So I spent the weekend winterizing and buttoning up the unit for the winter and have a question regarding the batteries. I understand that on my 2018 m2 ts chassis that I can leave it plugged into my 110 30 amp service that both the chassis and coach batteries will be be monitored and charged accordingly.
My question being is it proper procedure to leave both the 12volt cut off switch at the door and the inverter both turned on or off for the battery charging to take place?
I did do a search on the subject but could never really find the answer, so pardon me if the topic has been discussed. I just wasn’t able to find it.
The converter that charges the house battery will not charge the chassis battery. There is a relay/solenoid that connects the chassis battery to the coach battery which is energized when the ignition is on. This allows the alternator to charge the coach battery.
I modified my relay so I could energize it while camping when I see the voltage drop off on my chassis battery (I have a cigarette lighter voltage display). I installed a wireless relay to energize the coach relay so it is pretty slick.
The only reason I need to keep the chassis battery recharged while camping is because I tap off it for a USB charging station to recharge things.
Many people add trickle chargers for the chassis battery to do what you are trying to do. When my unit sits I use a cheap 10 watt solar panel to keep the chassis battery trickle charged.
Lastly, turn the inverter off as there is no reason to keep it running. Just a waste of power.
__________________
Jim
Retired electronic technician (45 years in the field)
2017 Greyhawk 29W (solar & many other mods)
wife (maybe I should have given her top billing)
This may not apply since I have another brand Motorhome but it is on a M2 Freightliner chassis. But my rig has a BIRD relay that does in fact charge my chassis batteries while on shore power. It is an easy check with a meter.
According to my manual there is a “bi-directional Charge relay” that will charge chassis batteries once coach batteries are sufficiently charged. It doesn’t say whether the inverter or 12 volt disconnect switch needs to remain on.
I dont think it will matter if the disconnect is off or on. The converter is powered from the 120 side and then runs 12 DC to the positive side of the battery disconnect where it then runs to the batteries. The Seneca comes with a isolation manager between the chassis and coach and will automatically keep both sets of batteries charged.
Personally I only turn off the inverter and leave the disconnect on.. I have only turned the disconnect off a dozen times or so in 2 years.
I dont think it will matter if the disconnect is off or on. The converter is powered from the 120 side and then runs 12 DC to the positive side of the battery disconnect where it then runs to the batteries. The Seneca comes with a isolation manager between the chassis and coach and will automatically keep both sets of batteries charged.
Personally I only turn off the inverter and leave the disconnect on.. I have only turned the disconnect off a dozen times or so in 2 years.
Thanks for that RVermont, that’s what I was looking for.
Well, I guess you can teach an old dog new tricks. Woof!
I have never heard about a bi-directional RV relay. I think it is a great idea and would be good standard equipment. Now I will have to look into what makes these things tick.
__________________
Jim
Retired electronic technician (45 years in the field)
2017 Greyhawk 29W (solar & many other mods)
wife (maybe I should have given her top billing)
Well, I guess you can teach an old dog new tricks. Woof!
I have never heard about a bi-directional RV relay. I think it is a great idea and would be good standard equipment. Now I will have to look into what makes these things tick.
Ya, Jayco call it a “bi-directional relay” and some call it a B.I.M. “Battery Isolator Manager”
I wondering if anyone might know how low will the voltage in the chassis batteries need to drop to before the the battery isolator will switch over and start recharging the chassis batteries.
Not sure if I maybe have a problem?
When I started out a couple of weeks ago both sets of batteries were reading 13.2 volts. Monitoring them since the house batteries continue to be in the 13.2 range. But the chassis batteries have gone from 13.2 -12.8- 12.6 over the two weeks.
This is with the unit being plugged in continuously to shore power.
Thanks for that Jim,
It looks like as long as the voltage is above 13.1 in the coach batteries the chassis batteries should be getting charged. Hmmm?
In the trouble shooting section no mention on checking whether the chassis batteries are being charged.
I’ll have to go do some digging and find this relay and or solenoids and test voltage coming out.
Hopefully these come through. This is the unit I have in my 2018 37ts. The amperage might not be correct but the basis is the same..it says the unit needs to drop to 80% of charge before it starts charging again. The is a trouble shooting guide attached.
Thanks RVermont,
Mine is a 2018 ts as well, sounds like the first thing I need to do is have a look at which particular unit or set up my unit has. I’m assuming theses are located in the slide out battery compartment?
Correct. Just forward of the batteries. Good luck.
RVermont. Firstly, thanks you very much for all your help!
Looks like I have the same one as you, the discontinued one. When I can now I’ll go the procedures to check if it is operating properly. I’ll post what I find
Ok, just to update.
I have gone through and performed the Precision Circuits proper operation guide and it looks like everything is working properly. I did do it a couple of times and of coarse the voltages did change each time.
I have since talked directly with Precision and was told the chassis batteries must drop below 12.5 volts before the relay will switch over to charge the chassis batteries.
And of course I was being impatient monitoring the chassis batteries, it must be an age thing! Anyways it only went as low as 12.63 volts before I started wondering and checking if was working properly. And of coarse after doing all the testing with running the engine my chassis batteries are back up around 13 volts.
So I’ll continue to monitor and see where it goes
2017 Seneca. When storing we alway turn off that power sucking inverter, and also the disconnect switch. Careful with that switch, though, if you hold it down more than a second or so it will close that isolation solenoid, an both battery banks will discharge. The chassis batteries, being more willing to give up energy, will go first.
We have had our share of battery issues, and I perked up at the 80% charge statement. Makes me wonder at what point our Deltran tender kicks back in. If it waits until 80% charge, 3 or 4 amps might not be enough to completely charge all 4 house batteries before the little guy times out. That could be why the Deltran tech guy advised us to get the 5 amp model that does not have a timer.
That’s interesting I have just winterized my 2019 Senaca m2
I didn’t know they have built in smart charger so I can leave plugged in all winter and that won’t cook the batteries too much
Hmmm
The dealer have advised me to just start engine up and run it once an awhile
But now that it’s sitting around I realized the fridge was still coming on so unplugging it was the only way to shut it up
Remember that idling the engine won't warm up, and that can be bad if you do it enough. Take it out and drive it also for at least 20 minutes. This also keeps the tires from possible developing a flat spot.
Linear Mode
