Battery not fully charging.

[JWL]

I hope me and my feeble electrical knowledge can explain this, but I am baffled.

I have 200 watt solar panel on the roof of my new FWC Hawk Shell. I have the standard 12V 79 Amp Hrs AGM battery.
Victron Smart Solar 100/20 controller, wired by cutting the FWC wires, wiring the ones marked solar to controller into the controller PV and the ones marked controller batt into the Battery ports on the controller.

With a volt meter at the controller I get 17.2 - 17.5 V at the controller from the panel, and 13.5 V on the batt side. This coincides with what the Victron connect shows.
But my volt meter and my BVM only shows 12.47 V. Putting a voltmeter on the batt only show’s 12. 4+- at the terminals.
The end result is my battery never gets fully charged 88-89% but the controller thinks it is. I can drive and it gets to 100%.

Any idea where or how I could be loosing that much juice from the controller to the battery?

 

[Vic Harder]

I'm assuming the distance between the controller and battery is short? Even if it wasn't, with that little current in the wire (on float) there should not be any measurable voltage loss.

Can you post a screen shot of your various settings screens on the MPPT and BMV?

In the meantime, if you are sure the batteries get to 100% while driving, do a synchronize and zero current calibration too.

 

[JWL]

I'm assuming the distance between the controller and battery is short? Even if it wasn't, with that little current in the wire (on float) there should not be any measurable voltage loss.

Can you post a screen shot of your various settings screens on the MPPT and BMV?

In the meantime, if you are sure the batteries get to 100% while driving, do a synchronize and zero current calibration too.

Thanks for getting back Vic,
Not knowing exactly where the wires go after coming into the battery box and then disappearing again I would imagine not that far before coming back to the battery.
Here are the screen shots and pics
My BVM is the AiLi, the set up is set fully charged batt to 100% and set amp hours. But it shows the same as the FWC meter.

And while I am googling what “do a synchronized and zero current calibration” means
I am assuming I have this correct but thought I should check. I have one battery cable off the bat negative to the shunt (B-) and the regular FWC installed battery negative wire on the other end of the shunt (P-)

 

[Advmoto18]

My first place to look would be at the state-of-health of the AGM battery. The OP did not state if the battery is new or repurposed for his camper.

Regardless, my first step would be to put the AGM battery on a bench and perform a load test; and you can only test an AGM once it has been verified fully charged.

AGM batteries should be load tested for 15 seconds at:
--1/2 the CCA rating (Cold Cranking Amps); and
--3 times the Ah rating (Amp hour rating).
--The voltage must not drop below 9.7 volts for the duration of the test.

Battery Conditions
12.65 V = 100% charge
12.45 V = 75% charge
12.24 V = 50% charge
12.06 V = 25% charge
11.89 V = 0% charge

Charging---never use an "old school" charger to charge an AGM. Using such will ruin an AGM battery in very short order. Charging current can not exceed 14.8V. Only use a "smart charger" on an AGM battery.

If the battery checks out OK, then I would start delving into by camper's electrical systems as it relates to the battery.

 

[AWG_Pics]

We just got back from a 3 and 1/2 week trip to southern Utah and a short dip into Arizona. I was quite worried initially because our batteries were hovering around 11.9 for a couple of days. But after a week they were charging to 12.7 consistently and never had a problem after that, even when we just stayed put without driving for a couple of days. Batteries are about 1 year old. The truck and camper did not move much all summer, but got a good workout over the last month (details and pics will follow in a week or so in a separate report.)

