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 > Dashboard Alternator light

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eric1514

AZ ID

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Posted: 07/31/21 02:12pm Link  |  Quote  |  Print  |  Notify Moderator

I monitored all the goings on with a Victron 712 that was showing me chassis and house battery voltage at the same time. All I know is that both battery banks were receiving positive voltage. I didn’t think at the time to record any numbers. I just pulled over and turned off the panels. This was my first drive after installing them.

I really need to do more testing.


2006 Isata Touring Sedan 250


mr_andyj

Georgia

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Posted: 07/31/21 02:19pm Link  |  Quote  |  Print  |  Notify Moderator

This is a motorhome?

On trailers the rv batts are so far away and the wiring so small this is not an issue, so assuming you are motorhome and everything is close together...

You can just get a circuit breaker and disconnect the solar system from the vehicle starting battery/alternator when driving, but sounds like you want both to contribute when driving.

Another possible idea is to use a diode from the alternator to the rv battery instead of a solenoid switch. The diode will make you lose a little bit of amperage but should not be a big deal. The diode only lets current go one way, so maybe this will keep the vehicle computer from seeing the higher rv battery voltage. I have only used the diode to prevent the rv from discharging the starting battery, so someone else can chime in on more specifics related to this.

How is the rv battery connected to the vehicle? to the alternator, to the starting battery? I had mine connected at the vehicle starter (about 4 -5 feet of wire from the starting battery), which was basically connected to the battery as far as electricity goes. Never had the issues you mention.

BFL13

Victoria, BC

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Posted: 07/31/21 02:45pm Link  |  Quote  |  Print  |  Notify Moderator

You saw charging to both battery sets with the dash red light on but you don't know if the alternator was doing any charging then or all from solar.

After you cut the solar off and the light went out, do you get any charging to the house batts or just to the engine batt since you did this installation of the solar and monitor?

You need a test to measure if any alternator charging to engine batt with the light on and not confuse that with any solar charging.

Your Victron shows both battery sets so its wiring and shunt could be how the solar on makes the dash light come on if there is a wiring mix-up there.


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eric1514

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Posted: 07/31/21 04:17pm Link  |  Quote  |  Print  |  Notify Moderator

I feel like I'm wasting everyone's time here with a problem that I haven't fully investigated on my own and you all are asking questions I don't have good answers to, so I'm sorry and I appreciate the help.

Here comes a wall of text.

This saga started last year when I replaced the 2 group 24 batteries in my motorhome with 4 GC2s. The stock batteries were connected in parallel and had 2 positive cables and 2 negative cables connected to them. One set was for an inverter powering the entertainment system. I put those cables on buss bars and added one more positive cable on the buss running to the new battery bank and a negative cable from the battery bank to a shunt and from the shunt to the negative buss. All pretty straight forward and it all worked for a season. Really, you couldn't tell anything was different either when driving or on shore power. The only issue was it took forever to replenish the batteries if I boondocked and used 150 Ah up.

So I put 400 watts of solar on the roof. 2 200 watt panels in series. The cables for that run directly to a Renogy Elite 40 amp controller (the positive goes through a circuit breaker) and from the controller, the cables run to the buss bars (again, the positive goes through a circuit breaker). Pretty straight forward. There is also a 2000 watt inverter that is hooked up to the buss bar that powers one half of one outlet in the kitchen for stuff.

What I know. With limited testing, I get 30+ volts from the panels and the controller makes 14+ volts and I've seen as high as 16 amps. The controller's charging profile for flooded batteries specs 14.6v on boost. The specs for the Interstate batteries I have also suggest 14.6 volts for boost. I should get more amps, but I'm parked in an odd place and can't get noon day sun. I'm happy with it.

I also know that everything works without the solar panels on. The last trip I took was 400 miles up and back and I left the panels off because I had shore power at every stop. Monitoring with the Victron showed both the chassis and house batteries being charged while we traveled and while we were parked. If I was to always leave the panels off when I travel and only turn them on when I park, everything would look normal. But I shouldn't have to do that.

What I don't know. I'm still not convinced that Ford didn't program the idiot light to show an over voltage condition. It would make sense to do so, but arguing against that is that more people would be having the same issue I'm having and not too many are. But, how many coaches have the Intellitec Battery Control Center installed? This thing will connect both battery banks when it senses either one of them getting a charge. So traveling without solar, the relay is open because the chassis battery is receiving voltage from the alternator and allowing juice to flow to the house batteries. That works. I'm positive. When the panels come on line, the juice from them is allowed to go forward to the house battery and perhaps Ford never anticipated 14.6 volts appearing at the starter battery in 2005. I don't think the alternator is allowed to output anything above 14.4, but I could be wrong.

What I also don't know is if changing the controller's charging profile to Lithium (14.4 boost-no float) or Gel (14.2 boost-13.8 float) will solve this. I hope so. I simple test would let me know.

Again, I need to do more testing but it's not convenient right now.

BFL13-->Does your solar system charge your chassis battery also?

* This post was edited 07/31/21 05:02pm by eric1514 *

BFL13

Victoria, BC

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Posted: 07/31/21 05:56pm Link  |  Quote  |  Print  |  Notify Moderator

Thanks for the background info, it helps. You have a puzzle there!

In my C the solar just charges the house batts. I do get alternator charging also to the house batts whenever I turn on the ignition, via an isolator. I do not have a boost switch to use the house batts to start the engine, but (I am not sure) they might do that anyway since the ignition would be on then, but with a dead engine batt, maybe the run circuit would not be live to close the isolator. Hmmmm, have to look at that.

