Is it bad to leave the coach plugged into shore power full time

[relaxn]

We just had a guy come out to look at some slide issues on our coach and he told us leaving the coach plugged into 50 amp shore power cooks the batteries. I have not heard this before. We have a 2009 Monaco Camelot. The manual claims that when needed shore power will charge the batteries otherwise it will maintain them. I assumed it would not be an issue. Thoughts on this??

I ask because this same "tech" argued with me saying the owners manual was wrong, I should level the coach first and THEN slide the walls out. This is the exact opposite of what Monaco;s owners manual says. So yeah....I'm not convinced I should be listening to him.

[Damon Diva]

We have kept all of our motorhomes plugged in 24/7 at our home for decades. The first two were 30 amp Bounders. We changed the service box to 50 amp when we got our Diplomat. We then updated our current "Diamond" to 50 amp.

I think we replaced one set of batteries in this 30 year period of time.

[keger]

Start looking for a new service tech. He should have stated why his opinion differ from the MH manual not argued. Our five month stay in Florida I had the MH plugged into a 50 amp service and no issues with the batteries.

[swampdog2]

I also left mine plugged in for 2 months ! it boiled all the acid out of my 4 six volt batteries and killed them dead .Maybe it wasn't suppose to but it did.

[Dtwallace]

Originally Posted by swampdog

I also left mine plugged in for 2 months ! it boiled all the acid out of my 4 six volt batteries and killed them dead .Maybe it wasn't suppose to but it did.

swampdog,
Before you lost your batteries. When was the last time you had serviced them?

I ask because the same thing happened to me.

But I know it was my fault for not inspecting and servicing my batteries on time.

I keep our coach on shore power 24/7 still and have had no issues with the new batteries.

Dtw

[Sandy Swede]

Originally Posted by swampdog

I also left mine plugged in for 2 months ! it boiled all the acid out of my 4 six volt batteries and killed them dead .Maybe it wasn't suppose to but it did.

If you leave your coach plugged in all of the time and you don't maintain water level in the batteries, then yes, you run the risk of ruining the batteries. The float charge mode should should never be the cause of ruining a well maintained battery. That being said, if the float charging function on the inverter/charger is damaged and it continually applies full charging, that is another story.

I suggest the OP find another tech.

[GBDTN]

We live in our coach, so its plugged in or on the road. 4 to 5 months is max for filling with water. The fumes from the boiling was ruining everything so as many recommended, i added mineral oil and it has helped, but now i have to add water about every 3 months, so i had the bright idea to turn off the coach battery’s, everything worked great. About 6 hours later DW said “oh no the fridge has quit” frig wont work with batteries disconnected. Batteries still boiling on my coach and adding water. I have thought about adding a manual disconnect at the batteries but then the charger?? Always something to work on or ponder.

[l1v3fr33ord1]

relaxn-

Time for a different tech.

On the leveling-slide issue, follow what the manual says. Every coach is different, but it's common for Monaco manuals to specify slides out first, followed by leveling.

On the battery issue, I offer this observation: At any moment there are hundreds of thousands of RVs connected to shore power for extended periods. If battery destruction was the "usual" result, you'd see reports of same all over- and you don't. Ergo, it's not a problem.

That said, if a charger does not apply the correct float charge voltage, battery destruction or depletion can occur. Frequent loss of water in the cells, "boiling" and the like are symptoms of:

a) a broken charger, or
b) a charger that does not have a float charge setting (common for older, "single-stage" chargers)

[timjet]

+1 on find another tech.

My manual says to level the coach first before extending the slides but I'd do what the manual says concerning the slides.

With a 3 or 4 stage battery charger, it will not damage the batteries leaving the coach plugged in all the time BUT you still must monitor the fluid level once a month or so. Some folks add an ounce or two of pharmacy grade mineral oil to each cell to slow evaporation. Works for me.

[Waiter21]

We just had a guy come out to look at some slide issues on our coach and he told us leaving the coach plugged into 50 amp shore power cooks the batteries.

Yes, Maybe.... Depends on your converter.

On my ole Mirada, it had a single stage converter, it was adjusted to provide one voltage regardless if the batteries were dead or fully charged, so if the batteries were fully charged, and it kept sending out full voltage, it would cook the batteries.

If you have a multi stage converter, it will adjust the charge voltage automatically so it won't cook the batteries.

HOWEVER - Even with a multi stage converter, If you have wet batteries (the kind you add distilled water) its a good idea to check the fluid in the batteries a couple times a year, especially if you leave it plugged in year round.

[Cat320]

All you need is a ''smart'' inverter/converter charger...and keep the batteries topped off.

[Hit_the_Rhod]

Originally Posted by Sandy Swede

If you leave your coach plugged in all of the time and you don't maintain water level in the batteries, then yes, you run the risk of ruining the batteries. The float charge mode should should never be the cause of ruining a well maintained battery. That being said, if the float charging function on the inverter/charger is damaged and it continually applies full charging, that is another story.

I suggest the OP find another tech.

Agree on BOTH items!

Older, or newer defective chargers will ruin the batteries. Newer properly functioning chargers shouldn't be a problem. We have never had a problem being plugged in for extended times (like 5 months in storage) BUT we also regularly inspect/service the batteries. Going on 8 years on these batteries, and probably time for new ones in a year or two.

[marjoa]

Originally Posted by relaxn

The manual claims that when needed shore power will charge the batteries otherwise it will maintain them.

Well yes but if...

On the batteries...
Like many have said, IF you have a multi-stage converter should not be a problem. If you have a factory OEM, single stage converter—maintaining means—it will con't to send a charge to the batt's regardless of whether they need it or not and over time ruin the batt's and will cook out the water. Wet batteries always need periodical checking of the water levels. OEM single stage converter will not have a Float stage or what some call a Storage mode. A single stage converter also makes boon docking almost impossible too because, it doesn't have the ability to do a quick "boost" charge when needed, therefore you have to run your generator A LOT to recharge the batt's back to a full state. There's a lot more to this but I'll keep it simple for the sake of this thread.

Our coach is 50amp too, and about 3 weeks ago, I just changed out our OEM single stage converter for a Progressive Dynamics PD9260 Multi-Stage Converter (4 stage) along with changing out my 2 - 12V Interstate batteries for 2 - 6V Trojan T-105's. Trojan and many here say to check the water level about once a month. Especially in the summer. So, I also added a watering system to make this task easiier to maintain. Then I installed a TRI-METRIC 2030 Battery Monitor so I know the—exact state—of the batteries at any given time whether charging or discharging. Not a normal OEM monitor that usually says something like, "good, fair, bad". I love our new system. It's miles above OEM.

Check and be sure what type of converter you have. If it's single stage, I highly recommend changing it out to a multi-stage.

https://www.progressivedyn.com/rv/po...vertercharger/

On the slides...
I don't know about your coach, but on ours, you're supposed to level first, they deploy the slides.

[TMan59]

Monaco is very clear to extend sides hike aired up, before leveling.

Any good tech should know this in my opinion.