Battery disconnect - can I still use my heat?

[ScottyP5947]

Hello fellow RV friends!
I have a travel trailer and was wondering if I can disconnect my batteries for the winter so that they last longer but still have it plugged into shore power so I can use the heater? Should I turn the converter off too?
Thanks everyone!
Scott

[6_2Superduty]

Somewhat related, my owners manual says not to operate slide without a battery.

[ScottyP5947]

Thanks 6.2! Seems a high draw could totally cause an issue.
I got my converter today and BONUS! I got a 4 stage 75 amp power max instead of what I ordered (3 stage 55 amp) 😄
I'll take the upgrade.
I will eventually install larger gauge charging wires, once I pull the ramset fasteners off the belly. Haven't figured out an easy way to get them out. I'll just replace with self taping screws once I decide to tackle that project.
I'll keep you all posted.
Thanks Scott

[6_2Superduty]

Somewhat related, my owners manual says not to operate slide without a battery.

[ScottyP5947]

Sounds good. Thanks again for the info!
My new converter shows up tomorrow. 🙂

Scott

[wnjj]

ADK Camper wrote:
So using an automotive charger to charge the two batteries at the same time is no issue? Connected to positive on one battery and negative on the other, of course.

Not quite. If you are using two 12 volt batteries you can connect one to the camper and the other to the charger alternating as required. If you choose to use two 12 volt batteries at the same time they must be connected in parallel. That is connect positive to positive and negative to negative on the batteries and either positive to camper positive and either negative to camper negative. With the batteries connected as above you can connect a stand alone charger by connecting its positive to either battery positive and its negative to either battery negative.

For balanced charging of paralleled batteries you want to connect the positive and negative charger leads to opposite batteries and not both on the same battery. I think that’s what the poster above was suggesting.

[ADK_Camper]

So using an automotive charger to charge the two batteries at the same time is no issue? Connected to positive on one battery and negative on the other, of course.

Not quite. If you are using two 12 volt batteries you can connect one to the camper and the other to the charger alternating as required. If you choose to use two 12 volt batteries at the same time they must be connected in parallel. That is connect positive to positive and negative to negative on the batteries and either positive to camper positive and either negative to camper negative. With the batteries connected as above you can connect a stand alone charger by connecting its positive to either battery positive and its negative to either battery negative.

[ScottyP5947]

I've learned a lot here, I appreciate it!
I'll do that going forward. I have a decent automotive charger and will use it in parallel with my on board charger when I need to charge quickly when boondocking.

I'm still upgrading my onboard converter/charger to the Power max.

So using an automotive charger to charge the two batteries at the same time is no issue? Connected to positive on one battery and negative on the other, of course.

I'm doing this until these two 12v batts go bad - then I'm going to a 6V golf cart batt bank.

Thank you!
Scott

[ADK_Camper]

SoundGuy wrote:

ScottyP5947 wrote:
For that reason alone, it seems I should replace the converter. Agreed?

Simply replacing the converter won't change the fact you're charging through cables that are far too long and of insufficient gauge. I simply turned my WFCO off and used a stand alone charger but there's no reason you couldn't do the same with a stand alone charger.

Sound guy is right. An inexpensive manual charger is a good fix for this problem. I have a standard ac outlet in my front storage compartment which enables me to store the charger there and connect it to the battery as needed. With a 10 amp charger I can run my generator about 1 to 1 1/2 hours every other day to keep my battery sufficiently charged. I don't shut off/disconnect the WFCO converter when using the standalone manual charger. The two just run in parallel. This ensures that 12 volt power is never interrupted so on board electronics maintain their settings.

[ScottyP5947]

Yeah I do understand that part of it too, sound guy. Woefully inadequate overall, really. I'm amazed at how inexpensively these things are built.
Are you recommending using a normal automotive battery charger when boondocking, for a faster charge?
I haven't torn into the underbelly of my coach just yet and I would actually consider increasing the gauge of my cables while I'm in there but it's not a huge priority just yet.

I did buy an upgrade - a Powermax multi stage converter - that'll move me in the right direction. I plan to have this coach for a while so I want to make things better where I can.

Thanks Scott

[SoundGuy]

ScottyP5947 wrote:
For that reason alone, it seems I should replace the converter. Agreed?

Simply replacing the converter won't change the fact you're charging through cables that are far too long and of insufficient gauge. I simply turned my WFCO off and used a stand alone charger but there's no reason you couldn't do the same with a stand alone charger.

[ScottyP5947]

Great info! I found the manual and it didn't have a ton of info but was useful nonetheless.

I did an experiment, I ran my batteries down to about 12.1 V, then plugged it in. The voltage it was charging at was 13.36 volts. That tells me that mine doesn't push 14.4, ever. That probably explains why my rig doesn't charge quickly when connected to my generator. For that reason alone, it seems I should replace the converter. Agreed?
Thanks for the info!

Scott

[ADK_Camper]

ScottyP5947 wrote:
Good info ADK camper, thanks! Is there any way to see what mode the converter is operating at? My batteries never read higher than 13.1 V, as read by my solar panel controller.
I'll have to pay closer attention when I deplete my batteriesbatteries.
Thanks
Scott

Boost mode is 14.4 V, absorption mode is 13.6 V, and float mode is 13.2 V. A digital voltmeter connected directly to the battery terminals will give you the best way to determine what voltage is actually charging the battery. (You can often get a free digital meter at Harbor Freight with any purchase and a coupon from the Sunday paper) If your camper came with manuals from the appliance manufacturers, it will give you more details about the converter's operation. You can also probably find the manual on line.

[ScottyP5947]

Good info ADK camper, thanks! Is there any way to see what mode the converter is operating at? My batteries never read higher than 13.1 V, as read by my solar panel controller.
I'll have to pay closer attention when I deplete my batteriesbatteries.
Thanks
Scott

[ADK_Camper]

ScottyP5947 wrote:
Yup looks like I have a WF-8900 converter. They spec out to be a decent model that won't overcharge the battery according to the brochure.

Thanks
Scott

I too have a WFCO converter. It is designed to operate in one of three modes: boost, adsorption, or float depending on the automatically sensed charge state of the battery. BUT WFCO chargers are notorious for not operating properly. Mine always operates in adsorption mode regardless of the batterys state of charge. Because of this it takes a long time (days) to bring a 50% discharged battery up to a full charge and it tends to overcharge a full battery. If your charger operates in the same way it might be better to allow the converter to fully charge your battery and then disconnect it for a few weeks (assuming it's not being used) and then bring it up to a full charge and repeat the cycle every few weeks.