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Chassis battery charging


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I have a 1997 Windsor that seems like it may no longer be keeping the chassis batteries charged.

It has a Heliotrope RV-30 solar controller and dual battery charger, but it seems flaky. It often shows battery voltage between 17-38V, and the chassis and house batteries are connected backward (I.e. chassis voltage is from house batteries). 

I think it has a chassis battery trickle charger but it isn't labeled so who maybe it's not (pictured).

A couple months ago, the chassis batteries were too low to start the coach. We were in Crescent City, CA, it had been cloudy for a couple months and the infrequent sunshine was at a very low angle. The batteries were around 12.8V, so I hooked up a battery charger and got them charged up to 13.6V, and they started the coach. I checked a few days before we were leaving there, batteries were still good but we had plenty of sunshine the last couple weeks. 

We've now been in Medford a few days with lots of sun, no shade. I turned on the ignition to adjust the leveling jacks and noticed battery voltage was on the low side; enough to activate the gauges and run the leveling jacks but too low to start the motor. The Heliotrope had the "charged" light lit, so it wasn't charging. I turned on the ignition for about 30 seconds, and the Heliotrope decided to start charging. After 30 minutes of clearing out the cabinet to get a picture of the back of the Heliotrope, and looking again at the electrical items by the motor, the battery voltage at the dash gauge is now where it should be for a charged battery that will start the coach easily.

I'm thinking of replacing the Heliotrope with the Blue Sky Sun Charger 30, and adding a Trik-L-Start charger. But if I already have an apparently non-functioning trickle charger, I guess that should be removed. Anyone know what exactly is this unit?IMG_5452.thumb.jpg.54a5b249d025718326372f1885758c95.jpg

Also, what is the purpose of this device? The power wires come up from both sides of the auxiliary boost relay. The right side power goes to the chassis battery cutoff switch, and the left-side power leads to the house battery cutoff switch.

AIMG_5453.thumb.jpg.8a98926f007d45f88eda0b74d11270e8.jpg

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23 minutes ago, Gary 05 AMB DST said:

I would clean all the connections first. It looks very dirty.

Gary 05 AMB DST

Yes

Clean everything 👌

A spray can of electrical cleaner

Electric motor cleaner.

WD 40 ?

 

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Jim, that green box with a green light is the device that is supposed to allow charging of the chassis battery(s) while on shore (generator) power.  The light being lit should show the device is working.  On my 97 Dynasty, it was lit, but NOT working.  When it is lit, you should see the same voltage on either of the end terminals to ground.  That should be above 13.5 volts (depending on the charge stage you are in).  If you have over 13.5 volts on the chassis battery(s), then they are being charged.  You may have another problem causing the chassis battery(s) to discharge at a faster rate than they are being charged.  If you do not have the same voltage on both terminals to ground, then the device has failed.  Replacements are scarce, and very expensive.  It's better to get a Amp-L-Start or Trik-L-Start type device and replace that green unit entirely.

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2 minutes ago, waterskier_1 said:

Jim, that green box with a green light is the device that is supposed to allow charging of the chassis battery(s) while on shore (generator) power.  The light being lit should show the device is working.  On my 97 Dynasty, it was lit, but NOT working.  When it is lit, you should see the same voltage on either of the end terminals to ground.  That should be above 13.5 volts (depending on the charge stage you are in).  If you have over 13.5 volts on the chassis battery(s), then they are being charged.

Thanks, I'll check that out. My suspicion is that device may have failed or be failing, and the Heliotrope solar charging device is flaky. 

I've figured out that the other device is a battery isolator, which *also* allows charging current to push to both batteries, while isolating draw. Does the isolator only allow charging current to push to both batteries at bulk charge, I.e. over 14V? So float charge voltage doesn't go through the battery isolator? Otherwise it seems like the Trik-L-Start would be redundant.

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Jim, the large (often blue) device is an isolator, as you suspected.  But it is used ONLY when the main engine is running.  It takes the alternator output and divides it between the chassis battery and the house batteries.  It is only in play when the engine is running, and only used when charging from the engine alternator.  It is completely out of the circuit when the engine alternator is not running.  

Regarding the Solar.  You don't say, so I'm going to assume you have the single solar panel that Monaco used.  That panel was about 100 Watts, when new.  That solar controller (the Heliotrope) is a PWM (Pulse Width Modulation) type controller.  They are the least efficient controllers.  The 17- 38 volts you are measuring is the INPUT to the controller from the solar panel.  The controller then "massage's" that voltage to a level around 14.2 volts to charge the HOUSE batteries (as wired by Monaco).  As I mentioned, the PWM type controller is inefficient in taking that 17 - 38 volts and using all the related power to charge batteries.  A much more efficient controller uses MPPT (Maximum Power Point Tracking) to "massage" the 17 - 38 volts to squeeze every bit of power over all voltage conditions into your batteries.  All this said, that 100 Watt panel, is barely enough to keep you house batteries from going dead while in storage.  It was never enough to charge the batteries up - only to offset the natural discharge and the few item that always draw from the batteries (like smoke alarm, CO alarm, and other) from discharging the battery.  Unless someone has rewired the controller (doubtful, unless more panels were added, and then still not likely) it only charges the House batteries.  That "green" device was then supposed to charge the chassis batteries if the house batteries were above a certain voltage (around 13.5 volts).  So, theoretically it could keep both batteries from discharging, but in real world, it just wasn't enough.   

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