Community Forums

Blake 28BHS · 08-13-2021, 08:26 PM

Hi All - long time lurker.

I have a made in 2018 Mountain Series 28BKS travel travel. It’s been awesome. We had an Artic Fox before and had an awesome experience with that TT too.

I have a 170 solar panel on my roof, two Tojan t105 batteries. My solar doesn’t seem to be charging. I’ve never had solar before. When I look at my batteries I have 3 positive terminal leads, one for the tongue jack, one for the converter and one for the solar I think. However, on the negative side I only have 2 leads, one from the battery to the frame and the other to the converter I assume. Shouldn’t I have 3 negative leads, an additional lead for the negative on the solar?

My zamp panel registers my panel and gives a colt read out but it doesn’t seem to charge.

Any thoughts would be greatly appreciated!!

Mark_K5LXP · 08-14-2021, 08:44 AM

What controller do you have? If it's got a display you should be able to put it into current mode and see amps flow when the sun is shining.

Mark B.
Albuquerque, NM

Blake 28BHS · 08-14-2021, 11:04 AM

Quote:

Originally Posted by Mark_K5LXP

What controller do you have? If it's got a display you should be able to put it into current mode and see amps flow when the sun is shining.

Mark B.
Albuquerque, NM

I have the DS-30a. It shows statistics but the charge of the actual batteries doesn’t seem to go up. Also, my battery status bar at the top isn’t static on a charge; rather it cascades through the 4 increments. I don’t know if that’s what it should do but the manual seems to state it should just show the current charge.

Thanks for the help!

creativepart · 08-14-2021, 11:33 AM

So, those are 6v batteries wired in series and assuming that your negative wiring is white (odd color for Neg). Everything looks correct.

You would need one positive wire from the solar charge controller to the POS terminal and one negative wire to the (serial) NEG terminal on the other battery. Which is what it looks like you have.

The two batteries together make one 12v battery - hence one pos and on neg wire from the solar charge controller.

Here's something to understand about a solar charge controller it senses your battery's voltage, obviously, and it adjusts your solar charging output to the battery just like any other battery charger.

If you attach any smart charger to your batteries when they are either fully charged or being charged by your converter or Tow Vehicle the charger will reduce the charge current to the batteries. Your solar charge controller works the same way - it's a smart charger.

If you have a PWM solar controller it first reduces your solar panel output to ~12 volts (battery voltage) and then it turns on and off the power being sent to the battery. If you you are charging via shore power or your running TV then that solar charge controller is mostly OFF.

If you have a MPPT solar charge controller it makes full 18+ volts available to the smart charger inside the controller and it uses charging phases; bulk, absorption and float to moderate the power being sent to the battery for charging. So, that means if your batteries are fully charged or being charged by your converter/TV the smart charger in the MPPT controller provides only a small amount of charging amps to your batteries.

The other thing to know about this system - your T105s are great, heavy duty deep cycle batteries and as such they are slow to accept a charge. If they are in a low state of charge and your solar is the only thing charging them then you need to be patient and give them a long time to recharge. If you want them to charge faster you need more solar panels, more amp-capable controller and heavier wiring.

Lastly, be sure you have at least 10 ga wire from the charge controller to the batteries. If it is a longish run then it should be 8ga or thicker wire depending on the length of the run. And obviously, at least 10ga from the roof to the controller.

People that are new to solar think of it like flowing water - as long as the sun is shinning the power is flowing. Well, it sort of is... but your charge controller is taking that power and doling it out only as needed, not in a continuous rush.

PS. With 170 watts of panels the MAX charging current you can send to those batteries is ~10 amps in an hour. But keep in mind that's an ideal that is never achieved for any length of time. So, you're putting maybe 7 amps per hour perhaps 6 to 8 hours a day into the batteries and a full charge would require 220 amps.

Blake 28BHS · 08-14-2021, 02:05 PM

Quote:

Originally Posted by creativepart

So, those are 6v batteries wired in series and assuming that your negative wiring is white (odd color for Neg). Everything looks correct.

You would need one positive wire from the solar charge controller to the POS terminal and one negative wire to the (serial) NEG terminal on the other battery. Which is what it looks like you have.

