using the house battery to start a 2021 interstate

[Matagorda]

Not sure what happened. We have the 2021 interstate in storage and plugged into 20 amp house power. Today I when by to check on it and run the sprinter (did this a couple of weeks ago and it was fine) and then opened the door the dash was flashing weird stuff like read the manual before you start the unit. After trying to start the dash went completing out and black.

The main control panel show the starting batter was 6 volts and the house battery 13.4 volts. I jumped the unit and let it run for an hour and the starting battery is now showing a little over 13 volts.

I read the manual was not able to learn how to use the house battery to start the sprinter.

Anyone have the same thing happen and any ideas?

[uncle_bob]

Hi

Is your 24 GX a Lithium or a Lead Acid version? That may impact what's what in terms of how the hookup works. The "old" answer was a "boost" switch on the dash. No idea if that applies to yours or not.

Bob

[Hawk-ination]

Read about this happening or similar situations with the newer chassis. Do not have any answers though, just to say it’s not just you I’d say. Might just be a battery issue though. They do not always perform correctly or can get damaged as a new/er battery. We see enough as a battery distributor where we need to replace them, and sometimes it’s not the battery that was at fault.

One thing to know if you didn’t read it is their are specific things to do when jump starting our Sprinters, older models and the new. I haven’t looked at the instructions yet, but you want to make sure you follow the manual and/or find out what specifically you are to do and not to. I would assume it has to do with sending current to the computer and/or systems and causing damage. Wish I had the specifics to comment on, but I’ve just come across it in our business and reading and putting that reminder in my head that if we have to jump it, make sure to find out what process you are to follow. Maybe someone will comment as to the procedure who knows more than me.

[Matagorda]

Originally Posted by uncle_bob

Hi

Is your 24 GX a Lithium or a Lead Acid version? That may impact what's what in terms of how the hookup works. The "old" answer was a "boost" switch on the dash. No idea if that applies to yours or not.

Bob

My is a Lithium set up for the House battery, in searching the net I saw that the earlier units a boost button on the lower left side of the steering wheel. My does not have this.

[Ilguy]

My understanding is that if your rig is equipped with the Lithium tech package, you lose the ability to jump start your chassis battery from the house Lithium. There are specific terminals under the hood designated for jump starting the chassis battery.

[uncle_bob]

Hi

A starter motor pulls a lot of current. The typical RV lithium isn't set up for that sort of thing. Dropping the "jump start" capability with Lithium would not be a big surprise.

(Yes, you can find a *lot* of YouTube videos of folks starting their car / truck with this or that Lithium gizmo ... how wise this is ... who knows )

Bob

[Boxster1971]

Actually lithium batteries are capable of providing higher current than lead-acid batteries.

The newer Interstates don’t have the boost button because it was part of a battery connection relay system than would routinely connect the coach and chassis batteries for mutual charging. You don’t want to interconnect lead-acid and lithium as a part of normal charging because of differing charge voltage profiles. The lithium equipped Interstates have a new separate system to charge lithium coach batteries from Sprinter alternator. Likely an adjustable DC-DC system.

[uncle_bob]

Originally Posted by Boxster1971

Actually lithium batteries are capable of providing higher current than lead-acid batteries.

The newer Interstates don’t have the boost button because it was part of a battery connection relay system than would routinely connect the coach and chassis batteries for mutual charging. You don’t want to interconnect lead-acid and lithium as a part of normal charging because of differing charge voltage profiles. The lithium equipped Interstates have a new separate system to charge lithium coach batteries from Sprinter alternator. Likely an adjustable DC-DC system.

Hi

The term "lithium battery" covers a wide range of chemistries and cell construction methods. Some cells structures can deliver massive amounts of current. Others not so much. Some chemistries are happier with surges than others.

What mainly limits things in the RV batteries is the BMS. It simply is not designed to handle massive currents. It shuts off to "self protect". If you have one of a set do this, the other(s) will quickly follow.

Bob

[Ken G]

My Sprinter based ERA had a boost button in the center of dash below radio. In sub freezing weather once I had to use it as the chassis battery didn’t have the voltage to “glow” and subsequently crank. First I started generator, let it run a few minutes, then I pressed boost button which has the effect of jumping the chassis battery after a couple of minutes of “jump” I turned on the ignition and let it glow then started the engine only then did I release the boost button. It seemed to me that the sprinter chassis had some parasitic drain on battery so after that I was more careful about starting every few weeks.

[Zach05855]

While in storage I always keep a C-Tek battery maintainer on the jump start poles under the hood, and I always carry a small lithium jump start pack with us just in case.

[uncle_bob]

Hi

Indeed this whole "chassis battery dies" thing seems to be what has driven them to putting a solar panel on the chassis side of things. If you are out in the sun, it should do a pretty good job of keeping things topped off. If you store indoors (as we do) it isn't much help ....

Bob

[Zach05855]

There is always the chassis battery disconnect switch just above the accelerator pedal, that is available to cutoff the battery