 

[JWL]

I may have it figured out but I am looking for some clarification.
the FWC video on installing solar talks about a battery wire, and a a load wire. Stan talks about cutting the wires marked solar panel (after the roof and remotes wires junction. He says to attach the panel wires to the PV ports and the other end to the battery ports on the controller. I did all that.
In his video the load wires were in that “wad” of wires, those were black and wire wires. I did not have those wires. Fastened up in my battery compartment was another set of wires that are red and black. The label was missing on one and the other is wound tight and looks like it says battery controller. I thought those were the load wires.
I got to thinking (trouble, I know) that what I assumed what Stan said were battery wires that are the main battery wires were possibly the wires from the controller that should be attached to the battery? I checked with a meter and the showed the same voltage as the battery side of the controller. (Apparently I don’t have any “load” wires? )

If this is the case it is apparent that is why there is no charge going to the batts. I don’t want to hook it up and get some weird circular circuit going or something. I am also wondering if FWC has changed the wiring since the video. So I’m hoping that someone with a new FWC, this is a Hawk Shell model can take a look at the wiring and see if there is in fact a wire coming from the back wall by the furnace (if you have one) to the battery.
I do have an email into FWC but they might be off today.
Im also praying that I haven’t damaged the controller, but it does seem to be doing it’s part.
Thanks again!

 

[Vic Harder]

I don't have a new Hawk to check this for you; however, let's do some troubleshooting.

First off, do you know for sure which wires are coming from the solar panels? If you disconnect all the wire pairs, in sunshine these will be the wires with way more than 14v on them. They should be going into a wire connector that also goes to the portable panel plug (if you have one... usually on the back wall of the camper). Check there to see if that portable connector has the same 14+ volts on it. If so, yeah! One set of wires identified for sure.

Next, let's figure out what goes to the battery. With all wires disconnected from your controller, and with the factory kill switch in teh OFF position, measure the battery voltage. Then find the pair of wires in the compartment with your MPPT that has the same voltage on them. Other than the solar panel wires, nothing else should have any power on it. These should be your battery wires.

Finally, the wires going to your kill switch/fuse panel. Right now nothing should be ON in the camper, with no voltage at the fuse panel either. Check that. This is where I am not sure about the wiring, as there are a number of options in how this could be wired. There should be at least one pair of wires near the MPPT that are also completely dead. If you turn ON the power with the KILL switch, these wires might go LIVE and have 12.6 volts or so on them. If they do, then these either the wires that will go to the BATT output on the MPPT, or they might be the LOAD wires.

I'm guessing here, but IF you have two such sets of wires, one might be the so called "load" wires. If your MPPT doesn't have a set of "Load" outputs, don't worry about these wires. Cap them off if necessary to prevent shorts, since I would think that they will be "hot" when the wires that go to the fuse panel are hot too.

I hope that helps.

 

[Advmoto18]

Excellent points Vic!

Especially tracing the wires from the panel AND the remote panel receptacle on the back exterior wall of the Hawk. An easy way to verify the fixed and remote panel wires as they do come together behind the MPPT (on my '15 Hawk).

AWG_Pics... 11.9V is a VERY low state-of-charge for most batteries. Other than a LiFePO4, a battery state of charge below 50% vastly reduces its useful life span. Many SME articles and web sites will confirm such.

 

[AWG_Pics]

AWG_Pics... 11.9V is a VERY low state-of-charge for most batteries. Other than a LiFePO4, a battery state of charge below 50% vastly reduces its useful life span. Many SME articles and web sites will confirm such.

I was plenty worried, but checked them again yesterday. They were at 13.0.

I don't want to rush to judgement, but I suspect a metal fry pan that got well-intentionally but accidentally rearranged into the wiring behind the controller by someone just may have been the cause. Lucky to have found it a day or two afterwards. Lessons learned by everyone!

 

[JWL]

PROBLEM SOLVED!
Thanks to Aaron at FWC. Apparently the Videos showing Solar installation are old. They are no longer putting Load Wires in and the wires from the back are the continuation of the wires from the controller. Hooked them to the battery and was 100% in just a few hours.

Thank you Vic for your methodical approach, but I had a feeling (as stated above) that this was probably going to be the case. And having everything set up and apparently working, my lazy self did not want to undo everything and risk screwing something up.

Thanks to all

 

[Vic Harder]

glad it is working for you now... and I've had the opportunity to work with Aaron before as well... top notch fellow.