Anyway, you also have that monitor that links both battery sets so it could be a suspect. I just have a Trimetric monitor on the house batts.

I have a friend with a 2007 C that has one of those boxes by the house battery that contains the isolator and some other fuses etc, not sure how it all works. My isolator is up by the engine battery.

I just can't figure how the solar can make your red dash light come on, and then how you can test for any alternator charging when both batts are getting charged, maybe only from solar. Weird.

I do think something is wired wrong, but can't think what it could be. That dash boost switch might be part of this if it is stuck closed. You would always get house batt voltage to the engine batt that way, but no red light.

Can you try it with solar but without the Victron? Or at least with the Victron's connection to the engine batt disconnected?

pianotuna

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Posted: 07/31/21 06:52pm Link  |  Quote  |  Print  |  Notify Moderator

Hi,

Replace the isolator relay with a dc to DC charger. That way the solar won't back feed the alternator charging path. As a bonus there may be even better charging of the house bank.

Add a by pass switch for charging the chassis battery when you are stationary, so that solar and shore may service it.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

eric1514

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Posted: 07/31/21 06:54pm Link  |  Quote  |  Print  |  Notify Moderator

This is the manual for the Intellitec Battery Control Center.

Intellitec Battery Control Center

It's too complex for me to mess with but the bottom line is that it allows any charging source, ie solar, generator, shore or alternator to flow to all batteries as it deems necessary. And it will pass high voltage and big amps.

From that manual
Quote:

The charging circuit, (which utilizes an isolator solenoid to connect the two batteries together for charging) will charge both batteries if either battery is being charged. It operates by sensing the voltage on the main and auxiliary batteries. If either voltage goes above 13.3 volts (the minimum necessary to fully charge a battery) for more than about 14 seconds, the isolator solenoid will pull in, charging both batteries. If the voltage falls below 12 volts for more than 4 seconds while the ignition is on, the isolator relay will open, keeping all of the alternator's output available for the chassis functions. If the ignition is off and the auxiliary battery voltage should drop below 12.8 volts (voltage of a fully charged battery) for 4 seconds, the isolator relay will open, preventing the coach loads from discharging the main battery.


It would be nice if I could disable the chassis battery charging from the solar while the alternator is running but I'm not that smart. I'm going to study the wiring diagram but this is not my line of work.

I wired a solar system up with a battery management system similar to yours without any issues. I also installed a Trik-L-Start to charge the chassis battery to that MH with no issues, but that thing is very low amps. I also installed a Trimetric in that MH with a wire allowing me to read the voltage of the starter battery. (The Trimetric is a better meter than the Victron, BTW, but that's another discussion).

I will investigate the dash boost switch. There's a possibility it's wired wrong. I can also disconnect the starting battery voltage sensing wire from the Victron, but that thing is tiny. It's also a 10 sec job so I'll do it.

I've got a question posted on a Ford Truck forum right now about the dashboard charging light behavior. That is, does it signal over voltage as well as under voltage and it so, what is the threshold.

Unfortunately, I can't get the MH uncovered until at least a week. It's too **** hot here.

Thanks for your help/interest,
Eric

eric1514

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Posted: 07/31/21 07:27pm Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

Hi,

Replace the isolator relay with a dc to DC charger. That way the solar won't back feed the alternator charging path. As a bonus there may be even better charging of the house bank.

Add a by pass switch for charging the chassis battery when you are stationary, so that solar and shore may service it.


Thanks.

I'd love to, but I don't where to start. The Intellitec Battery Control Center is too complex for me to decypher. Here's a picture.

[image]

I wouldn't know where to start.

BFL13

Victoria, BC

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Posted: 07/31/21 07:41pm Link  |  Quote  |  Print  |  Notify Moderator

Please keep us informed! An interesting puzzle for sure.

Not clear on why a boost button at all when the control centre does that anyway. Also you have a Trimetric with shunt on the engine batt plus the Victron reading the engine batt's voltage but no shunt, which is on the house batts?

Any way there can be confusion with the two monitors on the engine batt that might light up the red lamp when solar is on but not when solar is off?

Too many moving parts for my tiny mind! [emoticon] I would still worry whether the engine batt is really getting charged with that light on. I would want a second opinion (multimeter) besides whatever the Victron is saying via your phone.

Best of luck solving the puzzle!

eric1514

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Posted: 07/31/21 08:14pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

Please keep us informed! An interesting puzzle for sure.

Not clear on why a boost button at all when the control centre does that anyway. Also you have a Trimetric with shunt on the engine batt plus the Victron reading the engine batt's voltage but no shunt, which is on the house batts?

Any way there can be confusion with the two monitors on the engine batt that might light up the red lamp when solar is on but not when solar is off?

Too many moving parts for my tiny mind! [emoticon] I would still worry whether the engine batt is really getting charged with that light on. I would want a second opinion (multimeter) besides whatever the Victron is saying via your phone.

Best of luck solving the puzzle!


No. I guess I wasn't clear. This coach has only the Victron and my old coach had only the Trimetric. I prefer the Trimetric and almost wish I had gone that route in this coach.

I'll definitely keep this thread updated with what I find out. The RV is parked along side my house under a cover but until we get a week of sub 90 degree weather, I ain't unwrapping it. It was 101 today.

Thanks again for your help.

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