Understanding Charge/Boost button

[sharonbus]

We've recently bought our first motorhome--a 1988 Foretravel Grande Villa. Having lots of fun getting to know the details. On the dash is a two way switch (off in middle) noted as Charge/Boost. When the dealer was driving with us he had trouble starting the RV and pushed the switch. He said it uses both batteries that way. We usually have to use the switch to get running after sitting for a day or two.

In the manual I read the following: "It is recommended that once a month both engine and coach batteries be fully charged. Due to their nature, lead-acid batteries will discharge if not used and recharged.

With the dash mounted battery booster on both batteries can be charged by the built in charger..."

If we're using the motorhome regularly (starting it several times a week), is this something we need to do monthly or do the batteries charge themselves when we drive, like a car would do?

I know it's a really basic question, but not sure how to use this button properly, or if it's normal to need it for regular start ups? Thanks.

[wa8yxm]

Two comments:
First: If the motor home sat long enough without a battery charge this can run the battery down since there are some things always on, Like radio memory, ECM memory and such, in all modern vehicles. Not like the old says when OFF was, well.. OFF.

Second: STARTING batteries... Generally do not like being run down too far.. If you get them to the "Vehicle will not start" point.. you often need to replace them.. This, however, is on cars.. A motor home engine is kind of large and thus it's starting requirements are larger so you may get lucky here.

DEEP CycLE batteries (like the GC-2 golf car battery often used in pairs for house batteires) also do not like being run down below half full.. but the odds of recovery if you do it.. MUCH HIGHER.

Facts:

I accidently ran my house batteries down several times in the 9 years they lasted, This was due to several things,, A tripped breaker (couple of times) not powering the converter.. And several times I pulled the stupid plug. to the converter and did not figure it out for like 3 days. And then usually at 3am or there abouts..

I also ran the chassis down a couple times leaving the headligts on (Beeper does not).

But all of them lasted 9 years.

One time the isolator failed to isolate, so I killed ALL the batteires, could not even start the generator.. had to get one of the small batteries off wife's scooter and used it to jump start the ONAN, by the time I got the scooter back together and the cables put away and traffic cleared (I was in a parking lot) I had enough battery power to fire up the main engine and go shopping.

I did not kill Generator till I was enoute campground and shore power though.

[gbopp]

Get all your batteries checked, they may need replaced.

The 12 Volt Side of Life is very informative.

Trik-L-Start is an option to keep the starting battery charged if, your RV is not equipped with a similar charger.

[MrWizard]

Boost mode jump starts the chassis/engine drive train batteries, using the house batteries

Charge mode allows the RV charger~ converter to also charge the engine/chassis batteries while parked and plugged into shore power

It's possible you need new chassis/engine batteries, they should not lose charge in just a few days

[wolfe10]

With your coach, the alternator charges BOTH chassis and house battery banks.

The 120 VAC converter charges only the house bank. With the boost switch on (yes, it controls a constant duty, not intermittent duty solenoid on the Foretravel) the converter will also charge the chassis batteries.

You should hear the solenoid "click" when the switch is turned on and chassis battery voltage should very quickly match that of the house bank.

BTW, what chassis?

[mikeh449]

bad engine battery have it checked should not go dead that soon check charging system too

[1492]

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