Batteries keep going dead

[Rgruber]

We have a 2018 355 mbqs. It has two 12 volt deep cycle batteries powering its DC system. Problem is they keep dying even when they are switched off. I replaced them two weeks ago and after one week they were dead. They must be leaking power somehow.

Any thoughts?

[sean.harp]

Disconnect them. There are things that will drain them even when disconnected (CO detector for one). I installed a easy disconnect at the battery negative terminal and disconnect completely when storing. Mine were dead in less than 2 weeks on my 2017 325bhqs.

[Vicr]

Install a battery disconnect switch.

[Johnny Lightning]

You didn't say how long it took the batteries to go dead so it's kind of hard to tell if it's normal or not. Like the previous poster said, get a battery disconnect switch, it will help if the storage is for fairly short term, say less than a couple of weeks, maybe a couple of months or so. Lead acid batteries also do what they call internal discharge where just sitting, with no load connected, they will discharge. This usually takes a couple of weeks to a couple of months or longer depending on the battery, temperature etc. Usually the better the battery the longer it takes. One of the ways that you can prevent this is to get a battery tender, (note this is NOT a trickle charger). This needs to be plugged into an electrical outlet to keep the battery charged. You can also get solar battery tenders these days that will keep batteries charged up from sunlight. Again, make sure it is a"regulated" solar panel not just one that clips on to the battery with no electronics to regulate it. I hope this helps.

[GHen]

We are all in the same boat.
2017 291rsts, batteries always are also dead after a week or so. Factory battery disconnect is useless. It leaves too much on.

I added a 100 watt solar panel, that helped, except in winter. Need to disconnect the batteries or plug it into shore power.

[jimp]

Can buy a small 1.5-3amp battery maintainer/charger and use QD plugs to make connections a 10 second job. I have a smaller TT but a 1.5amp works great on mine. I used 2 on the old Class C I had.

[kirchh13]

We have a 2016 355MBQS and the first year we constantly had dead batteries. The battery disconnect was wired wrong from the factory and didn't actually disconnect anything. After a few trips to the dealership for service, the disconnect was finally wired correctly. No dead batteries between trips after that.