# Battery Disconnect ?



## Jim B (Mar 26, 2010)

We now have a 30amp hook up for the TT at the house. I know that the power center has a trickle charge mode so is it OK to leave the battery connected all the time ? Or should I disconnect the battery and only reconnect once in a while to recharge ? I know I need to check the battery fluid levels every so often either way.

I had originally put the disconnect on before we added the shore power connection at the house in order to keep the battery from draining. I also added a small 5W solar charger which did a great job of maintaining the battery while disconnected.

We put the power in about a month ago, and it's been great to be able to go out to the TT and have power. The fluid levels are OK.

Just wondering what you all do.... Thanks


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## Oregon_Camper (Sep 13, 2004)

If you already have the disconnect installed, you might as well use it and only charge the batteries before a trip.


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## CamperAndy (Aug 26, 2004)

Toss a coin and turn it off based on the toss. The primary purpose of the disconnect is to prevent the batteries from draining so not needed when you are on shore power but it would not be a bad idea to isolate once the battery is charged, just in case you lose shore power it will not kill the battery.

BTW I leave mine connected all the time so if I do lose shore power the fridge stay running, it stays full all summer long. I check my trailer every day since it is in my yard.


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## Joe/GA (Aug 14, 2009)

I have a shore power hook up at home also and leave my battery connected all the time. I've done this for a year now and my battery has not needed any water added. This is a heck of a testament to how well the converter does at charging the battery. It's a "smart" charger and works great!


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## duggy (Mar 17, 2010)

I always leave my trailer plugged in with the battery connected. Last year, at the end of the season, the battery fluid levels were right where they should be. As already mentioned, they have a smart charger, and it works well.

I had a large boat for 16 years, and the batteries always needed a fluid top up at the end of the season. Obviously the trailers have better chargers than boats did in 1988.

Doug


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## Jim B (Mar 26, 2010)

Thanks. It's good to hear that the new power centers do handle the "smart charge" well. I guess I'll leave it connected during the season and then just pull the battery for the winter.


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## ELSEWHERE (Sep 16, 2007)

From what I've read/been told I think it's best to keep the charger on your batteries all the time. Every time you discharge and recharge a deep cycle you shorten it's life. So if you have power available keep the charger on them. If you take them out of the trailer (winter, etc.) put a trickle charger on them. We've had our trailer three years. We rarely use it during the summer and it sits alongside the house on shore power. We travel 5 to 6 months solid during the winter using shore power and occasionally dry camping with a generator. I don't think I've had to add water more than 2 or 3 times. The original Interstate batteries seem to be holding up well. Again, I'm no expert but this is what I've been told and it works for me. There is someone on this forum who's a battery "expert"...he works in the industry...maybe he'll add to this thread.


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## john7349 (Jan 13, 2008)

CamperAndy said:


> Toss a coin and turn it off based on the toss. The primary purpose of the disconnect is to prevent the batteries from draining so not needed when you are on shore power but it would not be a bad idea to isolate once the battery is charged, just in case you lose shore power it will not kill the battery.
> 
> BTW I leave mine connected all the time so if I do lose shore power the fridge stay running, it stays full all summer long. *I check my trailer every day since it is in my yard.
> *


Yeah, me too. I keep a little AC "night light" in the TT window. This allows me to see at a glance if the shore power is working.


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## Calvin&Hobbes (May 24, 2006)

Well, I guess theres an exception to every rule- I used to leave mine hooked up all the time, but found (twice now) that my fluids were low (plates exposed), and the water is bubbling- all the time. It appears my charger is boiling my batteries. Maybe I have a dysfuctional three stage charger?


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## duggy (Mar 17, 2010)

Calvin&Hobbes said:


> Well, I guess theres an exception to every rule- I used to leave mine hooked up all the time, but found (twice now) that my fluids were low (plates exposed), and the water is bubbling- all the time. It appears my charger is boiling my batteries. Maybe I have a dysfuctional three stage charger?


If the water is actually bubbling, I would say you definitely have a charger problem that needs to be sorted out.

Doug


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## mx33suprdav (Jul 2, 2006)

Calvin&Hobbes said:


> Well, I guess theres an exception to every rule- I used to leave mine hooked up all the time, but found (twice now) that my fluids were low (plates exposed), and the water is bubbling- all the time. It appears my charger is boiling my batteries. Maybe I have a dysfuctional three stage charger?


Mine does the same. Dealer said the charger was working correctly; How can i check it myself?


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## Joe/GA (Aug 14, 2009)

mx33suprdav said:


> Well, I guess theres an exception to every rule- I used to leave mine hooked up all the time, but found (twice now) that my fluids were low (plates exposed), and the water is bubbling- all the time. It appears my charger is boiling my batteries. Maybe I have a dysfuctional three stage charger?


Mine does the same. Dealer said the charger was working correctly; How can i check it myself?
[/quote]

I would fond out which brand and model you have and cjeck it out online. If you have to pull the cover and you're not comfortable working with live power, I suggest you pull the shore power plug and disconnect the battery


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## Gilligan (Aug 25, 2006)

Calvin&Hobbes said:


> Well, I guess theres an exception to every rule- I used to leave mine hooked up all the time, but found (twice now) that my fluids were low (plates exposed), and the water is bubbling- all the time. It appears my charger is boiling my batteries. Maybe I have a dysfuctional three stage charger?


You either have a malfunctioning converter or one or more of the battery cells is shorted.
When a cell shorts out, the battery effectively becomes a 10V battery. Even the modest 13.2V float-charge voltage will cause considerable charge current all the time, and boil the cells. What normally limits charge current is the battery voltage rises to the charge voltage, and current flow ceases. It takes a lot of current to get a 10V battery up to 13.2V.

Gilligan


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## Professor (Sep 12, 2006)

Gilligan said:


> Well, I guess theres an exception to every rule- I used to leave mine hooked up all the time, but found (twice now) that my fluids were low (plates exposed), and the water is bubbling- all the time. It appears my charger is boiling my batteries. Maybe I have a dysfuctional three stage charger?


You either have a malfunctioning converter or one or more of the battery cells is shorted.
When a cell shorts out, the battery effectively becomes a 10V battery. Even the modest 13.2V float-charge voltage will cause considerable charge current all the time, and boil the cells. What normally limits charge current is the battery voltage rises to the charge voltage, and current flow ceases. It takes a lot of current to get a 10V battery up to 13.2V.

Gilligan








[/quote]

Well done Gilligan, I can see that you have been paying attention in our campfire discussions.


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