Lithium Swap and OEM Battery Mode Solenoid Question

[dashriprock1]

I purchased lithium batteries to replace the house battery bank on my 2017 Winnebago Era 170A. I also purchased a dc-dc charger for lithium to go between my starter battery and house batteries. Will I need to delete the OEM battery mode solenoid and battery relay from the circuit? Thank you.

[eyecando]

You don't want the solenoid to connect the two batteries together during routine operation because the low impedance of the lithium battery may cause the alternator to provide excessive current and damage it.

You didn't indicate what chassis you have, but the easiest thing to do would be disconnect the wire that picks up the solenoid. This will be a small wire probably 14 or 16 gauge wire that connects to the solenoid. If there are two small wires, one of them would be the connected to ground. This will also eliminate the ability to tie the battery banks together to start the vehicle in the event the chassis battery fails. Or you could disconnect the ground wire if present.

The DC to DC charger would connect across the two large studs on the soelonid. The stud that connects to the chassis battery would connect to the DC to DC charger input. The other large stud would connect to the house battery.

[powercat_ras]

Agree with eyecando's post. One additional thing: if your Era has a feature that allows the chassis battery to be charged from the coach battery system when you are parked and charging from the coach solar charger or the coach AC to DC converter charger you may want to do a more involved change than to just disconnect the control wire on the battery isolator solenoid. There may be a Winnebago OEM battery isolation manager (BIM) module in which case you would find and disconnect the ignition_on wire feeding the BIM, that way you would not lose the Coach -> Chassis charging function.

[Morich]

This would be the wiring for that section of your RV but be aware that there may have been after market items to connect the two battery groups together, so watch for anything like that iof you are not first owner.

https://www.winnebago.com/Files/File.../000027700.pdf

Page one gives the layout and where to find the mode solenoid, while page 3 gets down to the detailed wiring. Looks like you have the three wire solenoid and that means wire LR is the control wiring from the dash switch or ignition hot. Your system feeds power in on LR and through coil and uses an internal connection to get to the ground via the metal case. Removing LR from the small center post will disable this connection, both for the "boost" use and also foring charging the coach battery as we drive.

The item sometimes added is like a Trik-L-Start, etc and putting it on the solenoid or at the batteries are the two common places to add this mod. Small black box with three single wires to connect to each battery.

Unless there is some reason, I would not disconnect the disconnect relay as it is not involved in anything other than disconnecting the battery when stored.

[dashriprock1]

Excellent information. Exactly what I was wanting to know. Thank you!

[Morich]

Just as another option to consider?
If we wanted to leave the boost feature as an option for any emergency that showed up, it would be pretty simple to just add a switch to kill or make good the path to operate the solenoid.

One would want to make it someplace where it would NOT get turned on accidentally.
But if one put a small switch somewhere like under the passenger seat and made sure it was ONLY used when needed, the switch can be as simple as a small toggle or slide switch. Maybe mark it as emergency use only?
It only has to be big enough to carry the very limited current to operate the solenoid coil. Note how small the control wiring is. Most any size toggle or slide switch will do for that current.
You would do away with one objection to removing the solenoid operation but would still maintain the ability to "boost' a weak chassis battery if it was ever needed.
I have not looked at your RV setup but we have needed the boost switch when the radio was used and it was left on the chassis side battery , rather than switched to the coach side.

[dashriprock1]

Originally Posted by Morich

Just as another option to consider?
If we wanted to leave the boost feature as an option for any emergency that showed up, it would be pretty simple to just add a switch to kill or make good the path to operate the solenoid.

One would want to make it someplace where it would NOT get turned on accidentally.
But if one put a small switch somewhere like under the passenger seat and made sure it was ONLY used when needed, the switch can be as simple as a small toggle or slide switch. Maybe mark it as emergency use only?
It only has to be big enough to carry the very limited current to operate the solenoid coil. Note how small the control wiring is. Most any size toggle or slide switch will do for that current.
You would do away with one objection to removing the solenoid operation but would still maintain the ability to "boost' a weak chassis battery if it was ever needed.
I have not looked at your RV setup but we have needed the boost switch when the radio was used and it was left on the chassis side battery , rather than switched to the coach side.

Yes, I have had to use the coach battery bank to start the van after draining the starter battery as well. I carry a Noco jumpstarter that works well so if it comes down to it, I think I will be ok if I need to override the starter battery. Thank you for the information.

[dashriprock1]

Originally Posted by eyecando

You don't want the solenoid to connect the two batteries together during routine operation because the low impedance of the lithium battery may cause the alternator to provide excessive current and damage it.

You didn't indicate what chassis you have, but the easiest thing to do would be disconnect the wire that picks up the solenoid. This will be a small wire probably 14 or 16 gauge wire that connects to the solenoid. If there are two small wires, one of them would be the connected to ground. This will also eliminate the ability to tie the battery banks together to start the vehicle in the event the chassis battery fails. Or you could disconnect the ground wire if present.

The DC to DC charger would connect across the two large studs on the soelonid. The stud that connects to the chassis battery would connect to the DC to DC charger input. The other large stud would connect to the house battery.

Hey, I tried what you suggested and it works killer! thanks!