Chassis Battery Issue

c21bill

Advanced Member
Joined
Nov 1, 2024
Posts
35
Location
Central Point
We have our Swift in winterization storage using the 30 day protocol. After a month I activated the Lithium batts and all good with those, showing 53.6 volts. Problem was the chassis batt was down to ~ 9v. Couldn't find anything that was left on. Anyone have any ideas? Also, I thought the button below the steering wheel was for emergency starting off the Lithium Batts but it did nothing. I called Jayco and they informed me that they didn't provide the emergency start function on the Lithium models and the button was to activate the automatic engine start. Does anyone know that procedure?
 
53.6 must be the amount of solar coming in, not battery voltage. If you had a battery with 53 volts, I would run away.
The white button below the steering wheel is for using the house batteries to start van. That said, you cannot use lithium batteries for starting and engine. They probable added it by mistake.
Remote starting of the van is done by the key fob. If you have that option from Ram, you should have a button on the remote with a X2 on it. By pressing twice, the van will honk and start-up.

Taking so long for this to be answered shows how little members this forum has. Unfortunate.
 
You are incorrect sir, the Lithium models have a 48v house battery and the max voltage on those is 54+. They are also equipped with a 48v air conditioner which runs directly off the battery instead of thru the invertor. On Li models the button under the steering wheel is to turn on the auto start feature in the event of low house battery voltage, Li models are not equipped with a provision to start the engine with the house batteries.
 
53.6 must be the amount of solar coming in, not battery voltage. If you had a battery with 53 volts, I would run away.
The white button below the steering wheel is for using the house batteries to start van. That said, you cannot use lithium batteries for starting and engine. They probable added it by mistake.
Remote starting of the van is done by the key fob. If you have that option from Ram, you should have a button on the remote with a X2 on it. By pressing twice, the van will honk and start-up.

Taking so long for this to be answered shows how little members this forum has. Unfortunate.
I would suggest that it is not that there are too few members here and instead there is not a lot of Swift owners that have a deep understanding of the unique electrical setup in these units. The Swift units have a series setup of the batteries (internal) that provides 48V (commonly measured in the low 50's) and as I have read from others a second alternator off the engine for them. (at least some of the Swift's, I am not sure if they all have this).

c21bill ; I would suggest to contact Jayco and see if they will provide you with a DC schematic for your RV and if they will, feel free to share that here and then I could provide you with more specific guidance. What I suspect is similar to the Class C (and some A's as well) motorhomes in regards to the engine starting battery where there is commonly something draining it even when on shore power and this drain is separate from the coach power (batteries). Many will simply install a small ~5 amp marine (waterproof) 12V battery charger\maintainer for the 12v chassis battery which would be powered anytime the RV is connected to shore power or running off of the generator. ~CA
 
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Actually I found that my chassis battery was bad. Fortunately Costco had a decent replacement for $180. Sadly I don't have shore power where my rv is stored so my procedure is to put the house batteries in 30 day storage mode then about every two weeks I start the engine and run it on high idle for a while. Seems to be working out ok. I don't drive it because I have the insurance in storage mode.
 
Actually I found that my chassis battery was bad. Fortunately Costco had a decent replacement for $180. Sadly I don't have shore power where my rv is stored so my procedure is to put the house batteries in 30 day storage mode then about every two weeks I start the engine and run it on high idle for a while. Seems to be working out ok. I don't drive it because I have the insurance in storage mode.
Not having specific knowledge of a Swift motorhome, with many Class C's & A's it is common to find a drain exists on the chassis battery that will pull it down to the point where it cannot start the engine commonly reported to happen after a couple of weeks or more. When this happens, damage also occurs to the battery prematurely due to being fully discharged (or close to that).

