Trickle charger vs. stock converter on a timer

[doughpat]

Hi all, I did a search for this and did not see anybody compare and contrast the advantages and disadvantages of both: using a trickle charger constantly hooked up to the battery terminals, versus plugging into shore power via a timer programmed to allow power to flow just one hour a day.

Note: these scenarios both involve leaving the battery disconnect switch in the “on” position (I. E. The battery is providing power to the “background” systems in the airstream)

If it makes any difference: I have a stock 12 V continental lead acid RV/marine battery. It is supposedly in good shape, according to AutoZone who performed a load test on it.
Also, this is a 2019 Bambi sport, with no modifications to the electrical system.

[alano]

I think you have a 3-stage converter which means it's fine to keep your converter running 24/7 while connected to shore power. So the answer is number 3!

[doughpat]

Any way to verify that I have a decent three way converter that I can (safely) leave plugged into shore power all the time?

I keep reading about people’s stock converter “boiling” (or otherwise damaging) their batteries.

(I hope that doesn’t apply....it would be very disappointing that a 2019 AS would come equipped so poorly!)

[steverino]

I usually just plug into shore power thru a timer, and set the timer to run for a few hours once or twice a week. One disadvantage to this is that when it turns on, it will pull a lot more current than a trickle charger does, at least for a while. It is a factor if, for instance, you are in a storage unit and sharing a supply circuit with several other units.

And in certain circumstances, can even blow the supply breaker. I experienced this just last week - I had arrived home from Las Vegas, where we were running the air conditioner. Thermostat was set low, and once I plugged in at the storage unit, the a/c fired up, quickly blowing the breaker. Lesson learned, I need to make sure the A/C is off before plugging into storage.

An advantage of using house power (not trickle) is that it is easy to bypass the timer if you need to chill down the refrigerator in preparation of leaving on a trip. Just mind the total load on the supply circuit!

[doughpat]

That is a very good point. fortunately I will have the option of doing either one. I have it under a carport at my home with power to it.

So am I correct in assuming that it would damage my battery to leave things plugged into shore power all the time?

The trickle charger brought my battery from 12.6 V up to 12.8 V in about three hours. Nice and slow.

[Daquenzer]

I use a trickle charger on the batteries. In fact I leave a trickle charger on all the time I am not using the unit. I did it the other way one year, and it was fine. I hear lots of conflicting statements. So those that are camping all the time are constantly plugged into the shore power at 50 AMPS. You would think it would fry their batteries. Yet it doesn’t. So it’s hard to sift through all the noise.

The one thing I do know: the trickle charger works fine. I check the water levels and they are fine. My batteries work and stay fully charged. I’m good.

[doughpat]

Originally Posted by Daquenzer

I use a trickle charger on the batteries. In fact I leave a trickle charger on all the time I am not using the unit. I did it the other way one year, and it was fine. I hear lots of conflicting statements. So those that are camping all the time are constantly plugged into the shore power at 50 AMPS. You would think it would fry their batteries. Yet it doesn’t. So it’s hard to sift through all the noise. .

I wonder if the reason people who are constantly plugged (while camping) don’t have any problems is because they are generally using power. Perhaps that prevents overcharging?

Maybe it is the extended periods of no significant power use while being plugged into shore power that does the harm to the batteries?

[Wayne&Sam]

I use a trickle charger connected all the time. Last set of stock batteries lasted seven years, this set in on year six. So it works for me.

[Bill M.]

One way to verify what the converter is doing is to look at the battery voltage while plugged in. It should drop down to a float voltage when the battery is charged and there is no load. In other words, it should do about the same thing as the trickle charger.

I have a replacement converter in my older trailer and I just leave it plugged in. I used to use a timer. I have pulled the battery and used a trickle charger. I hate messing with batteries. I would put it on a timer if I was worried about it instead of disconnecting and using the trickle charger.

Whatever you do the battery is not going to last forever if you use it while camping. One to 2 years for lead acid for me. I use a CPAP and we use lights, WP, and fan when camping without hookups. We have 2 batteries. I get down around the 50% discharge limit in 2 days when first out and in one day thereafter.

I think either way you decide to do it will be fine.

[AzAirstream]

I use a trickle charger with the power switch in the cabin "off" with good results. Just keep the batteries full of water.

[Lensman]

Our Safari is in storage most of the year and I have found a 12volt solar charger at Harbor Freight which I leave plugged in all the time. It has kept the battery charged for 3 years now. It was only around $15.

[cazual6]

I do both, here is my setup:

On Thursday (I just picked a date, I figured, Thursday since I will likely go on a weekend)


Thursday 6a
Batter Tender OFF
Shore Power ON
-I have a Dehumidifier that will be recharged by outlets being ON
Thursday 2p
Shore Power OFF
Batter Tender ON


Battery Tender is connected directly to the battery.

[waninae39]

get a smart charger. they know when , how much and how long

a simple dumb charger could easily shorten the life of the battery

IMHO, using a timer is penny wise, dollar foolish

[doughpat]

I understand your point, Waninae. Out of curiosity, do you have one you’d recommend? These forums are full of threads on this subject, makes my head spin.

[majorairhead]

We have a '19 International. I back it in to our garage, plug in to the 50 amp we are so fortunate to have, and forget about it.

I've been doing it this way for a little over a year with no issues.