Plugging into 110 with coach batteries removed

[Nonno]

Recently due to bad cells, I removed my 2 coach batteries. Also I disconnected the negative lead on my engine battery (it's fully charged) for the winter. Question - Am I correct in my thinking that when I plug into 110V even the 12V items will operate?

[Nonno]

Recently due to bad cells, I removed my 2 coach batteries. Also I disconnected the negative lead on my engine battery (it's fully charged) for the winter. Question - Am I correct in my thinking that when I plug into 110V even the 12V items will operate?

[John Hilley]

Yes, you are correct, the 12 volt lights and etc. will operate.

[Nonno]

Thanks John. I wanted to be sure I wasn't fixing one problem and creating another.

[Charles99]

I also have a 37B. My batteries didnt last long. It is because the converter is a cheaper model and it over charges the batteries, and the 12volt batteries are in parallel, when one goes bad it will kill the other. I changed to two 6 volts in series. They wil fit in the same place, and dont require water near as much as the 12's. You also have a switch on the wall by the steps that will turn the batteries off, but as long as the coach is pluged in, the converter will run the 12v equipment. You can also get 5 - plus years out of 6 volt batteries.

[Nonno]

Charles,

I'd be interested in getting more info about the 6V batteries. What brand / model# are they? Why only 2 instead of 4? Could you explain or possibly send a picture of how you connected them.

Thank you

[Y-Guy]

Charles thanks for your post, I've always run dual 6-volt batteries in all my trailers so when I saw my new Sightseer only had two Group 24 batteries I was a bit amazed. I figured I would give it a go with the 12-volt ones but I think I'll be upgrading sooner rather than later.

Bob - I've had good luck with the Interstate brand of batteries, or the Trojan 105s. In my case I can't fit 4 batteries, but it looks like I could easily replace the 12-volt ones. Most 6-volt batteries are a bit taller than the 12-volt siblings.

One of the best sites to help me understand batteries is The 12-Volt Side of Life - I always keep that one bookmarked.

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Charles99:
My batteries didnt last long. It is because the converter is a cheaper model and it over charges the batteries, and the 12volt batteries are in parallel, when one goes bad it will kill the other. </div></BLOCKQUOTE>

I have a 2005 38R and my batteries are in great shape. I've only had to add water once in 23 months. I ordered the coach from the factory and it didn't sit on a dealers lot for months or was taken to shows. I also should mention we've spent 372 nights in the coach since January 25, 2005.

Tell me about the cheap converter I have.

-Tom
parked in Crystal River, FL until April

[Charles99]

Yes I will be glad to post some pictures. Give me a few days, we are leaving for Islamorada FL Christmas Day. We will arive there on the 26th. I will post some pictures then.
In my 2004 adventure 37B. I have a parallax 7400 without the float timer.
Parallax 7400 instructions

The unit operates at 13.8 volts all the time. If you are not using your 12v stuff, it will tend to over charge the batteries and they will start to off gas as they over charge. The 12 volt batteries cant handle this as good as the 6volt golf cart batteries. The 6 volts are designed for this kind of abuse. As for only two: Two 6 volts have the same stoage capacity as two 12's in parallel, and that is all I have room for. I did have to install longer (all thread)rods to hold the batteries in place. You can buy that at Lowes.

[Tom N]

I just checked the charge voltage. My 7400 float charges at 13.5v. My 7400 must have the T option. The amperage is what tapers down as the batteries reach full charge. The 7400 tapers to a few hundred milliamps when the battery(s) are at full charge. My 7400 has never overcharged my batteries.

Winnebago may be using the T option 7400 in the more expensive Itascas and the non T option 7400 in the cheaper Winnebagos.

I'll pull the cover and check my 7400 this week.

[DonavonP]

I checked my converter. It's a 7400 series model number 7455 (no T and 55 amps). It says it charges down to .5 amps so I popped one of the covers to check the water level. It was ok still from the last fill about a month ago but as I watched the liquid, I could see an occasional buble so I can see where the converter is going to boil it dry.

I unplugged the MH and attached my Battery Minder.

Thanks for starting this thread Bob Russo and contributors Charles 99, YGuy, and Tom N.

Best RV site on the web.

[Nonno]

I'll physically check tomorrow but looking at the component info sheet provided by Winnebago, my converter model is a 7455BT.

Not sure if this makes a difference but mine is an 05 on an 04 chassis. Workhorse manufactured 6-04, Winnebago manufactured 8-04 and in service to me 9-04.

[Nonno]

Just looked at the converter. Serial #7400 Model #7455T. Input 105-130 VAC, 60hz, 975 Watts. Output 13.6 VDC, 55 amps. Average charge rate .5 amps, max charge rate 45 amps.

Having said that, what does it mean? Will it boil over the batteries? Is this a reason for bad cells occuring? Are 2 6V in series the best solution?

So many questions what should one do?

[DonavonP]

I didn't like all the wires, battery charger, and clutter around the step/batteries so I put a Intermatic 3 prong plug timer in the recepticle that the converter plug into. I moved the plug a few inches to make room for the timer (easy to move - two screws. Loosened one and removed one, turned it away from the converter and rescrewed.) Now the timer runs the converter for 2 hours a day, replenishes the coach and chassis batteries, and is shut down for 22 hours. I have a wire from the coach battery positive to the chassis battery positive.

If this doesn't work out, I'll post.

Bob R. I can't answer your question on why your cells went dead. You may just have been unlucky.
I'll probably go with 2 golf cart batteries when the present ones croak.

While you don't have batteries in your coach, make sure the red wires aren't touching the frame. Put a baggy over them or something.

Intermatic link to T311 3 prong timer $ 8.00 at Menards