I would suggest to check the chassis battery voltage each time you are at the RV and prior to starting the engine so you can see if the chassis battery voltage is becoming lower and lower and if so (or perhaps to be pro-active) then I would suggest to remove the neg battery cable whenever the RV will sit for more than a week or so (or install a terminal disconnect). ~CA
 
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Good suggestion. I will pick up a voltage meter because in order to read the voltage in the rv I have to turn on the house batteries in order to get the readout on the Firefly screen. I prefer to leave the house batteries in storage mode until it is time to turn them on and top off. Life would be simpler if I had shore power.
 
Regarding the Swift setup, my suspicion would be that the 48V LifePo4 battery system only provides power when the inverter system is turned on, which would provide for 120V, 12V and direct voltage (48V) for the A/C. With that in mind, and with my understanding that all RV's are required to have an active CO / Propane leak detector enabled, that the detector stays powered via the 12V chassis battery even when the house battery system is in storage mode. I would also suspect this is true for other components such as the steps, radio, lights, and anything that has power whenever the house batteries are in storage mode. The CO\Propane leak detector should be a very low electrical drain, but in combination with other components could be enough to drain the chassis battery over a few weeks of time. ~CA

Again, just a suspicion I have that would make logical electrical sense, not to be confused with me actually knowing the Swift electrical setup for sure.
 
You are correct in that the invertor does need to be turned on. It has to be off when in storage mode or the Lithium house batteries will get sucked down fast. It happened to me when the rv was new because the dealer did not fully explain the shut down procedure during the walk thru. No surprise there!
 
Did not realize it was a lithium version since the actual model was not mentioned. Only that it had lithium batteries. (Like my unit)
Yes that makes sense.
 
I wondering if there are changes between year model because I have a 2022 Ethos 20TL and my chassis battery has a separate solar panel and controller to keep it charged up. Now of course if your van is store indoors or covered it won't matter, but if not I'm wondering if your have the Renogy Wander as well.
 
I know that the Li version because of this trickle charger, they don't do the emergency start from house (lithium) battery. Ive gotten a NOCO Genius 5 and installed directly to the chassis battery cable so I can plug the NOCO in from the outlet in the van if I need to charge the chassis battery. I also have NOCO GB40 to jump start it. Ive had to do this because I have to store mine a lot since I have MS and get sick here and there. Just some ides.
 
But I'm guessing where your van is stored covered or indoors. The separate solar panel and controller should trickle charge it if it's getting sun. Now one other thing if the van is covered then the controller itself will be drawing (while a small amount) from the chassis battery too. I haven't look myself at the chassis battery for the connection from the solar controller, but I would assume it's fused. Might be a good idea to remove the fuse so the controller isn't another draw on the chassis battery.
 
We are in winterization storage so the house batteries are completely shut down. That includes the solar system. The only thing live is the chassis battery. I did consider disconnecting it but it is a total PIA to access it.
 
I have the Ethos T Li and it has the solar charging for the chassis battery, the Go Power screen that is with it is on at all times so I can check the voltage when parked without turning on the house battery system.
I was able to get the schematics for my van from Jayco and all the 200 watt solar panel arrangements that are available with different ethos camper styles. I am sorry I can’t figure out how to attach them to a post . All I did was ask a customer service representative.
Good luck
 
I have the Ethos T Li and it has the solar charging for the chassis battery, the Go Power screen that is with it is on at all times so I can check the voltage when parked without turning on the house battery system.
I was able to get the schematics for my van from Jayco and all the 200 watt solar panel arrangements that are available with different ethos camper styles. I am sorry I can’t figure out how to attach them to a post . All I did was ask a customer service representative.
Good luck
I'm a bit surprised to hear that. On my 2024 20TL the Solar goes to the house batteries and needs to be turned off prior to shutting down the batteries for winterization storage. Just confirmed this with Jayco customer support. Perhaps you have a different year coach which was set up differently.
 
I have a separate panel and controller for chassis battery top-up. 200 watts of solar panels for house , but these do not even keep up with the fridge load in good sunshine.
 

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