storage charging

[skychief12]

While storing my TT I would disconnect the battery using the switch, so no drainage.


Will the on-board converter still maintain a full charge if plugged into 120v?

[chuckster57]

If your plugged into shore power AND your disconnect is the proper position, yes your battery(s) will stay charged. If you do this, be sure to check the water level in the battery(s) at least once a month.

[skids]

You are probably aware, but do not operate things like slides, awnings, (and tongue jack?) while the battery is disconnected.

[mcomeaux]

I've got pig tails installed on batteries for Battery Tenders....
I've seen some plugged into shore power for extended periods
and boil batteries out....

[JRTJH]

I've got pig tails installed on batteries for Battery Tenders....
I've seen some plugged into shore power for extended periods
and boil batteries out....

If those trailers were equipped with WFCO converter/chargers, the power center was defective and needed to be replaced. The same thing can happen with a "Battery Tender" if it fails. The WFCO has a "Battery Tender" mode and as long as it's working properly, the charger will not "boil the battery". That said, any (and I believe all) batteries will, in low humidity/high temperature charging, evaporate a moderate amount of water from the electrolyte solution.

In short, if the WFCO is operating normally, it's doing exactly the same thing as a "Battery Tender"..... Any battery, regardless of the "source of charge maintenance" should have the electrolyte level checked frequently, otherwise a damaged battery is a potential issue.

[flybouy]

While storing my TT I would disconnect the battery using the switch, so no drainage.


Will the on-board converter still maintain a full charge if plugged into 120v?

As I read your question I understand it to ask if disconnecting the battery via a switch, will it still charge while plugged into shore power. The answer is no. That's like saying if I set a battery in the bed of my truck will it recharge while driving. NO connection, no charge.

So the bottom line is the battery must be connected to charge regardless of location (in storage, your driveway, or a campground, or driving). If I've misunderstood the question please let me know.

[travelin texans]

As I read your question I understand it to ask if disconnecting the battery via a switch, will it still charge while plugged into shore power. The answer is no. That's like saying if I set a battery in the bed of my truck will it recharge while driving. NO connection, no charge.

So the bottom line is the battery must be connected to charge regardless of location (in storage, your driveway, or a campground, or driving). If I've misunderstood the question please let me know.

And if equipped with some sort of battery disconnect it must set to the "connected" position otherwise no charging.
While in storage with batteries connected in place the best option is plugged into shore power & checking water levels at least monthly topping off with distilled water.
Next best if shore power unavailable is to disconnect the negative battery cable that goes directly to ground, this totally disconnects battery power. The factory installed disconnect, if equipped does not totally disconnect all parasitic drains.

[jasin1]

I know some people use solar chargers for batteries..don’t know how safe that is unattended though..an Amazon warehouse near me had 500k worth of fire damage today from a solar panel malfunction.

[Javi]

Should be required reading for new RV owners... :D

https://wfcoelectronics.com/wp-content/uploads/2016/03/WFCO-Theory-of-Operation-v2.pdf

[hxckidd]

I keep a trailer out on a property in the desert and use a small solar charger to keep the battery full while I am gone. 3 years without issue and works like a charm. always full when I get there.

[travelin texans]

I keep a trailer out on a property in the desert and use a small solar charger to keep the battery full while I am gone. 3 years without issue and works like a charm. always full when I get there.

While stored in Arizona I used a 3 amp solar charger with the + lead to battery #1 & the - lead to battery #2, the - cable disconnected that went to ground. This kept my batteries at 12.4 volts during storage & could operate the slides in/out once if needed, it would then recharge them back to 12.4 volts in a few days, checking water levels once a month.

[jasin1]

Yeah I guess the Amazon solar fire wasn’t relevant...it could have been something totally unrelated.

[skychief12]

Thanks for the responses. I spent a little time today with a multimeter. I was expecting the charger to be separate from draw down systems. NOT THAT WAY. I will be adding an external charger to use when stored.

[rhagfo]

I guess I just don’t get this keeping a charger or battery tender on an isolated battery.
Before we started full timing I installed a disconnect switch on on the battery positive lead, and on return from a trip I would switch it to off. I could go to the 5er a month later turn the switch to on and run our two slides out and back if I needed do some work. After another month still able run slides out and in.
This single Interstate SRM27 at seven years old would run our furnace in mid 30’s temps from 8:30 pm to 7:30 am with t-stat set at 65.

[BubbaShoots]

When I store my TT, I always disconnect my battery using the switch on the tongue. The battery won’t drain. You might consider a DuraVolt Marine Solar Panel Battery Charger from Amazon @$125. In effect, it is a battery tender without having to be connected to shore power. You can use a couple of suction cups to attach to your rv and run the wires to the battery. Very easy to install and use.

[hxckidd]

I guess I just don’t get this keeping a charger or battery tender on an isolated battery.
Before we started full timing I installed a disconnect switch on on the battery positive lead, and on return from a trip I would switch it to off. I could go to the 5er a month later turn the switch to on and run our two slides out and back if I needed do some work. After another month still able run slides out and in.
This single Interstate SRM27 at seven years old would run our furnace in mid 30’s temps from 8:30 pm to 7:30 am with t-stat set at 65.

When I store my TT, I always disconnect my battery using the switch on the tongue. The battery won’t drain. You might consider a DuraVolt Marine Solar Panel Battery Charger from Amazon @$125. In effect, it is a battery tender without having to be connected to shore power. You can use a couple of suction cups to attach to your rv and run the wires to the battery. Very easy to install and use.

This is exactly what I do, and the reason I do it is because my trailer is in the desert 100% of the time without power. So I use it for 3-4 days and let it charge while I am gone for a few weeks, come back out, and it's topped off for the next few days. I always shut off power to the batteries before I leave. This way I don't have to bring the battery home to charge ever, I don't have to run my generator unless I want AC. With it suctioned inside to a window, I do not have to worry about it being stolen, and it cost like $50.

[skychief12]

Sorry guys but batteries do lose voltage over time. The charger simply extend the life. You can prove that to yourself wit a multimeter (if you know how to use one).


This has been an eye opening experience.
I guess in my perfect world, I had expected advice to correctly determine the answer technically. I this case a refresher on multimeter test. Fortunately there is YouTube.

[flybouy]

Ok, I'm confused. In post 13 you "expected the converter to be seperate" from the load? Why? The converter supplies 12 v for the loads as well as the battery replenishment. I also do not understand why you would use a separate chargers if you have 120 v available. That's what the converter is for.

In post #17 you're complaining about not getting a "technical" answer to a completely ambiquis question? Good luck on Youtube......

[travelin texans]

While storing my TT I would disconnect the battery using the switch, so no drainage.

Will the on-board converter still maintain a full charge if plugged into 120v?

The factory installed switch DOES NOT totally disconnect the batteries so there WILL BE drainage, totally drained in as little as a week depending on what's bypassed that switch unless you disconnect the batteries.

If you have the above mentioned switch in the "disconnected" position then NO the converter WILL NOT charge the batteries, that switch must be in the "connected" position to charge them when connected to shore power, connected to truck or running a generator.


Honestly that's about as technical as those questions could be answered!