The two batteries together make one 12v battery - hence one pos and on neg wire from the solar charge controller.

Here's something to understand about a solar charge controller it senses your battery's voltage, obviously, and it adjusts your solar charging output to the battery just like any other battery charger.

If you attach any smart charger to your batteries when they are either fully charged or being charged by your converter or Tow Vehicle the charger will reduce the charge current to the batteries. Your solar charge controller works the same way - it's a smart charger.

If you have a PWM solar controller it first reduces your solar panel output to ~12 volts (battery voltage) and then it turns on and off the power being sent to the battery. If you you are charging via shore power or your running TV then that solar charge controller is mostly OFF.

If you have a MPPT solar charge controller it makes full 18+ volts available to the smart charger inside the controller and it uses charging phases; bulk, absorption and float to moderate the power being sent to the battery for charging. So, that means if your batteries are fully charged or being charged by your converter/TV the smart charger in the MPPT controller provides only a small amount of charging amps to your batteries.

The other thing to know about this system - your T105s are great, heavy duty deep cycle batteries and as such they are slow to accept a charge. If they are in a low state of charge and your solar is the only thing charging them then you need to be patient and give them a long time to recharge. If you want them to charge faster you need more solar panels, more amp-capable controller and heavier wiring.

Lastly, be sure you have at least 10 ga wire from the charge controller to the batteries. If it is a longish run then it should be 8ga or thicker wire depending on the length of the run. And obviously, at least 10ga from the roof to the controller.

People that are new to solar think of it like flowing water - as long as the sun is shinning the power is flowing. Well, it sort of is... but your charge controller is taking that power and doling it out only as needed, not in a continuous rush.

PS. With 170 watts of panels the MAX charging current you can send to those batteries is ~10 amps in an hour. But keep in mind that's an ideal that is never achieved for any length of time. So, you're putting maybe 7 amps per hour perhaps 6 to 8 hours a day into the batteries and a full charge would require 220 amps.

Quick question for my own knowledge. Where does the negative wire from the solar controller terminate? If I have 2 negative wires at the battery; one going to the converter and the other going from the terminal to the frame as a ground. Where does the solar controller negative terminate?

Also the battery meter on the solar controller doesn’t state the battery charge; it just cascades up from, 0, to 1/4,1/2,3/4 to full then repeats. All the videos I’ve seen of this controller show it staying static at the charge level.

Thanks for the help and the time!

creativepart · 08-14-2021, 02:33 PM

The NEG wire from the Solar Charge Controller terminates at the Main Negative shown in the photo below and the POS wire from the Solar Charge Controller terminates at the Main Positive shown in the photo below.

Remember there are two "boxes"... but it's only one 12v Battery. One terminal on one box becomes the Positive and one terminal on the other box is the Negative. The other two terminals on the two 6v batteries are connected together - this is serial wiring to make one 12v battery our of two 6v batteries.

creativepart · 08-14-2021, 02:40 PM

Do you have the Zamp charge controller? I can't find anything with that model name... DS-30a. What brand is it.

This is the Zamp 30-amp solar charge controller:

Blake 28BHS · 08-14-2021, 03:27 PM

Quote:

Originally Posted by creativepart

The NEG wire from the Solar Charge Controller terminates at the Main Negative shown in the photo below and the POS wire from the Solar Charge Controller terminates at the Main Positive shown in the photo below.

Remember there are two "boxes"... but it's only one 12v Battery. One terminal on one box becomes the Positive and one terminal on the other box is the Negative. The other two terminals on the two 6v batteries are connected together - this is serial wiring to make one 12v battery our of two 6v batteries.

That make sense to me and I thought the same thing. The question I have is one of those wires at the NEG terminal is grounding to the trailer frame. The other is going to the converter. That’s why I thought there should be three at the negative terminal.

Billinwoodla · 08-14-2021, 03:27 PM

Blake, if you’re worried about panel output, you can attach a multimeter to each panel and check the voltage and amps. I recently suspected i had a panel that was off and sure enough, it wasn’t putting power out. The nice folks at Renogy are replacing it on their 25 year warranty.

