MOD Silverleaf Charge Bridge Limitation / Workaround

[flyboy013]

The charge bridge (bidirectional isolator relay) in my Mountain Aire is control by the Silverleaf TM102 module as opposed to an Intellitec BIRD that I believe is installed in the Dutch Star and below models.

When Silverleaf senses a low chassis battery voltage it engages the charge bridge solenoid (assuming the coach has AC power) so that the chassis battery gets charged too. Silverleaf only activates the charge bridge for 1 hour. I’ve tried changing the Silverleaf configurations but to no avail.

The problem is that 1 hour of charging isn’t long enough to get the chassis battery charged from 12.4 volts (Silverleaf trigger) back up to 12.8+ volts. Thus I would find that my charge bridge would activate several times a day as the voltage on my chassis battery drops.

This becomes more of an issue when I’m boondocking, as the generator would run before quiet time to charge the house batteries. If the chassis battery is at 12.5 volts, the charge bridge would not engage and the chassis batteries aren’t able to take advantage of this limited charging time. By morning (end of quiet time), my chassis batteries are lower than the 12.4 volts that would kick in charging. A few times I have found the chassis batteries below 12.0 volts by morning. (Parasitic power draw is a separate issue that I’ve looked into. That’s for a possible future topic).

So, I decided I would create my own charge bridge controller and install it along side the Silverleaf capability. With a Sonoff SV device (less than $5), I was able to implement a smart switch to charge my chassis batteries at the “right time”. The Sonoff SV is merely a smart relay that is powered by 12 volts. When the relay is turned on, the 12V power is provided as an output which I have connected (along with the Silverleaf output signal) to the White Rodgers solenoid for activation. The Sonoff SV is installed in the cord reel electrical compartment and is connected to one of the many unused fuse slots. I installed Tasmota (open source ESP8266 firmware) and configured it to access my MQTT server (think smart home communications hub).

So now I have many ways that I can enable the charging of my chassis batteries. First off, I have Silverleaf with its logic. I can push the button the Sonoff SV to manually active the charge bridge. I can point my web browser to the Sonoff SV to turn the relay on. Best of all I can have my RV automation controller active the relay / charge bridge.

For the later, I have automations setup such that if the generator gets turned on, a message is sent to the MQTT server to have the charge bridge engaged. When the generator turns off, the charge bridge will turn off. I also have logic such that if the coach looses AC power (ie. unplugged) the charge bridge will turn off to ensure that the house doesn’t draw power from the chassis batteries.

Below is a picture of the install. The red glow is from the Sonoff SV LED showing that the relay is turned on. The case was 3D printed.

Here is a picture of the Tasmota webpage.

 

[Old-RV'er]

You could have called S.L sure they would have allowed you the password into system to change that parameter. Simpler to me than creating another "thing" I got to take care of. They were extremely helpful to me when I owned the APEX with S/L controlling everything in the house.

And now you have changed the system as provided by S/L and Newmar, so any long term warranty you had, is now gone. That may not be important to you, but if what you did causes a fire, your insurance company will not pay you for the MH if they discover you changed something like this. Now that also could be wrong if you worked with S/L, and developed this with them helping you. But if you did, I would make extremely sure, i have documentation for the insurance company in case bad things happen. And please understand I realize you are dealing with possibly relay's and microvolts and microamps. If you are wet, and get shocked, it takes less than 0.0001 amps to stop your heart. Just my two cents worth. Good job,

 

[flyboy013]

I have the password into the Silverleaf advanced settings. The Silverleaf system just doesn't provide the capabilities that I would like. Specifically to have the charge bridge activated whenever the generator was running as opposed to only when the voltage gets down to some preset level. (As well as to being able to control the duration of the charge bridge activation).

I installed all sorts of smart devices in my S&B home (as well as my coach). Some are made by others and bought on Amazon while other are DIY projects that are custom to my needs.

If I only installed Newmar or SL sanctioned devices, my coach wouldn't satisfy me. I've installed timer relays on various cabinet lights; added dimmer switches to over the bed reading lights; added LED light strings to various compartments; added electric waste values (that are remotely control), and have added a Smart RV system to monitor and manage the coach remotely.

I can see if there were mods that required a professional license to implement, that an insurance company may have an issue if something bad happened, but that isn't the case here.

Based on what you're saying, I shouldn't have changed my water pump or White Rodgers solenoid when they went bad, as I may have caused a fire.

I'm a retired software engineer and have worked on many electrical systems (to include some on USN ships) over the years. I have a good understand for my skill level and those things that are beyond my expertise level.

My goal was to put out information on system limitation and how one can overcome them. It's beyond the skill level for some, but not others. I'm confident with the workmanship of what has been implemented.

 

[Old-RV'er]

It's your rig, you paid for the privilege's of doing anything you want to it. But I would have at least checked with S/L, and maybe you did. Maybe that system cannot be "upgraded by them". Now you have solved their problem, see if they want to buy your improvement.

