Chassis battery drains while on shore power.

[Foretm]

This is a common problem with the Jayco Class A coaches. I chose to solve it by installing an amp-l-start. It basically connects the house and chassis batteries together when needed to allow the chassis battery to remain charged.

See this thread - https://www.jaycoowners.com/forums/f...tml#post723032

Unfortunately, it looks like these are no longer available. I did find this, but its about 3x the cost of the amp-l-start.

https://inverterservicecenter.com/ec...IaAkWJEALw_wcB

Here's another one.
https://www.defender.com/product3.js...9976&id=605576

I've not used anything but the amp-l-start, so I can't say 100% these would work for you, but they should. You could always go for a battery maintainer and plug that into the 110V in the coach.

[Redhawk 22C]

I have purchased a good battery maintainer.
I do not understand why the chassis battery is discharging, while in storage, or when parked at an RV Park for a month or more. Something must be drawing from it.

[Foretm]

The dash radio, the leveling system, the steps, and others are drawing from the chassis battery.

[Redhawk 22C]

I know that the steps, radio and leveling system draw from the chassis battery. But, they should not be drawing anything when not in use.
I may start disconnecting the battery when parked.

[Foretm]

The radio and leveling system are always on, even when powered off they draw. I'm sure there are others. I'm not saying they should, just the way it is. Long standing issue and we all deal with it.

You can put a battery disconnect if you want, mine stays plugged in, so prefer a charger.

[Redhawk 22C]

I will keep a battery maintainer on it, I guess. The windshield shade runs off of the chassis battery, also, and we use that everyday while camping.
When I park it at home, I'll unhook the battery.
Thank you. 2019 Alante 31V.

[thepaulsri]

It's interesting how there are strong but differing opinions on whether the Jayco class A's chassis battery is supposed to be charged when plugged in to shore power or not. Some say yes and some say no.

Mine is not staying charged and is draining while connected to shore power.

I sent an e-mail to Jayco (motorizedservice@jayco.com) asking if the chassis battery SHOULD be charging and got this answer about my 2021 Alante ... "The chassis battery is charged through shore power. That is possible through the battery isolation manager, also known as BIM. If the chassis battery is not getting charged we can look at the wring to BIM or the component its self may need to be replaced. "

I have not gotten anywhere with my Jayco dealer for warranty service to even look at it. I have tried to look to see if I even have a BIM installed and don't see what I think I'm expecting to see. I don't mind replacing it myself, if it's a matter of replacing an existing device - if I can find it - but not sure I want to try figuring out how to wire it in if somehow it got left out of my rig.

Given all the comments about chassis batteries not charging it seems like 1) my Jayco response is wrong or 2) the BIMs they install are pretty poor and fail frequently or 3) The Jayco designers include a BIM in the plans but the builders 'forget' to install it frequently.

[Robbbyr]

Originally Posted by thepaulsri

It's interesting how there are strong but differing opinions on whether the Jayco class A's chassis battery is supposed to be charged when plugged in to shore power or not. Some say yes and some say no.

Mine is not staying charged and is draining while connected to shore power.

I sent an e-mail to Jayco (motorizedservice@jayco.com) asking if the chassis battery SHOULD be charging and got this answer about my 2021 Alante ... "The chassis battery is charged through shore power. That is possible through the battery isolation manager, also known as BIM. If the chassis battery is not getting charged we can look at the wring to BIM or the component its self may need to be replaced. "

I have not gotten anywhere with my Jayco dealer for warranty service to even look at it. I have tried to look to see if I even have a BIM installed and don't see what I think I'm expecting to see. I don't mind replacing it myself, if it's a matter of replacing an existing device - if I can find it - but not sure I want to try figuring out how to wire it in if somehow it got left out of my rig.

Given all the comments about chassis batteries not charging it seems like 1) my Jayco response is wrong or 2) the BIMs they install are pretty poor and fail frequently or 3) The Jayco designers include a BIM in the plans but the builders 'forget' to install it frequently.

Senecas have had BIMs for years and they do sometimes fail, mine did on my 2014 Seneca. On Senecas they are located near the house batteries, on the newest Senecas they are located in a compartment inside a covered box. So it is possible it would be similarly located in an Alante near your house batteries. The BIMs have been redesigned by the maker (Precision Circuits), I will attach pictures of the old style and the current version so you might be able to locate yours.

[Alante31V]

Back from April, 2022 email to them on our 2021 Alante 31V, got the AMP L START and all good. Thanks FORETM.

==

“It does not charge the chassis battery.

