Trickle charge vs battery disconnect

[perrien]

Our storage place has a 120v outlet for charging the battery. If the battery disconnect is off (red handle pulled out), will the battery charge or does it need to be on?

I have a 2970RL if it matters.

[Cate&Rob]

perrien - The battery switch has to be on to connect the on-board shorepower converter (battery charger) to the battery. On the other hand, if you pull the negative cable off the battery (to assure a complete battery disconnect) you can store the RV for many months without discharging the battery. A lead acid battery “self discharges” at less than 5% per month. So, for example, after 3 months of storage the battery will still be above 85% state of charge.

Rob

[perrien]

Thanks for the info. I'll be doing a little monitoring of the battery and charge over the coming weeks and see how exactly I want to store it.

[boyscout]

perrien - The battery switch has to be on to connect the on-board shorepower converter (battery charger) to the battery. On the other hand, if you pull the negative cable off the battery (to assure a complete battery disconnect) you can store the RV for many months without discharging the battery. A lead acid battery “self discharges” at less than 5% per month. So, for example, after 3 months of storage the battery will still be above 85% state of charge. Rob

Rob what is it that uses battery power when the red disconnect key is removed? I'm guessing that the CO2/propane alarm probably does (to avoid lawsuits) but wonder what other reasons explain the fact that the disconnect switch doesn't completely disconnect the battery.

[Cate&Rob]

Rob what is it that uses battery power when the red disconnect key is removed? I'm guessing that the CO2/propane alarm probably does (to avoid lawsuits) but wonder what other reasons explain the fact that the disconnect switch doesn't completely disconnect the battery.

Over the years, it seems that GDRV products have been wired different ways. Some with several circuits bypassing the OE battery switch and some with very few. The parasitic loads that come to mind are the CO detector and memory functions in the sound system. These don't seem like much, but several on this forum have reported a single 12 battery going dead in a week or two if the battery is not completely disconnected. Removing a battery cable will do this . . . or installing a true 100% battery disconnect switch that completely isolates battery.

Rob

[klenger]

You could use the external solar charge port connected to a stand-alone trickle charger to keep the battery charged. As long as the solar port wiring is tied directly to the battery (via a fuse), you could leave the battery disconnect switch off.

Something like this

[Hokensalem]

When I stop using my 2970 for the year I remove the battery and store inside my garage. I use a trickle charger to keep it up. Will last a lot longer than keeping it outside.

[alanhenson]

The only problem with unhooking the battery is the factory charger can't charge batteries to 100%. So you likely start or at 75% or less in reality then 5%/month. I was shocked when I hooked up a smart charger with solar panel to what I thought were full batteries. Not even close. They were near 50% and that's after being on 50amp shore power for 4 days straight. After I solar charged then everything in the coach worked better. I'm changing out the charger/inverter soon. Piece of junk. Not even as smart as a &40 charger from Wal Mart.

Sent from my SM-G955U using Tapatalk

[Jerryr]

The only problem with unhooking the battery is the factory charger can't charge batteries to 100%. So you likely start or at 75% or less in reality then 5%/month. I was shocked when I hooked up a smart charger with solar panel to what I thought were full batteries. Not even close. They were near 50% and that's after being on 50amp shore power for 4 days straight. After I solar charged then everything in the coach worked better. I'm changing out the charger/inverter soon. Piece of junk. Not even as smart as a &40 charger from Wal Mart.

Sent from my SM-G955U using Tapatalk

Hum, on our 2017 337RLS the factory onboard charger works pretty well. With a discharged battery it will work the charge voltage up to 14.4 volts bulk charge mode then drops into float mode of 13.2 volts or 13.6 volts in normal mode.

I monitor the voltage on our Ground Control 3 display.

BTW, with the battery disconnect switch set to disconnect the GC3 still has power.

[Jerryr]

Let me post the section of a typical WFCO charger converter relating to operation mode.

If your voltage ever drops below 13.2 while on shore power there’s something wrong.