Battery Tender Question

[Docsouce]

2020 Jayco 26XD, single 12 volt house battery. After disconnecting the battery with the disconnect switch, and shore power off, (leaving the battery installed) can I use a battery tender to maintain the battery at full power. The reason I'm asking is that there still seems to be a slight drain on the battery even when it is disconnected with the switch and I don't know if the tender can keep up with it. I usually just leave the shore power on but I'm thinking of trying this method. Also I leave the battery installed so I can start the generator every 3 or 4 weeks. I guess I could just try it but hooking up shore power in January with a foot of snow on the ground would be a pain...

[jbrnigan]

I guess it depends on the much parasitic drain you have on your battery. I disconnect my shore power and use a tender from Nov thru Mar, and have never had a battery issue. I don't disconnect the battery from the RV, just hook up the tender. Also, don't forget to check your electrolyte levels if your battery has fill caps.

[Docsouce]

Thanks, that's just what I am going to do.

[RetiredOne]

Originally Posted by jbrnigan

I disconnect my shore power and use a tender from Nov thru Mar, and have never had a battery issue. I don't disconnect the battery from the RV, just hook up the tender. Also, don't forget to check your electrolyte levels if your battery has fill caps.

Exactly what I do too. I don't disconnect the batteries, in the rare case I have to move or use the rig. I just connect a battery tender to both house and chassis batteries, and they stay perfectly charged all Winter.

I actually use a digital timer, and only have them come on twice a week. There's not enough parasitic drain that it's required to keep them on 24/7.

[cherv]

If you have shore power for battery tender, why not just plug rv into shore power, both rv and chassis batteries will stay charged. Our class c is in our driveway plugged in all yr.

[RetiredOne]

Originally Posted by cherv

If you have shore power for battery tender, why not just plug rv into shore power, both rv and chassis batteries will stay charged. Our class c is in our driveway plugged in all yr.

I personally don't like having the 120 volt system energized 24/7 needlessly, if plugged into shore power all Winter. I don't leave it plugged in during the Summer either. I just plug it in when the batteries need a topping or if we're leaving on a trip, and I want to pre-cool the fridge.

Plus, like I said, even on a battery tender, the batteries don't lose enough juice during the week to require them to be on 24/7.

[gprapim]

Originally Posted by cherv

If you have shore power for battery tender, why not just plug rv into shore power, both rv and chassis batteries will stay charged. Our class c is in our driveway plugged in all yr.

Be careful, because unless you have installed something to keep your chassis battery charged, simply plugging your coach to shore power will only charge your house battery(s). You would need an additional charger to charge your chassis battery.

[RogerR]

I installed a battery shutoff on the negative battery post itself. This prevents the parasitic drain from the CO/LP detector and maybe a forgotten light. 7$ on Amazon. I also use a Battery Tender Junior. It will very slowly bring up my battery if I leave it connected and it is part down before I attach it. I try to use the house system to fully charge it before I use the battery tender. When I store for the winter my LP is off and so is the main power, no one is in it so I don't worry about CO or LP leaks during the winter.

[cherv]

our 2019 jayco class c 22j charges both coach and chassis battery. check it out on your unit...I called jayco to confirm.

[gprapim]

Originally Posted by cherv

our 2019 jayco class c 22j charges both coach and chassis battery. check it out on your unit...I called jayco to confirm.

That’s good they must have changed that on yours, because I have a 2017 and it doesn’t work that way .... and most coaches do not either. If you want to be sure, put a volt meter on the chassis battery before you plug the coach in and then do do after you do so. If the voltage increases from the 12’s to higher, then that is the case. If it does not, then you need to change course and add a battery charger to charge the chassis battery. Check it out and see for yourself. It wouldn’t be the first time that Jayco gave out the wrong info. Just sayin” !!

[cherv]

Hi, do you have an auxillary start switch on the dash to left of steering wheel? If so both batteries are connected and charged from either engine or shore power.

[gprapim]

Originally Posted by cherv

Hi, do you have an auxillary start switch on the dash to left of steering wheel? If so both batteries are connected and charged from either engine or shore power.

Yes I do, and no, they are not. My chassis battery does not charge when plugged into shore power, and most coaches do not, either. I strongly suggest you check yours out before you find out the hard way. You can jump the two terminals on the aux start and that, in fact will charge the chassis battery when plugged in, but it will not happen otherwise. Like I stated earlier, check yours out with a volt meter. It is very easy to do and it will prove it to you one way or the other.

[RetiredOne]

Originally Posted by gprapim

Yes I do, and no, they are not. My chassis battery does not charge when plugged into shore power, and most coaches do not, either. I strongly suggest you check yours out before you find out the hard way. You can jump the two terminals on the aux start and that, in fact will charge the chassis battery when plugged in, but it will not happen otherwise. Like I stated earlier, check yours out with a volt meter. It is very easy to do and it will prove it to you one way or the other.

Just coming to post that. Cherv needs to put a digital meter on his chassis battery, then plug in shore power, and see if the voltage jumps up from it being charged from the converter. My guess, it doesn't. I have a 2019, and my rig doesn't do that.

[cherv]

We have a 2019 jayco class c 22j. Just received an answer from jayco motorized services regarding shore power and charging both coach and chassis batteries. The converter sends charge to both batteries when on shore power, no need to use battery tender for my unit based on #vin.

[cherv]

Just received answer to my question from jayco motorized services and yes for my 2019 22j (vin#) charges both batteries on shore power.

[gprapim]

Originally Posted by cherv

We have a 2019 jayco class c 22j. Just received an answer from jayco motorized services regarding shore power and charging both coach and chassis batteries. The converter sends charge to both batteries when on shore power, no need to use battery tender for my unit based on #vin.

It may be true, but do yourself a favor and put a volt meter on it anyway .... just to be certain.

[cherv]

will to satisfy both our comments. will disconnect shore power then meter both batteries. reconnect shore power and again meter both batteries

[gprapim]

Originally Posted by cherv

will to satisfy both our comments. will disconnect shore power then meter both batteries. reconnect shore power and again meter both batteries

That will work. The only one you need check is the chassis battery; we know the coach battery will charge when on shore power. Let us All know what you find out.

[cherv]

no difference with shore power connected of not connected. coach batt. 13.23, chassis batt. 12.27. last yr only shore connected NO btt. tender to chassis batt. Spring coach started up, no problem

[gprapim]

Originally Posted by cherv

no difference with shore power connected of not connected. coach batt. 13.23, chassis batt. 12.27. last yr only shore connected NO btt. tender to chassis batt. Spring coach started up, no problem

Cherv, If your chassis battery is being charged by shore power, and your coach battery is at 13.23V, your chassis battery should read the same. Your chassis battery is reading only 12.27V, which is in a state of discharge. It is only at a 55% of a full charge. Therefore, you are not charging your chassis battery when you are plugged in. I suggest you get yourself an automatic battery charger with a 2 to 4 amp capacity to keep on your chassis battery when you plug in for any extended time. I am attaching a 12V battery charge chart to show you where yours is sitting right now. Hopefully, this will convince you of what is actually happening when you are plugged in
. I hope this helps.