Chassis battery charging...

[dc73]

Shouldn't chassis battery get charged by being plugged into shore power? Shouldn't it get charged by running gen?
Both of these charging methods do successfully charge the house batteries, I have verified that.

I went to start my coach for The first time in a few weeks, dead. It has been plugged into short power continuously. I connected my multimeter to the chassis battery and it read approximately 11.6 volts. I started the generator and my house battery display shows house batteries charging from the generator, but the voltage on the chassis battery was staying the same. Thus the question shouldn't either shore power or generator charge the chassis battery?

In a slightly separate issue, while the multimeter was attached to the chassis battery and I could see the display, I activated the auxiliary boost switch and saw no jump and voltage. I'm guessing this means my solenoid needs to be replaced. I was able to attach a jumper cable from the house battery positive to chassis battery positive, saw an immediate jump and voltage on the multimeter and the engine started right up, effectively bypassing the auxiliary boost switch.

[Jim_HiTek]

Millions of RVs have no provision to charge the chassis battery from shore power. Millions of others come from the factory with a B.I.R.D. circuit which does that job. And of course there are the inevitable jury rig circuits, either DIY or from the factory, that have a timer that operate the AUX start solenoid after a length of time for the house batts to get fully charged...then it closes the AUX solenoid so the chassis batt can get charged too. The delay is basically for old batteries...want them to be fully charged before making the converter work hard when charging the chassis batt.

Many of us use either an Trik-L-Start or Amp-L-Start to keep the chassis battery topped off. You can also just use a simple 2.5 amp float charger wired to the battery and powered by some nearby 120Vac outlet or splice into a line.

It would help if you put your Year, Brand, Model, and Engine in your signature for more focused answers.

[Lt Dan]

You didn't specify the year of your Winnebago, but our '06 Itasca did not have a provision to charge the chassis battery from shore power. I added a Trik-L-Start at the boost solenoid to keep the chassis battery charged. It's an easy addition if yours doesn't have a trickle charger or BIRD system to keep it charged.

You may not have a problem with the boost solenoid. On some it's powered from the chassis batteries because it's powered when the ignition is on. If those are dead there's not enough power to activate the solenoid.

[rk911]

none of the three MHs we've owned since 1986 were provisioned to charge the chassis battery from the genny or shore power. on our second and current MH we added a Trik-L-Start which diverts a small amount of energy from the house battery(ies) charging circuit.

Mega TRIK-L-START Starting Battery Charger/Maintainer

[twinboat]

If your chassis battery is charged by the house system, It would go thru the same solenoid as the boost switch controls. That one solenoid serves double duty.

Change that and then test again. Of it still doesn't charge, then you'll need an add on device.

[Kenny Loney]

Originally Posted by Lt Dan

You didn't specify the year of your Winnebago, but our '06 Itasca did not have a provision to charge the chassis battery from shore power. I added a Trik-L-Start at the boost solenoid to keep the chassis battery charged. It's an easy addition if yours doesn't have a trickle charger or BIRD system to keep it charged.

Same solution for me. 06 Winnebago Outlook. I wired the Trik-L-Start to the chassis battery and plugged it in to a coach 120v outlet. When the coach is plugged in to shore power, the chassis battery is maintained. The Ford chassis battery only lasted about 13 yrs, obviously not compromised by the maintainer.

Ken

[cbeierl]

The OP's 2005 Adventurer as manufactured did not have any mechanism to charge the chassis batteries when on shore power or under generator. Winnebago started adding the Trik-L-Start to diesel pushers in 2006, but I don't believe anything was done on the gas side until more recently.

I would recommend adding the Trik-L-Start as recommended by others. (Btw, the current 'Mega' version now charges at twice the rate of the original version.)

[Ray,IN]

Cheapest method is to use jumper cables between battery banks during storage.

[dc73]

Originally Posted by Jim_HiTek

Millions of RVs have no provision to charge the chassis battery from shore power. Millions of others come from the factory with a B.I.R.D. circuit which does that job. And of course there are the inevitable jury rig circuits, either DIY or from the factory, that have a timer that operate the AUX start solenoid after a length of time for the house batts to get fully charged...then it closes the AUX solenoid so the chassis batt can get charged too. The delay is basically for old batteries...want them to be fully charged before making the converter work hard when charging the chassis batt.

Many of us use either an Trik-L-Start or Amp-L-Start to keep the chassis battery topped off. You can also just use a simple 2.5 amp float charger wired to the battery and powered by some nearby 120Vac outlet or splice into a line.

It would help if you put your Year, Brand, Model, and Engine in your signature for more focused answers.

I have the year make and model in both my garage and signature, I assumed those would show up on posts, sorry about that. 2005 Winnebago Adventurer 35A Workhorse W22

[dc73]

Originally Posted by twinboat

If your chassis battery is charged by the house system, It would go thru the same solenoid as the boost switch controls. That one solenoid serves double duty.

Change that and then test again. Of it still doesn't charge, then you'll need an add on device.

Here is a photo of the solenoid. The red wire on the left goes to chassis batt, the red wire on the right goes to house batt. When activating the dash switch for boost the solenoid gives an audible click as well as you can feel it by hand, so something is happening.

Would the question of the chassis battery gets charged through the shore power depend on whether the house battery aux cutoff is in on or off position? I have mostly been leaving the house system off (cutoff active) during storage. Today though while testing house batteries were on.

