chasis batteries

[rex unicume]

Hi all
I have a 1997 Patriot with the 3126 Cat, I think that is the number, 300hp engine.
Does anyone know what equipment draws from these batteries?
They must do more than just start the engine.
Do you think there is a continuous draw from other sources?
They seem to need a lot of care.
Cheers
Rex

[Gerald Farris]

Rex,
The chassis batteries start the generator and engine on your coach. They also power the normal chassis items like dash A/C, headlights, and wipers. The simple way to look at it is that if your car has it, the chassis batteries power the same item on your coach.

Gerald

[rex unicume]

Thanks Gerald
Much appreciated
Cheers
Rex

[Steven Hoffman]

Rex

I found my Kwickee steps and a Carefree over the door power awning tap into the chassis batteries.  I think the hydraulic leveler is also powered off the chassis batteries.  Probably some parasitic loads from ECU etc also.

You want to make sure you have a means to keep them charged.  Echo charger or "Bird" system are two ways.    

[Richard And Babs Ames]

We hav the 3126 Cat engine in our 1997 Patriot and in our case it is the 330 HP version. We found out after Hurricane Charlie that the chassis batteries are not charged by the inverter charging system but required to be up so the generator and other functions like the engine electronics and a couple other items can function. We installed an echo charger and the problem was solved.

The Patriot has a Battery cut off solinoid that is controled by a switch at the front door that reduces some of the parasitic load.

[rex unicume]

Richard
That helps a lot.
Is the echo charger installed separately beyond the inverter/charger?
Sounds exactly what my problem is.
The house batteries charge when plugged in but the chassis batteries go dead.
Are these chargers easy to find and have installed?
thanks tons again.
cheers
Rex

[Keith Oliver]

Rex:

On my Contessa, 330 hp Cat, the ECU draws a continuous ~2 amps, thus depleting the chassis batteries unless there is a functional charging system in place.  In 98, the system came with an echo charger, but of course, by 2011, when I got the coach, that was well past its sell-by date and was non functional.  I put in a "BIRD", a Blue-Seas brand relay that combines the house and chassis batteries for charging, but keeps their loads isolated from one another.  No subsequent problems.  The BIRD was easily found at an RV supply store in Indio, so you should have no trouble finding one.  As the brand name implies, Marine stores will also supply that item.

[rex unicume]

More great info.
thanks
Rex
Cobble hill bc

[Richard And Babs Ames]

http://www.xantrex.com/documents/Accessories/Auxiliary-Battery-Charger/Echo-charge-OwnerGuide(445-0204-01-01).pdf The Echo Charger mounts to the area arround the batteries and acts as a one way connection between the two battery banks so the chassis batteries pick up the charge going to the house batteries.

Beaver did to to the BIRD unit that does the same job for about three times the cost and is more complicted to me. You can also use a "Battery Tender" if you stay hooked to shore power a lot.

[rex unicume]

What is the ECU

[David T. Richelderfer]

http://en.wikipedia.org/wiki/Engine_control_unit

I was thinking Electronic Control Unit, but whatever....  The Allison transmission has an ECU too.  My Avalanche has an EBCM (or something close) - Electronic Brake Control Module.

[rex unicume]

Thanks
Didn't know there was so much draw on the chassis batteries.
Cheers
Rex

[Gerald Farris]

Rex,
If you are talking about the draw on the chassis batteries when the coach is not being driven, that draw is from the Caterpillar ECM (engine control module). The ECM has a continuous draw to maintain its "keep alive memory". This draw will completely discharge your chassis batteries in a week or less if they are not being charged from some source. That is the reason for solar panels on Beaver coaches.

If you do not have adequate sunlight (very cloudy or stored inside), you need to either disconnect the chassis batteries or have an electrical source to maintain battery state of charge. If your coach does not have an Echo Charger or a "Bird" system, you would be wise to invest in one. If this is just confusing you more, give me a call (713-254-4156), and I will explain the electrical system and your battery charging options to you. I will be in the Eastern Time Zone for the next week.

Gerald    

[rex unicume]

Gerald
That would be great, thank you so much.
I will call soon.
Cheers
Rex

[Dennis Crawford]

Just to add to Gerald's comments, there is more than the ECM that is drawing down those batteries.  Each item may be small, but when added together can be nearly 2 amps.  The radio, the CB, the propane detector, the Alison, the satellite radio if you have one.  A few days is all it takes.

Dennis