassis batteries and house batteries - again. But continually buying new batteries without fixing the charging problem is going to be an expensive cycle.

Thanks for coming back to let us know the status. Glad you got it charged enough to crank the engine and it seems like you found the root cause of your issues, which is often more than half the battle with RVs. Could be as simple as just replacing the inverter/charger which is cheaper than your batteries.

No problem. These communities/groups have been very helpful. Thank you again.

Are you testing/charging your house batteries or chassis batteries? Your chassis batteries are what starts/runs the RV's engine. Your house batteries (which appears to be what you are talking about) runs the 12V house side of things (lights, tstat, water pump etc). Your charging system "should " charge both on shore power but your chassis batteries could just be bad. You said you replaced the house batteries, but starting your engine is all about the chassis batteries. What's the state of those?

Chassis batteries not charging | Good Sam Community

14 Replies

Grit_dog
Navigator
May 11, 2025
Still some confusion here. If you’re plugged into shore power, regardless of whether your converter also charges the chassis/start batteries or not, and your 12v systems still work then your converter/charger is working.
It’ll put out enough dc amps to run the house lights etc. (I think it should anyways. If house batteries are very low and then plug into shore power the 12v works again instantly in the campers I’ve had that happen).
pjh64812
Explorer II
May 09, 2025
I was able to bring the chassis batteries back enough to crank. My chassis batteries are two twelve volt wired parallel. They were purchased 8/23. I think my inverter/charger is failing but I'm darned if I can find the problem
Not sure how to isolate so I reckon I'll be calling an electrician. This is beyond my ken. .
- stevenal
  Nomad II
  May 10, 2025
  Not all RVs are set up so the converter keeps the starting battery(s) charged. Are you sure you even have this kind of setup? When left sitting for a while, I use an exterior receptacle on my camper to power a battery maintainer under the truck hood.
  - way2roll
    Navigator III
    May 11, 2025
    OP stated the house batts were bad too.
way2roll
Navigator III
May 08, 2025
To the OP, what does this statement mean; "I had to replace the 3 year old house batteries a couple of months ago due to the 12v system going down several times. " ?
When you say the 12V system went down, were the batteries dead, did a fuse in your inverter/charge trip? Putting the pieces together, it sounds like your inverter/charger may be bad. But again, need more details and clarity. hopefully the OP returns.
- pjh64812
  Explorer II
  May 09, 2025
  I'm inclined to agree. The inverter/charger should keep both chassis and house batteries charges while I'm plugged in to shore power. I had the 12v system go down 3 times and could only identify a problem the first time. I had to replace the cable connecting the series. Went down twice more and I replaced them. Now it's the chassis batteries that aren't 2 years old. . time to call someone me thinks. Thank you all!
StirCrazy
Moderator
May 08, 2025
as said, the 6V should be your house batteries not your starting battery, but I am more interested in how, being plugged in and your batteries are not fully charged, which makes me wonder if there is something wrong with your inverter/charger, or even something as simple as a fuse or breaker tripped.
- pjh64812
  Explorer II
  May 09, 2025
  I've checked all fuses and breakers that I can determine are related. It seems the inverter/charger is not functioning as it should.
- way2roll
  Navigator III
  May 08, 2025
  Agreed. If you are on shore power and have dead house batteries then they aren't charging. Likewise with the chassis. OP mentioned they periodically start the RV but likely not running long enough to charge the chassis batteries. So each time it's started it draws down more. And if they aren't charging then they're probably dead too. My guess is, this is the root of the issue. OP has to figure why the batteries aren't charging and it sounds like they need new chassis batteries and house batteries - again. But continually buying new batteries without fixing the charging problem is going to be an expensive cycle.
Grit_dog
Navigator
May 07, 2025
Sorry to hear of your situation.
So what he said above. Seems like you’re confusing house batteries with start batteries. As the start batteries wouldn’t or shouldn’t be 6v deep cycle. Too high of loads when starting the bus.
Right now not enough info, assuming neither set of batteries is charging and your simply running off shore power. Although the converter has to be putting out decent amps if the house batteries are also dead (4.7 is basically dead) and you can use all the 12v stuff like lights.
- pjh64812
  Explorer II
  May 09, 2025
  You're all correct. Although I know which are which I assumed my chassis batteries were the same as my house batteries but they're two 12v wired parallel instead of the series. I managed to get them charged and the coach cranked but there is a problem with the charging system. I'll have to call someone with more knowledge than me.... shouldn't be difficult lol. Thank you all.
  - way2roll
    Navigator III
    May 09, 2025
    Thanks for coming back to let us know the status. Glad you got it charged enough to crank the engine and it seems like you found the root cause of your issues, which is often more than half the battle with RVs. Could be as simple as just replacing the inverter/charger which is cheaper than your batteries.
way2roll
Navigator III
May 07, 2025
Are you testing/charging your house batteries or chassis batteries? Your chassis batteries are what starts/runs the RV's engine. Your house batteries (which appears to be what you are talking about) runs the 12V house side of things (lights, tstat, water pump etc). Your charging system "should " charge both on shore power but your chassis batteries could just be bad. You said you replaced the house batteries, but starting your engine is all about the chassis batteries. What's the state of those?

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Chassis batteries not charging

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