Erish Edmisten
Jayco Motorized Lead Tech
Jayco Motorhome Group
Phone: 800-283-8267 /Fax: 574-825-6091
Email:motorizedservice@jayco.com
903 S. Main St., Middlebury, IN 46540
Jayco| Entegra Coach
Starcraft RV| Highland Ridge RV”

[Foretm]

Originally Posted by thepaulsri

I sent an e-mail to Jayco (motorizedservice@jayco.com) asking if the chassis battery SHOULD be charging and got this answer about my 2021 Alante ... "The chassis battery is charged through shore power. That is possible through the battery isolation manager, also known as BIM. If the chassis battery is not getting charged we can look at the wring to BIM or the component its self may need to be replaced."

Separately, ask them for the wiring diagrams for the 12v electrical system. I did and i've uploaded it. What you'll see is a disconnect (business end of the salesman switch or disconnect in the stairwell) and the auxiliary start solenoid which connects the house and chassis batteries when the switch in the dash is activated to start the engine when you have a dead chassis battery. In my Entegra Vision, which is equivalent to the Jayco Alante, there is no BIM, therefore no chassis battery charging. I added the amp-l-start back in January 2019 and it's been working perfectly since, before that the battery would drain in a few days. They don't make the amp-l-start any longer that I can tell, but I would ask for the schematics for your rig, then check them for accuracy against the coach.

[Vicr]

Those of you without a BIM why not simply add one to your electrical system?

[Foretm]

When my amp-l-start eventually dies, I intend to. The BIM160/225 is an easy replacement for the Aux Solenoid on my coach now. Begs the question, why Jayco didn't put these in originally. I know its added cost, but kind of a big deal that the coach doesn't charge when on shore power. My amp-l-start works fine for now, so not changing it until it dies.

https://www.precisioncircuitsinc.com...ger-Rev7-1.pdf

[Foretm]

Originally Posted by Foretm

I chose to solve it by installing an amp-l-start.

Unfortunately, it looks like these are no longer available.

Looks like RVUpgrades.com picked them up.

https://www.rvupgradestore.com/15-Am...mp-l-start.htm

[craigav]

Originally Posted by Foretm

Looks like RVUpgrades.com picked them up.

https://www.rvupgradestore.com/15-Am...mp-l-start.htm

There price was lower than I expected, then I read:
Quantity in Stock :
Availability: No Longer Available
Product Code: AMP-L-START

[Foretm]

Originally Posted by craigav

There price was lower than I expected, then I read:
Quantity in Stock :
Availability: No Longer Available
Product Code: AMP-L-START

Ughhh.... Apologies... Jumped the gun.

[embeleco]

Originally Posted by Foretm

Separately, ask them for the wiring diagrams for the 12v electrical system. I did and i've uploaded it. What you'll see is a disconnect (business end of the salesman switch or disconnect in the stairwell) and the auxiliary start solenoid which connects the house and chassis batteries when the switch in the dash is activated to start the engine when you have a dead chassis battery. In my Entegra Vision, which is equivalent to the Jayco Alante, there is no BIM, therefore no chassis battery charging. I added the amp-l-start back in January 2019 and it's been working perfectly since, before that the battery would drain in a few days. They don't make the amp-l-start any longer that I can tell, but I would ask for the schematics for your rig, then check them for accuracy against the coach.

I asked for the 12V electrical diagram for my rig some time ago and even thought it included the BIM.. they told me that while on shore power the chassis battery will not charge.

Is that the case even having the BIM?

[Foretm]

Originally Posted by embeleco

I asked for the 12V electrical diagram for my rig some time ago and even thought it included the BIM.. they told me that while on shore power the chassis battery will not charge.

Is that the case even having the BIM?

If you have the BIM, then yes it should charge the chassis battery when on shore power. Asking for the wiring diagram will help to see if you have it or not and help verify. Once you have it, or even before you have it you can look near the house battery area and determine if you do or not. If you have one and its still not charging then it may be faulty, but knowing if you have one or not is the first step.

[embeleco]

Originally Posted by Foretm

If you have the BIM, then yes it should charge the chassis battery when on shore power. Asking for the wiring diagram will help to see if you have it or not and help verify. Once you have it, or even before you have it you can look near the house battery area and determine if you do or not. If you have one and its still not charging then it may be faulty, but knowing if you have one or not is the first step.

My rig is in storage but I'll check next weekend to see if I have the BIM in there or not. As far as the 12v electric schematic provided.. it does have one.. unless the schematic provided is not the one for my rig.

[Foretm]

Gotcha.... would you mind uploading so I can review it out of curiosity? I posted mine in post #50, I want to see the difference between the two.

[embeleco]

Originally Posted by Foretm

Gotcha.... would you mind uploading so I can review it out of curiosity? I posted mine in post #50, I want to see the difference between the two.

Sure.. here it is the one provided.