To Trickle Charge, or Leave on Shore Power

[deluco]

I purchased a new Class A coach and am being told different things about how/if to charge while stored. I am curious if I should use a "smart" trickle charger or if I have the option, would it be better to leave plugged in to shore power while stored? I have a 50amp cord coming from the coach, 50-30 amp adapter and also a 30-15 amp adapter. What's the best way to keep the coach batteries fresh while being stored? Thank's

[wolfe10]

I purchased a new Class A coach and am being told different things about how/if to charge while stored. I am curious if I should use a "smart" trickle charger or if I have the option, would it be better to leave plugged in to shore power while stored? I have a 50amp cord coming from the coach, 50-30 amp adapter and also a 30-15 amp adapter. What's the best way to keep the coach batteries fresh while being stored? Thank's

The reason for different answers is, that indeed it DEPENDS. If you have a "smart" converter, charger or inverter/charger AND it is properly programmed, leave it plugged in 24/7.

If you have a "dumb" converter you do not want to keep it plugged in 24/7 as it is likely to overcharge the batteries and boil out the water.

Smart units (when properly programmed) maintain battery voltage at the proper 13.2-13.5 VDC. So, at least 24 hours after plugging in (to allow the unit to cycle through the bulk and absorption phases and reach FLOAT) measure voltage at the batteries with a digital voltmeter.

This will also tell you that BOTH battery banks are being charged as is best if stored long-term.

Read your charger's owners manual for programming instructions. The "smarter ones" ask for several things: battery size (in amp-hrs), type of battery (wet cell, gel or AGM), ambient temperature (for those that do not have a temp probe on the battery), etc..

[deluco]

Thank you

[-Gramps-]

Not all coaches are set up to charge the chassis battery when on shore power. My coach will not. I added a device myself that remedies this. It is called a Trik-L-Start. It runs off 12 volts and "borrows" voltage from the house batteries to keep the chassis fully charged. It also has a maintenance mode that helps to keep the battery healthy. It is very easy to install and cost about 56 bucks at Rvupgrades.

[Guest 2driftrs]

The real issue here goes beyond battery charging. The worst thing to do to a motorhome is let it sit idle for weeks at a time, plugged in or not. I could (should?) write a book on what happens to idle motorhome engines, transmissions, wheel bearings, appliances, etc. when they sit idle, but for now, my words of advice are, if you can leave it plugged in, do so. If you can move it at least once a week, do so. If you're plugged in, let the appliances run.

Summer or winter, our rig is on shore power if we're not on the road. It gets started and moved at least every week. The heat pumps are on, the fridge is on and the water pump gets exercised to purge all the lines. I don't have a smart charger, and it only charges the coach batteries. The engine battery is charged off two 15 watt solar panels. I check battery acid levels every couple of months.

We replaced the coach and engine batteries 2 years ago, so 8 years out of the original 6 year batteries ain't so bad.

[wolfe10]

The real issue here goes beyond battery charging. The worst thing to do to a motorhome is let it sit idle for weeks at a time, plugged in or not. I could (should?) write a book on what happens to idle motorhome engines, transmissions, wheel bearings, appliances, etc. when they sit idle, but for now, my words of advice are, if you can leave it plugged in, do so. If you can move it at least once a week, do so. If you're plugged in, let the appliances run.

Summer or winter, our rig is on shore power if we're not on the road. It gets started and moved at least every week. The heat pumps are on, the fridge is on and the water pump gets exercised to purge all the lines. I don't have a smart charger, and it only charges the coach batteries. The engine battery is charged off two 15 watt solar panels. I check battery acid levels every couple of months.

We replaced the coach and engine batteries 2 years ago, so 8 years out of the original 6 year batteries ain't so bad.

Agreed-- it is better to use them than just let them sit.

But, let's define "drive it" (while being stored). If you can't drive it at least 25 HIGHWAY miles, don't start it. To be effective, you need to get the oil, not just coolant up to operating temperature.

And for those with a "dumb" converter that could overcharge the batteries of left on 24/7, an option is to buy a HD timer, like at Home Depot) and plug the converter into it. Let it come on for an hour a day.