Blake 28BHS · 08-14-2021, 03:39 PM

Sorry this is the controller I have. Finger slip on the last one.

creativepart · 08-14-2021, 04:09 PM

Quote:

Originally Posted by Blake 28BHS

That make sense to me and I thought the same thing. The question I have is one of those wires at the NEG terminal is grounding to the trailer frame. The other is going to the converter. That’s why I thought there should be three at the negative terminal.

Yes, the chassis would be grounded at the Main Negative terminal and so would a converter ground because the converter is also your battery charger.

What I don't understand in your question is... where do you get three? Did you think you needed a neg from the solar charge controller to go to the battery, the converter and the chassis? Is that the three you asked about?

The answer is a definite no to that if that's what you mean. Those other things connect directly to the Main Negative terminal... just like your solar charge controller should.

OK, that's the charge controller I thought you meant initially. The Zamp controller. In your photo you've attached it's showing the battery voltage. I thought you said it wouldn't show you the voltage?

By the way, 12.6 v is for intents and purposes a fully charged or 95% charged battery.

You are off to a very good start with all of this stuff. You'd probably be happier with a 2nd 170w solar panel if you have room for it. And, I'd highly recommend a shunt-based Battery Monitor.

It's about $140 for a really good one that puts all of the details about your battery on your smart phone. And, it's pretty easy to install. Instead of using voltage to determine your battery's state of charge (SOC) it counts all power into and out of your battery. And, it shows you your accurate SOC in percentages.

https://www.youtube.com/watch?v=_GjcGZsK4fI

Blake 28BHS · 08-14-2021, 04:29 PM

Quote:

Originally Posted by creativepart

Yes, the chassis would be grounded at the Main Negative terminal and so would a converter ground because the converter is also your battery charger.

What I don't understand in your question is... where do you get three? Did you think you needed a neg from the solar charge controller to go to the battery, the converter and the chassis? Is that the three you asked about?

The answer is a definite no to that if that's what you mean. Those other things connect directly to the Main Negative terminal... just like your solar charge controller should.

OK, that's the charge controller I thought you meant initially. The Zamp controller. In your photo you've attached it's showing the battery voltage. I thought you said it wouldn't show you the voltage?

By the way, 12.6 v is for intents and purposes a fully charged or 95% charged battery.

You are off to a very good start with all of this stuff. You'd probably be happier with a 2nd 170w solar panel if you have room for it. And, I'd highly recommend a shunt-based Battery Monitor.

It's about $140 for a really good one that puts all of the details about your battery on your smart phone. And, it's pretty easy to install. Instead of using voltage to determine your battery's state of charge (SOC) it counts all power into and out of your battery. And, it shows you your accurate SOC in percentages.

https://www.youtube.com/watch?v=_GjcGZsK4fI

Yes that was my question; seems it should only be 2 by your answer. I thought it should be 3 at the negative terminal, ground converter and solar. But I guess from your answer there is another negative somewhere else that the solar is terminated. I just don’t understand where.

My controller always shows a voltage, it’s the status bar for the battery I don’t understand. It flashes through all 4 status and doesn’t just hold at the current charge level like I’ve seen in all the videos of the controller.

Thanks again for taking the time.

ByeTheWay · 08-14-2021, 04:37 PM

Here are some links to help with solar knowledge:
RV Electrical
https://handybobsolar.wordpress.com/
The 12volt Side of Life (Part 1)
http://solarpanelsvenue.com/mixing-solar-panels/
solarseller.com alternative energy by John Drake Services, Inc.

creativepart · 08-14-2021, 04:46 PM

Quote:

Originally Posted by Blake 28BHS

Yes that was my question; seems it should only be 2 by your answer. I thought it should be 3 at the negative terminal, ground converter and solar.

Yes, if your setup has two cables on the Main Neg terminal before the solar controller is connected then it should have three cables on there after.

I've been trying to figure out what it is you're asking.

I'm certainly not telling you to connect the solar charge controller's negative cable anywhere else but the Main Negative Battery terminal. So, however many cables are connected there you should have one more with the addition of the solar charge controller.