 

[flyboy013]

I had communicated with Art at SL about my various issues including the one which caused the KIB water pump buttons to no longer work. He was very helpful but at the time was unable to provide a solution to the problem. I have since learned from a forum thread that SL now sells a flyback diode for the White Rodgers solenoid to resolve the issue. It would have been nice if SL or Newmar had send out a technical bulletin about the problem/fix.

All in all, I’m happy with the support Silverleaf has provided, but they don’t always have the ability to provide solutions for everyone’s problems. Thus the reason for some of my mods.

I’ve been working on various improvements to include my Smart RV capability. Perhaps this is something SL (or Newmar) will be interested. I had discussed it with Art many months back. If I have the opportunity to make to the Northwest, I plan on meeting them and having the discussions. In the meantime, I’ll continue to make improvements to suit my needs.

 

[Old-RV'er]

S/L folks are great, very helpful and friendly. Sort of hard to find, get directions from them some GPS's don't get it. Glad you were able to find info. Www.irv2.com/f104 (Alpine Forum), anyone on their who owns APEX model might be able to help you with S/L, although there setup is way different than NA's. A fellow on their called Engineer Mike, is the guru on many of those systems, nice fellow, have talked to him lots of times and even worked with him at an Alpine Rally installing some mods to the steering gear box supporting structure (WRV went out of business). S/L I think has a forum as well, but don't hold me to that.

 

[WsklyWabt]

I had communicated with Art at SL about my various issues including the one which caused the KIB water pump buttons to no longer work. He was very helpful but at the time was unable to provide a solution to the problem. I have since learned from a forum thread that SL now sells a flyback diode for the White Rodgers solenoid to resolve the issue. It would have been nice if SL or Newmar had send out a technical bulletin about the problem/fix.

All in all, I’m happy with the support Silverleaf has provided, but they don’t always have the ability to provide solutions for everyone’s problems. Thus the reason for some of my mods.

I’ve been working on various improvements to include my Smart RV capability. Perhaps this is something SL (or Newmar) will be interested. I had discussed it with Art many months back. If I have the opportunity to make to the Northwest, I plan on meeting them and having the discussions. In the meantime, I’ll continue to make improvements to suit my needs.

Quick question. The issue you were having with the KIB keypads not controlling the water pump, did that ever get resolved? I'm having the same problem on my 2019 New Aire. Silverleaf works properly and KIB's pads in water closet and kitchen don't. KIB Rel-5 relay in rear closet can be heard operating and pulls to ground but pump does not come on. Any insight would be appreciated...

 

[flyboy013]

If you reboot the TM-102 that will get the KIB panel water pump buttons working again. I have rebooted by disconnecting and reconnecting the MAIN connector on the TM-102 module. I recall others saying that there is a fuse, but I’m not personally familiar with it.

The problem occurs due to the lack of a flyback diode on the charge bridge which causes a reverse voltage spike to the TM-102. Some have reported damage to the TM-102 requiring the device to be reprogrammed or replaced. I have not experienced this.

This problem occurs with the White Rodgers solenoids and I understand Newmar uses a different brand now that has a built in flyback diode. You can add the diode. You can buy one from Silverleaf or make one yourself. It’s just a 10 cent diode with wires added to each side.

 

[WsklyWabt]

If you reboot the TM-102 that will get the KIB panel water pump buttons working again. I have rebooted by disconnecting and reconnecting the MAIN connector on the TM-102 module. I recall others saying that there is a fuse, but I’m not personally familiar with it.

The problem occurs due to the lack of a flyback diode on the charge bridge which causes a reverse voltage spike to the TM-102. Some have reported damage to the TM-102 requiring the device to be reprogrammed or replaced. I have not experienced this.

This problem occurs with the White Rodgers solenoids and I understand Newmar uses a different brand now that has a built in flyback diode. You can add the diode. You can buy one from Silverleaf or make one yourself. It’s just a 10 cent diode with wires added to each side.

Thanks much. Will give the reboot of TM-102 a try. Fingers crossed.
Added the flyback diode to the solenoid right after coach purchase so have that one covered. Has been frustrating trying to track this one down. Newmar had me looking for a conventional water pump controller, which isn't used, and wiring schematics for troubleshooting these coaches are apparently nonexistent. What was the thinking behind that one?

 

[turbopilot]

The Silverleaf system just doesn't provide the capabilities that I would like. Specifically to have the charge bridge activated whenever the generator was running as opposed to only when the voltage gets down to some preset level. (As well as to being able to control the duration of the charge bridge activation).

Just waking up this topic. Thanks for your posts on the flyback diode. Have not had any problems but I will install the diode.

The way I solved the issue of charging the chassis battery when I want to versus when the TM102 decides to allow charging the chassis battery was to simply swap the spring loaded battery boost switch with a regular two way switch. With that easy modification I charge the chassis battery on my terms. I have 1 kw of solar on the roof. Silverleaf will not activate the charge bridge anytime I am running on solar/batteries, so I simply "turn on" the charge bridge to the chassis batteries manually during this mode of operation.