[cbeierl]

In case you haven't seen them, here are all of the Wiring Diagrams for your coach. Of particular interest are the Automotive Wiring Diagram and Chassis Electrical Box Assembly diagram. Page 9 of the Automotive Wiring pdf shows the Battery Boost Switch which is connected to the three wires LR, LS, and KE. Looking at the Wiring Identification Guide you can see the following:

LR / 14 YEL BATTERY MODE SWITCH (AUX START SWITCH) BATTERY MODE SOLENOID (AUX START SOLENOID)

LS / 12 YEL OVERCURRENT PROTECTION 20A BREAKER TYPICAL,COACH FEED GENERAL PURPOSE(BATTERY MODE, RADIO POWER,BATTERY CONDITION

KE / 14 YEL RUN ONLY POWER SOURCE GENERAL PURPOSE(RELAY TRIGGER, REAR AUTO HTR,DRL,MONITOR,ETC

In its normal position the Battery Boost Switch connects KE to LR, thereby activating the Battery Mode Solenoid to join the two battery banks whenever the engine is running. When depressed the Battery Boost Switch connects LS to LR, activating the Battery Mode Solenoid regardless of whether the engine is running or not.

[kb2ztx]

Trik-L-Start. Added to both mine and my parents. Best money spent

Mega TRIK-L-START Starting Battery Charger/Maintainer

[twinboat]

Originally Posted by dc73

Here is a photo of the solenoid. The red wire on the left goes to chassis batt, the red wire on the right goes to house batt. When activating the dash switch for boost the solenoid gives an audible click as well as you can feel it by hand, so something is happening.

Would the question of the chassis battery gets charged through the shore power depend on whether the house battery aux cutoff is in on or off position? I have mostly been leaving the house system off (cutoff active) during storage. Today though while testing house batteries were on.

Hearing and feeling it clunk doesn't mean it's actually making contact inside. Burnt contacts inside is the leading cause of failure.
Only a volt meter can tell.

[Jim_HiTek]

Originally Posted by dc73

Here is a photo of the solenoid. The red wire on the left goes to chassis batt, the red wire on the right goes to house batt. When activating the dash switch for boost the solenoid gives an audible click as well as you can feel it by hand, so something is happening.

Would the question of the chassis battery gets charged through the shore power depend on whether the house battery aux cutoff is in on or off position? I have mostly been leaving the house system off (cutoff active) during storage. Today though while testing house batteries were on.

If what you say about the wiring is true, then that solenoid, if it's the boost solenoid, is wired wrong. What you should have is one red on the top terminal, lets designate that one as CHASSIS BATTERY +, then you should have one red on the bottom terminal, lets designate that one HOUSE BATTERY +. What your post is saying is that the House and Chassis batteries are connected together all the time. They should not be. That's bad on the equipment which isn't designed for that.

You should chase those wires out to make sure they're going where we've now designated them.

That third big red wire, that one will be COMING FROM the Converter, which is just a fancy charger for the house batteries. It's not designed to be reverse powered by the alternator so it's connection should be on the HOUSE terminal.

What happens is you unplug from power when you plan on driving. You press the Boost switch, that solenoid closes, and parallels the two battery banks, house and chassis. This gives extra oomph to the starting motor to turn over that big engine. It's a 'MOM'entary switch so once the engine starts, you release it and let the Battery control center take over. What it does, once the engine is running, is measure the chassis battery that's being charged by the alternator. When the voltage reaches a certain level of charge, usually within a couple minutes, then it closes that solenoid and the alternator is now charging the house batteries while maintaining the charge on the chassis batteries. Since the converter isn't being powered by shore power, it doesn't get bothered by the alternators voltage there.

So now you're driving along charging both sets of batts, you reach your destination 6 hours later, shut off the engine, set up, and plug into 120 volt.

Now it's your converters turn to begin maintaining the charge on your house batteries. These batts supply power to nearly all your house circuits like the lights, the engine and tranni memories, the steps, the entertainment system components, all the 12 volt outlets your house may have, the refer circuits, the furnace circuits, the thermostat, perhaps the dash radio (most RVs have a dash switch that lets you turn on the dash radio while parked), and last but not least, all the safety circuits like propane and CO detector. That's a lot of stuff, takes a bunch of energy from the batteries, and has to run all night sometimes if you're dry camping which is what an RV is all about. Because of that, they are 6 volt batteries in series...deep cycle. So the converter is designed to charge up those batteries under the worst of conditions and to save money, most manufacturers buy a Converter (remember that device) that's suited to charge a depleted set of 6 volt deep cycle that came with the RV and not much more.

So that's why we have to add a device that senses when there's enough charge on the 6 volters and only when it's charged enough to bleed some over to the 12 volter(s). The Trik-L and Amp-L devices do that trick for you. Some upper end RVs do it using those devices or a B.I.R.D. (Intellitec's Bi-Directional Isolator Relay Delay circuit).

Note that you only have 3 big wires on your solenoid in that picture, that just means that the alternator is connected right at the 12 volt battery (usually through a giant fuse). Or, alternatively, it could be the converter is connected directly to one of the 6 volt + terminals. The other 6 volt + would be jumpered to the - of that battery since they are in series.

Clear as mud huh? The job these systems are doing is avoiding an overload on the alternator and the converter while allowing the most versatility with the batteries at the lowest cost either driving or parked at a campsite.