Community Forums

captaindesmo · 11-20-2011, 11:00 AM

If I put a charger on my main battery will it also charge coach batteries? Does the battery switch (inside coach) disconnect the 12v from 6v batteries. In rv storage, how do people keep batteries from going dead over and over. I cant keep a charger or battery tender on it full time but I can gharge it overnight once a week, but will that charge 6v batteries? will that eventually kill battery? Is there a solar battery charger that I can put on roof and connect while parked? Any battery Maint. tips/advice will be greatly appreciated. Most units in my rv storage just seem to sit for weeks at a time. How often should a good battery need charged? I have let my van sit for a month and start right up

Georgia · 11-20-2011, 11:20 AM

my coach was designed from the factory to charge the chassie batteries from the engine alternator, and the house batteries from the generator/shore power. There is no interconnect between them. I was going to install a marine grade A/B/BOTH switch to be able to cross connect the batteries with the flip of a switch, but I ended up just getting a trickle charger for the chassie batteries that is connected to the generator/show power system. Works great.

cheers
geo

ps: all the batteries are 12V on my rig. 4 on the house side and 2 on the chassie side.

LVJ58 · 11-20-2011, 11:38 AM

Much depends on whether you have 2 battery disconnect switches in your coach, one for chassis battery and one for coach(house) batteries and how your battery isolator functions.

Our coach is equipped with an Intellitec "Battery Control Center" where our isolator relay and both chassis & house battery disconnect relays are located.

With both disconnect relays ON, when a charge voltage from any source to either the chassis or house batteries reaches 13.4v the isolator relay will engage and charge both house and coach batteries from the charging source.

In your case, the way to check whether both chassis & house battery is receiving when charger is connected to either the chassis or house batteries you need to turn both disconnect switches ON.

You then connect the charger to either house or chassis battery, then, with a volt meter check the voltage on the battery(s) not connected to the charger.

If you get a voltage reading of 13v or more, then both battery banks are being charged.

It's important to periodically check the water level in all batteries and add distilled water when needed.

Regarding a solar panel, if your coach sits out where it's exposed to sunlight, then yes, a roof solar panel can be used. However to keep both chassis & house batteries charged you'll probably need an 80 to 100 watt panel with a controller to charge and maintain both banks of batteries. I would recommend you have someone with the technical knowledge & experience install and wire a solar panel system should you decide to go that route.

Hope this helps, good luck and safe travels

mr300ce · 11-20-2011, 11:48 AM

Quote:

Originally Posted by Georgia

my coach was designed from the factory to charge the chassie batteries from the engine alternator, and the house batteries from the generator/shore power. There is no interconnect between them. I was going to install a marine grade A/B/BOTH switch to be able to cross connect the batteries with the flip of a switch, but I ended up just getting a trickle charger for the chassie batteries that is connected to the generator/show power system. Works great.

cheers
geo

ps: all the batteries are 12V on my rig. 4 on the house side and 2 on the chassie side.

"I" believe you are incorrect about the charging of you batts. Every motorhome I have owned or seen charges ALL the batteries using the alternator when the engine is running. A "switch" disconnects the chassis batt from the coach (house) batts when the engine is not running, so as to not drain the starting batt.

But, with that said, many coaches have a parasitic draw on the starter batt (mine too) that will will, over time (long or shoart, depends on coach), drain it down.

When you are plugged into shore power, ONLY the coach batts charge. Same applies to the on-board (factory) solar charger. By the way, most factory solar panels are only large enough to "maintain" an already topped-up batt system.

In other words, if you drained your coach batts pretty low during the night thru your normal boondocking activities, it will take all "sunny" day, with out use, to top them back up. And that may not even bring them all the way up.

That's why I need to run my genset an hour or 2 each day or 2 boondocking, depending on TV/DVD use.

When I am on shore power or running the genset, I use the little jumper cables I made. They connect the coach batts to the starter batt. That way the starter batt stays fully charged, (not waiting for that 13.4v thing) and that little parasitic draw does not ruin my batt.

In my last coach, a Lazydaze 22ft, I used 2 of those Harbor freight solar panels (placed on the dash in the sun, to keep all the batts topped-up while the MH sat around waiting for me to use it. keep an eye on the wter in the batts, as even this little 'trickle charge' will evaporated it away.

Batt fact: starter batts loose months of life if you drain them way way down. You can charge them back up, and they may work fine, but you took months of life away from it, and it will die before that 'warranty' time runs out. They are supposed to be kept charged, ready to give you that massive amount of amps to crank that engine, at a moments notice.

Clay L · 11-20-2011, 12:02 PM

Your six volt batteries are connected in series to in effect make a 12 volt battery so it will be charged at 12 volts.

Gary RVRoamer · 11-20-2011, 03:26 PM

Quote:

When you are plugged into shore power, ONLY the coach batts charge.

