Electric switch in "Storage" mode

[iainh1]

When the electricity switch is in storage mode, if my RV is plugged into shore power, will the battery still charge. I have a 2001 georgetown 350 RV... wondering whether to flip it to storage mode and leave it plugged in to the house 120v all winter and top up water when needed...

[polkatronron]

Leaving it plugged in all winter is not a good idea. If the batteries are fully charged, take off the negative cable in the battery and they will last all winter with no damage. I have done this for 30 years and live in an area where are winters are very severe...like -40 and have never had a batter freeze.

[Malco]

We take our battery out for the winter and store it on a shelf in our basement.In the spring we put it back in the trailer,charge it up and we're good to go.

[Herk7769]

Our camper came with a 3 stage converter in the Power Center. The Camper stays plugged in all winter. Once a month I peak into the filler caps to see it it needs water. Never had to add for a winter's worth of storage. I also have a shut off switch but only use it when I am fast charging off the dedicated battery charger and generator while dry camping.

[Malco]

Originally Posted by herk7769

Our camper came with a 3 stage converter in the Power Center. The Camper stays plugged in all winter. Once a month I peak into the filler caps to see it it needs water. Never had to add for a winter's worth of storage. I also have a shut off switch but only use it when I am fast charging off the dedicated battery charger and generator while dry camping.

Herk What's a three stage converter,how does it work,and what other advantages does it have over a basic converter,if any?

[jsutherl]

In my George town the batteries are not charged when then battery cutoff is set to off. However several things still draw power from the batteries with the switch set to off. Poor design in my opinion. Leading to dead batteries if you leave your coach sitting with the switch set to off. Even if it is plugged in.

I replaced my converter with a three stage (actually four stage) and I leave it plugged in all winter.

[jsutherl]

Originally Posted by Malco

Herk What's a three stage converter,how does it work,and what other advantages does it have over a basic converter,if any?

A three (or four) stage converter adjusts it's output voltage depending on what is going on.

The higher voltage you give a battery the faster it will charge. However giving a battery too high a voltage after it is charged will damage the battery and/or boil off the liquid inside.

A three stage converter gives a higher voltage (~14.4) until it detects that the battery is mostly charged.
Then it switches to a medium voltage (~13.6) until the battery is fully charged.
Then it switches to a maintenance voltage (~13.2) the will keep the battery charged but won't hurt it.

Sometimes converters have a fourth stage that boosts the voltage very high for a few minutes every week or two while in storage. This helps clean the plates in the batteries which should make then last longer.

So a three stage converter will charge your batters much faster and should not damage them if y leave it plugged into shore power for months at a time.

Most cheap converters are one stage and sit at 13.6 or 13.4 all the time.

If you've ever heard people say that starting the engine in your coach will charge your batteries faster that is because the alternator attached to the engine outs out 14.4v. So it will charge faster than a single stage converter.

There is a lot more to all this. We didn't even talk about amp ratings but those are the basics in what differentiates a three or four stage converter from a single stage.

[Herk7769]

Originally Posted by Malco

Herk What's a three stage converter,how does it work,and what other advantages does it have over a basic converter,if any?

I am sure your 2011 came with one also.

From the attached manual for my camper you can see that a newer converter and most good quality battery chargers "modulate" charging current based on battery voltage to avoid overcharging or "boiling the battery."

When you first charge a discharged battery, the voltage will be low and can accept a fairly stiff amount of amps under pressure (voltage) flowing into the battery.

uuummm, think of that battery as a very large "waffle" and each waffle "hole" will accept an electron. The charger has to be able to put an electron into each "hole." In the beginning this is easy since there are so many holes to choose from and no time is spent searching for an empty one. You can run the "electron hose" pretty much wide open without fear of "not finding a parking place" (charging current 25-35 amps - Stage 1 or BULK MODE).

As those holes fill (and the battery's charge and voltage increases) you can not keep that flow wide open. You have to dial back on the volume (amps) and decrease the pressure (voltage) to push those electrons around till they do find holes. If there are no holes to accept that charge readily available, heat builds up and the water in the battery will heat up and "boil."

So, the charger has to know the state of the charge and "step down" the charging current and decrease the voltage to maintain a safe charging level for the battery. Within a couple of hours of Full Out charging, the battery voltage and state of charge will trigger a decrease in amps and voltage (the next stage of charging also known as ABSORBTION MODE).

It will remain in ABSORBTION for several hours (up to 48) delivering about 4-6 amps (stage 2). If left there, like the older 2 stage converters, The battery will start to heat up as the capacity approaches 100% and boiling will start soon after. The newer converters have 3 stages and some new, higher end, ones (NOT OEM - LOL) have 4.

At about 90% of charge capacity, the converter will shift to stage 3 (or FLOAT MODE) and start trickle charging up to 100%. This current varies from about 1 amp initially down to 100 milliamps as the capacity goes from 90% to 100%. This process can take DAYS to fully charge a deep discharge battery, especially a high AH one (or bank).

the 4th stage of the higher end units have a "desulphation" stage which tracks charge/discharge cycles and "blasts" the "waffle" and knocks all the electrons loose and lets them resettle; basically re-newing the battery.

Folks who dry camp a lot quickly find out that there is not enough "not quiet time" at most campgrounds to full restore a heavily used battery (inverter running a Margarita Machine; TV surround system; half dozen computers; etc - JK) running the generator to charge the battery bank through the on board converter. So they use the generator to power a dedicated 2 stage battery charger connected directly to the battery - which is switched off while charging - and run the camper off the DC output of the power center. This DOES require monitoring as these chargers can overcharge the battery if you do not watch them; but since they do not go into "trickle charge" you can get 95% every day in the allocated run time..

[Herk7769]

Originally Posted by jsutherl

If you've ever heard people say that starting the engine in your coach will charge your batteries faster that is because the alternator attached to the engine outs out 14.4v. So it will charge faster than a single stage converter.

While it is true that an Alternator will put out 14.4 volts, the current available to charge the coach batteries is very low. The Alternator is designed to charge the starting battery, NOT the house battery. Starting batteries are designed very different from deep discharge batteries.

Using the "waffle" example earlier as a starting battery, picture a thin waffle with LOTS of holes. It lets out a LOT of electrons all at once, but then you are done. Almost no staying power. BIG cranking amps but limited longevity (Amp Hours).

Deep discharge batteries have a thicker waffle with deep holes that hold several electrons in each hole; BUT can only let one out at a time. Can't provide huge amounts of current, BUT can do smaller amounts for a LONG time (Big Amp Hours). (in fact the higher the current demand the lower the capacity. See the attached graph that plots Capacity verses Amp draw.