Battery over charge?

PieGuy · 05-02-2016, 11:13 AM

Can the battery overcharge if the trailer is left plugged in at home? I've been working in the trailer so I am leaving it plugged in. I know it will charge the battery but is the charge circuit smart enough to turn off when the battery is fully charged?

profdant139 · 05-02-2016, 11:44 AM

Yes -- the converter in your trailer should be able to avoid an overcharge. But there is a slightly better solution, if you are interested in preserving the useful life of your battery -- get a Battery Minder Plus, or an equivalent device. You hook it up to the battery and it delivers a trickle charge. More importantly, it pulses so as to avoid "sulphation" of the plates -- if you are interested in the technical details, this can be easily Googled.

Don't just unplug your battery and let it sit there -- it will discharge and it will deteriorate. Please do not ask how I learned this expensive lesson.

There are lots more tricks and tips for proper battery maintenance, most of which I ignore -- too much effort. For sure, check the water once a month and fill as needed with distilled water only. Maybe get a specific gravity hydrometer (very cheap device) so you can tell when a cell is about to go bad -- that thing saved my bacon once, before a big trip -- I replaced the batteries just in time.

Eagle · 05-02-2016, 01:38 PM

I'll never use a battery where one has to check the water level anymore.

When the original battery fails, it gets replaced with a "gel cell" sealed battery like the Optima series.

In the camper, I use one like this: Optima Batteries 8016-103 D34M BlueTop Starting and Deep Cycle Marine Battery that is sold by Amazon.

Some Optima batteries I've had in vehicles for 10 years ..... never had one fail yet.

gmw photographics · 05-02-2016, 04:40 PM

Quote:

Originally Posted by PieGuy

Can the battery overcharge if the trailer is left plugged in at home? I've been working in the trailer so I am leaving it plugged in. I know it will charge the battery but is the charge circuit smart enough to turn off when the battery is fully charged?

It will mostly depend on what kind of "converter/charger" your trailer has. If is just a single stage charger, then yes it will likely overcharge the battery. But if it's like most later model trailers, it will have a three or even possibly a four stage charger.

My 2012 FF came with a 3 stage charger. When the battery is fully charged, the charger drops to a "maintain" voltage of right at 13 volts, with very low amperage output. This will keep the battery charged, and will not result in an overcharge.
This trailer has the original "marine, starting/deep cycle" AGM battery that is now coming up on five years old. I leave it plugged in to shore power all the time at home, and I do almost all of my camping where I have electrical hookup. In other words, it's plugged in all the time basically.

Check to see what your converter/charger is. Come back and tell us what the make and model of it is, and perhaps we can be more specific to your particular trailer situation.

PieGuy · 05-02-2016, 06:24 PM

It's a Centurian cs3000.

gmw photographics · 05-02-2016, 08:21 PM

Pie,
I did a little searching the web and really could not come up with any specs for that converter. It's likely the original that came in the trailer, and has been discontinued. Which leads me to think it may be pretty old technology....in other words, it may not be multi stage.

One way you can test to find out would be to plug the trailer into shore power, and take a reading at the battery to see what the voltage is. If the charger is for instance, putting out let's say 13.6-14.2 volts, then that would likely be fairly normal. Now then, go back the next day, or several days later ( with it left plugged in to shore power the entire time ), and read the voltage again. If you are still seeing 13.6 to 14.2 or so, then there is a pretty good chance it's just a single stage charger ( this is assuming the battery is good, and has taken a charge correctly ).

But if you are now seeing around 13.2 or so, then it is likely a multi-stage, and has gone into a "float" mode. If you are seeing this 13.0 to 13.2 or so, then you are good and are in a nice comfortable maintenance mode.

There may be a label on the converter that shows what it's specs are.

You may want to consider replacing the converter with a new, modern one. Progressive Dynamics comes up often as a good brand.

Many modern travel trailers come with a china made WFCO converter/charger. Lots of folks talk trash about them, but truthfully, there are probably hundreds of thousands of them in service that are working fine. So you can decide for yourself whether all the trash talk about that brand is valid or not. So far, my WFCO is working fine, going on 5 years.
But if I were going to replace it, I would buy a PD, if for no other reason than it's made in USA, and it has a good reputation.

....hope this helps.

GrandpaX10 · 05-02-2016, 08:29 PM

For more battery charging information, I recommend: The 12volt Side of Life (Part 1).

Good reading.
Dale

Ed Venture · 05-02-2016, 08:30 PM

Pie,

As mentioned, with the factory unit you will significantly shorten the life of your battery if you leave it plugged in all the time. What happens is that you end up boiling off your battery electrolyte and you expose your plates. You can keep your batteries topped off with distilled water, but even at that you will be fighting an uphill battle.

I installed this PD9100 Series RV Power Converter from Progressive with the charge wizard pendant when I converted from my single 12V to my dual 6V battery unit. It is much easier on the batteries as it will settle down to 13.4V to maintain and then kick up to 14.4V for 20 minutes every 24 hours to desulfinate the plates.

I think I paid around $100 for it and modified the existing power center to make it fit. It was a pretty easy project and only took an hour to covert.

Ed