Batteries Again

[Guest Wayne77590]

Okay! I have searched and read many different ideas on the subject of keeping your chassis AND house batteries charged. here goes my converstation with Winnebago Friday.

I called and talked to a service representative and told him that I have the Parallax 7455BT. My question was: Is it supposed to charge the house batteries and the chassis batteries.

He looked up my model number and my specific coach by serial number and stated that the system I had should charge both the service batteries and the chassis batteries.

I digress here: I have not had a problem with the house batteries maintaining a charge, but after 4 or more days of sitting, and I start the engine, I get "Low System Voltage," and then it will show me 11.4 volts. it only takes a few minutes to get it up past 13.5+

End digress:

I informed the tech of what was happening. He stated that the step must be in the off position as it keeps a steady voltage on the steps when left on. Further conversation and the tech stated that the chassis disconnect must be in the connected position, and the Auxillary Battery switch in the "On" position to charge both batteries. (and be connected to shore power)

Today, I started the engine and after 8 minutes the chassis batteries were reading 14V. I hooked up to shore power and did as the tech stated. Reaching in with an umbrella through the screen openin to turn the step off because I wanted it closed, was a trick, but it worked.

I plan on going back tomorrow or Monday and checking everything and disconnecting the shore power for 3-4 weeks.

I did purchase a Battery Minder 12248, which will charge all batteries when connectied correctly. That will be my next project as my knee replacement heals.

Any comments on all this will be considered. Experience is alway helpful.

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I have posted this same information on another Winnebago specific thread and I received one answer. That being that the high current draw in heating the spark plugs is the cause of the low system voltage warning after starting the engine.

[wolfe10]

Wayne,

A VERY strange response from the Winnebago group to low battery reading after starting-- heating spark plugs??? Some systems DO have a delay before cutting on the alternator to allow the engine to start and run for a short time before loading it with the alternator. You could check with your chassis maker to see if this is the cause of the short-term low voltage reading on your coach.

And I suggest you follow Winnebago's "secret sauce receipt" for what needs to happen for your converter to charge both battery banks.

Then, after 3-4 days, VERIFY IT. Just check voltage at the batteries with a digital voltmeter. House and Chassis should be the same and 13.0-13.5 VDC.

Brett Wolfe

[Guest Wayne77590]

Oops! Need to clarify that the response for low reading after starting was NOT from Winnebago. Another forum specific to Winnebago is where it came from.

Thanks Brett. I do plan on checking it tomorrow and if the reading is good I'll unplug the shore power for a few weeks and then do it all over again. As soon as I can, when knee is ready, I'll hook up the Battery Minder 12248.

[wolfe10]

Oops! Need to clarify that the response for low reading after starting was NOT from Winnebago. Another forum specific to Winnebago is where it came from.

Thanks Brett. I do plan on checking it tomorrow and if the reading is good I'll unplug the shore power for a few weeks and then do it all over again. As soon as I can, when knee is ready, I'll hook up the Battery Minder 12248.

Wayne,

IF you have shore power where you store your coach and your converter maintains (once FLOAT LEVEL is reached)battery voltage between 13.0 and 13.5 VDC, just leave it plugged in. If higher, it will probably over-charge the batteries-- a symptom is the use of excessive water in the batteries.

And if both battery banks are charged from the converter (as was suggested), why fit the Battery Minder at all.?

If your converter maintains voltage higher than that, another option while on shore power is to buy a HD timer from Lowes/Home Depot. Plug the converter into it and let it run for an hour or so a day.

Brett Wolfe

[Guest Wayne77590]

Brett,

How fair would that be to my pocketbook to have a $129 Battery Minder and not use it?

However, I do like your idea of a timer. The Battery Minder 12248 is also a desulfator.

As soon as my knee replacement (I had surgery on Sept. 15) is good enough for me to crawl around, I'm going to meter the voltages to see if things are operating as Winnebago stated they should.

I'm dissapointed in myself for not thinking of the timer. Darn!