Brett

[Guest 2driftrs]

Brett is right in that a 25 mile drive is best, but I think if you can't do that, at least run the engine long enough to get it to operating temperature and circulate fluids. Sometimes I'm just plumb too lazy to go for a drive (and too cheap to waste ten bucks on gas) so I cruise in the driveway to get everything moving - - engine, tranny, drive shaft, rear axle, wheel bearings, etc.

In the world of automotive engineering, there are at least a million articles about the storage of vehicles. I'm not smart enough to decide which ones are right or wrong, so I tried to apply some common sense to the subject.

For an example, a motorhome that sits idle will develop rust on the brake rotors overnight. The longer they sit, the worse it gets. Let it sit long enough, say a few weeks, and then drive off. The rust does a job on your brake pads! It doesn't destroy them, just takes a few extra miles from their life expectancy. Doesn't help the rotors much, either. Driving a few feet back and forth will polish the rotors and prevent pitting.

Unless you've got a climate controlled storage area, condensation is a motorhome killer! Water vapor (humidity) will condense on everything from your brake rotors to your exhaust system. Running the engine once a week and driving a few feet will at least circulate fluids to surfaces that may have "dripped dry" like engine bearings, transmission parts, etc.

[wolfe10]

Brett is right in that a 25 mile drive is best, but I think if you can't do that, at least run the engine long enough to get it to operating temperature and circulate fluids. Sometimes I'm just plumb too lazy to go for a drive (and too cheap to waste ten bucks on gas) so I cruise in the driveway to get everything moving - - engine, tranny, drive shaft, rear axle, wheel bearings, etc.

Actually, at least, the major diesel engine manufacturers all suggest NOT starting their engines unless they can be driven at highway speeds long enough to get the oil up to operating temperature. Starting and idling, even at high idle, is worse on the engine than not starting it at all.

Brett

[Guest Wayne77590]

Brett,

I have to ask.

When I'm getting ready to pull up stakes, I start the engine to pull in the slides and raise the jacks. Then I go outside and unplug the power cord. So it could be sitting there building up air pressure and idling for about 5 minutes before we "get underway." So now the question. Is that satisfactory to do?

p.s., The manual states to run the engine to operate the slides. That allows the alternator to provide some of th 12 vdc instead of drawing just off the batteries.

[wolfe10]

Brett,

I have to ask.

When I'm getting ready to pull up stakes, I start the engine to pull in the slides and raise the jacks. Then I go outside and unplug the power cord. So it could be sitting there building up air pressure and idling for about 5 minutes before we "get underway." So now the question. Is that satisfactory to do?

p.s., The manual states to run the engine to operate the slides. That allows the alternator to provide some of the 12 vdc instead of drawing just off the batteries.

Wayne,

If the owners manual calls for the engine to be running, then I would do it that way. But, it would surprise me that this would be necessary to provide extra 12 VDC amps IF you are still plugged in-- your converter/charger, particularly after being plugged in overnight will have the batteries plenty charged to bring in the slides. Perhaps there is some other reason???

And most recommend starting the diesel, letting the engine idle for 30-40 seconds and then bumping the idle up to high idle speed (1,000 to 1,100 RPM) for faster warm-up. Most coaches have this idle up feature in the cruise control.

Brett

[cebuffett]

Wayne,

If the owners manual calls for the engine to be running, then I would do it that way. But, it would surprise me that this would be necessary to provide extra 12 VDC amps IF you are still plugged in-- your converter/charger, particularly after being plugged in overnight will have the batteries plenty charged to bring in the slides. Perhaps there is some other reason???

And most recommend starting the diesel, letting the engine idle for 30-40 seconds and then bumping the idle up to high idle speed (1,000 to 1,100 RPM) for faster warm-up. Most coaches have this idle up feature in the cruise control.

Brett

When getting ready to leave camp, my coach's instructions call for the engine to be started and the jacks retracted before pulling in the slides. This brings the air springs to normal height and no chance for the jacks to be putting any force on the frame. This way the slides should always pull in straight.

Cliff