Sorry to disagree, but that is true of some brands but not others. Fleetwood coaches do indeed charge the chassis batteries from shore power - they are always equipped with a relay that interconnects the house and chassis batteries once the house batteries are adequately charged by shore power. National RV coaches were designed the same way, but most Winnebagos are not. I won't try to answer this for all makes and models, but you get the idea.

captaindesmo · 11-20-2011, 03:52 PM

I have a 92 Fleetwood Bounder, gas. Has two battery switches near door. So my house bats will charge by generator or shore? or by alternator? I have to charge chassis bat, and house bats separately? I can charge the two 6v as if they are 1 12v w/12v 2amp trickle. Chassis bat is a 2 yo Optima red top that has no caps to fill with distilled water. last ime I charged it read only 12.7v then dropped 3v in 3 days. Does The MH have a built in 110 in 12 out battery charger somewhere, where is it? do I have to switch it on? How many amp hrs? Its raining today so I wont get over to it. but tomorrow I will check volts at chassis and house battery and report back. If I just plug in shore power it will charge bats? I have a ton of literature I got with the unit (just bought it, our first) but cant find answers to these questions, The Chevy chassis manual is useless, "How to operate your new bread truck"

captaindesmo · 11-20-2011, 04:10 PM

After reading Gary's helpful reply, can I assume it true I can connect a charger to house bats and when they are charged it will charge chassis bat? If I connect shore power it will charge "all" batteries, eventually? Will this take place with battery switches both off?

GaryKD · 11-20-2011, 05:01 PM

Hi Everyone,
What batteries are charged, from what source(s) and when is complicated and the answer is it all depends. If you can, contact the coach manufacturer for the answer. If that is not possible, consider posting the question in the iRV2 Owner's Forum for your Brand of coach. Nobody knows your coach like somebody who owns one just like yours.

If you have the time, skill and power source, you can connect the coach to shore power and take a VDC reading on the chassis and coach batteries.

wa8yxm · 11-21-2011, 09:18 AM

If you put a charger on your Main (or Aux) battreies will it charge the OTHER bank as well?

Depends on the isolator.. Mine will.. Many do not. And that is about all I can say.

How to find out.. you will need two DC volt meters. the plug into the 12 volt accessory socket jobs are fine for this.. With both showing normal battery voltage, or low battery voltage, hook up a charger.. If both come up to 'normal alternator" you are good. NOTE that may not happen right away... It may wait for the "Connected to charger" bank to fill up before it engages the other bank.

Old Bounder · 11-22-2011, 07:23 AM

Quote:

Originally Posted by captaindesmo

After reading Gary's helpful reply, can I assume it true I can connect a charger to house bats and when they are charged it will charge chassis bat? If I connect shore power it will charge "all" batteries, eventually? Will this take place with battery switches both off?

Leave the HOUSE battery switch ON if you have the rig plugged into shore power or if you are charging via the on-board converter/charger using the generator. Neither house nor chassis batteries will charge from the shore/gen power if the House switch is OFF. This description of how it SHOULD work assumes all components of the Battery Control Center (BCC) are functioning as designed.

Jim_HiTek · 11-22-2011, 04:58 PM

Haven't seen this mentioned yet...what many many people do when storing their RV's is to simply disconnect the battery ground cables. This ensures removal of all the parasitic loads that are even there if the 'Main' and 'Aux' switches are turned off (such as safety circuits...carbon monoxide sensor, LP leak detector, etc.). No shore power needed when you do that. No worries about the batteries for months.

The batteries should be fully charged before doing so...and as mentioned, if you've driven a few miles, the alternator will first charge the starting battery, then the BCC (Battery Control Center) will switch on a relay to allow it to charge the house batteries.

Many rigs don't charge the chassis battery when on shore power. To do that job I just installed a 'Float' charger ($20, 1.5Amp) and wired it to the chassis battery.

The solar panel that came with the rig is too weak so is worthless for much boondocking, or as a sub for the float charger. And it is wired ONLY to the chassis battery in my rig. So I ignore it.

buki · 11-22-2011, 06:10 PM

My Airstream is now 18 years old. I have never owned a battery charger, trickle charger or any other form of supplementary charging devices. Airstream was so technologically advanced that their design works even better today. Simply plug into shore power. Then turn on your auxillary battery switch. it will bypass everything (converter, inverter and isolator) in your electrical system and assure you of a full charge all of the time. Ut is just that simple. And a helluva lot cheaper. Newer models will never tell you that. But believe me, it works perfectly.

buki · 11-22-2011, 06:30 PM

Any manufacturer that didn't inform of you this technique is inevitably bankrupt by now...Monaco, Fleetwood, Country Coach and many more. If you start at the top like an Airstream...everything else will be second best. excuse my hubris but you get what you pay for. I spent $219,000 for my Land Yacht in 93. and today it runs better than ever. No slides, no garish full body paint designed by some idiot who considers himself an auteur, no fiberboard cabinets...it is what it is and that is perfect. DP, Allison 3060, everything works after 18 years and it is paid for many times over. try that with your 2011.