Chassis battery issues

Two new group 36 batteries fixed it.. the old batteries failed the high rate discharge test, neither battery would give more than 200 AMPs for over 10 seconds, before the voltage dropped below 9 Volts.

Some times you simply must do the right tests first.

the coach would charge the batteries OK but the batteries were sulfided until they simply would not hold the charge.

cbr46 wrote:

Tom/Barb wrote:
the coach still cranks slow,

voltage to the starter is 13.5 volts while cranking(hot), 9+- when cold.

when hot it pulls 450 amps when cold it pulls 650 amps

What kind of oil and viscosity in the motor?

Best,
- c bob

Delow 15W40

Tom/Barb wrote:
the coach still cranks slow,

voltage to the starter is 13.5 volts while cranking(hot), 9+- when cold.

when hot it pulls 450 amps when cold it pulls 650 amps

What kind of oil and viscosity in the motor?

Best,
- c bob

pianotuna wrote:
Hi,

So are the chassis batteries charging on shore power?

Yes..

And the 8.3 will crank normal on different battery set. (jumpered)

So the batteries are out and on a charger, we will see how long it requires to charge and discharge them.

Hi,

So are the chassis batteries charging on shore power?

Today I had time to play with it, here is what I found.

the 2 chassis batteries have sat for 3 days with out being hooked to house power, they measure 14.8 volts.

the coach still cranks slow, voltage to the starter is 13.5 volts while cranking(hot), 9+- when cold.

the difference is when it is hot or cold.

when hot it pulls 450 amps when cold it pulls 650 amps, (I have inductive pick up amp meters)

I think it is the starter solenoid having a high resistance it works when hot not when cold.

when the starter pulls high AMPs the voltage drops to 9 +- and the computer senses it and turns on the check engine light, thinking the alternator has failed.

I still may have the batteries checked by the high current draw method to see if they fail.

We were in the same situation as many others posting here, chassis batteries don't charge except while engine is running. Monaco sells a replacement module to fix this but I went with a trickle charger and no problems for the lst two years.

Tony/Barb,
First off, how long have you had the coach? If a long time, has this problem presented itself prior to now? If you've not had the problem before and, this is a new problem, then, something is malfunctioning and, there's no need to ADD any auxiliary charging system to your chassis batteries. You simply need to repair something that's gone bad.

But, if you've not had this coach for long, and you just noticed this problem then, you need to learn about your charging system(s). This is not meant to be derogatory, just making a suggestion. Just about every coach made for decades, when the engine is running, will charge both chassis and house batteries. Different manufacturers, do it in different ways.

But many manufacturers have failed in the past, and, even some presently, to setup a charging system for the chassis batteries while on shore power. Winnebago and Itasca did just this up until around, late '05. In the '06 and later versions, a "Trik-L-Start" system was installed at the factory to keep the chassis batteries topped off while on shore power.

So, if you study your system(s) and find you have absolutely no chassis battery charging system in place while on shore power, then that's when you need to look into the many that are available. I've read of a newer, more modern replacement for the Trik-L-Start called the "Amp-L-Start". I think that's what it's called. It's supposed to be better than the previous version. Since I was not aware of any of those when I did mine, I simply bought a Napa, three stage charger and permanently mounted it inside the coach in a hide-a-way spot and hard wired it directly to the 110VAC circuit breaker panel and, then hard wired the 12VDC output side to the positive and negative terminals.

Now, my chassis battery charging system is completely separate from the Inverter/charger charging system of the coach batteries. Not that it needs to be, I just wanted it that way.

Also, one of the things you may need to look into is, is there a possibility of short somewhere in the chassis battery system that's drawing them down while being parked for extended periods of time? Again, just a suggestion.

Scott

wny_pat wrote:
My Diesel Pusher, like many others, doesn't charge the chassis batteries while on shore power. I added a Trik-L-Start

. It keeps my chassis batteries charged, plugged in or not, but doesn't kill my coach batteries.

My coach, like many others, doesn't charge the chassis batteries while on shore power. I added a Trik-L-Start