Connecting Victron MPPT and BMV

[marter]

Hello,

I'm questioning the way I've connected my Victron MPPT controller and BMV monitor. I'm getting voltage readings from the MPPT but no amps/watts.

Some background; I've installed a Renogy 100w panel on the roof using factory 10ga wires and have a Renogy 100w suitcase, both connected to a Blue Sea switch and then the MPPT Smart Solar 100/20 controller. I'm getting the same readings (around 22v but 0 amps/watts) from either solar panel or both, using the Blue Sea switch. Below is a diagram of my connections, along with a screenshot from the Victron MPPT.

When I check the readings at the input posts of the Blue Sea switch I'm seeing 21.8v and 5.08a, and I'm seeing voltage from the MPPT app so I'm assuming it's not cable shorts. I'm also seeing the MPPT controller go from Bulk to Absorption to Float, but not seeing any charge going to the battery when looking at the BMV app.

Currently the 30a ANL fuse is blown (due to my meter probes touching), and I'm going out tomorrow to replace it and keep troubleshooting, but I was getting the same results prior to the blown fuse.

I believe I have enough voltage difference to produce watts to the batteries so I'm assuming I've connected something wrong or have something set wrong in the MPPT configuration.

Any ideas or comments?

Thanks in advance,
Mike

[Totlh]

1) Make sure your polarity is correct coming from your solar panels to the Charge controller.

2) Your solar panels will only produce power if it has a place to go. Make sure your batteriess are not already fully charged. Your picture shows your batteries are on float. Put a load on them, unplug your unit from shore power.

3) Make sure your panels have plenty of sun hitting them.

BTW your picture is very hard to see, maybe it is just this laptop I'm using.

Hope this helps.

[GMFL]

Are you connected to shore power, because if you are the solar will not charge due to the converter/charger keeping the batteries topped off.

[marter]

Thanks for the reply. I've traced the polarity all the way through, and based on the readings I'm getting at the Blue Sea switch (the last jump before the MPPT controller) I believe they are correct.

The panels are producing over 5 amps so I think the sun is strong enough. It may be the charge on the batts; I'm unplugged from shore power and turned on all the lights (they're LEDs) to produce a load on the batts of 6.1a per the screenshot below, taken during these tests. Maybe it's not enough drop in the battery.

As far as the attachments, I assume you're clicking on them to enlarge them. If not, please try that. If they're difficult to read, I'll upload larger versions.

Thanks,
Mike

[Crackerman]

If your anl fuse is blown, the solar charger won't output current.

Jump the fuse or replace it, log in with Bluetooth and check it out.

You can also set parameters of your batteries in the charge controller.

If your voltage is over 12.9, in most cases the controller won't charge.
Run batteries down to 60 percent or so, then the charger will give it all it has.

[marter]

The same conditions existed before I blew the fuse. I'm replacing it tomorrow and will keep troubleshooting.

So it's normal to see a 22 volt reading on the MPPT app but 0 amps/watts even when the battery is charged?

Can anyone else confirm this?

Thanks,
Mike

[wulfraat]

Originally Posted by marter

The same conditions existed before I blew the fuse. I'm replacing it tomorrow and will keep troubleshooting.

So it's normal to see a 22 volt reading on the MPPT app but 0 amps/watts even when the battery is charged?

Can anyone else confirm this?

Thanks,
Mike

No, normally you will see a float charge with a couple amps current when the batteries are full.

Have you programmed the mppt and bmv for lead acid charging profile with the correct bulk/absorption/float voltages?

Have you paired your mppt to the bmv using Bluetooth networking (assuming they are both current generation smart devices)?

[AirMiles]

It appears everything is connected and working properly to the Blue Sea switch. Maybe the Amps are just not being displayed on the Bluetooth interface but the controller is outputting Amps since you see the bulk/absorption/float stages. I would check the Amps with my clamp meter going into the battery. Under any daylight condition my system has Amps going into the battery, even when floating. I do not have a BMV, so I'm unsure what effect that may have on your displayed Amp readings.

[pgeller]

Is it possible the controller in the portable panel is interacting with the input to the MPPT controller? Can you try disconnecting the portable?

pg

[uncle_bob]

Hi

Assuming the two screen shots are both at the same time:

The MPPT thinks there is 13.8 V on the battery.

The BMV thinks there is 12.41 V on the battery.

This simply can not be true. One or the other is not wired in properly. It's a good bet that the MPPT has a fuse or wiring issue. A check with a multimeter would also be a way to work out which one is right ( two votes just shows a problem, three votes breaks the tie).

Bob

[marter]

Originally Posted by pgeller

Is it possible the controller in the portable panel is interacting with the input to the MPPT controller? Can you try disconnecting the portable?

pg

The portable doesn't have a controller. They're both running thru the Victron.

[marter]

Originally Posted by uncle_bob

Hi

Assuming the two screen shots are both at the same time:

The MPPT thinks there is 13.8 V on the battery.

The BMV thinks there is 12.41 V on the battery.

This simply can not be true. One or the other is not wired in properly. It's a good bet that the MPPT has a fuse or wiring issue. A check with a multimeter would also be a way to work out which one is right ( two votes just shows a problem, three votes breaks the tie).

Bob

Agreed, Bob. I think it's the MPPT controller that's the problem. I'm seeing the same voltage as the BMV when I check the battery terminals, so the MPPT voltage is not right, and I dont know where it's coming from.

The Victrons are networked and passing the voltage and temperature from the BMV. Just to check I unplugged the BMV and the MPPT still reports the higher voltage.

AMSolar told me something interesting today. At 22v I'm not producing any charge, and that i need to see 18v which means its producing a charge. I'm measuring amps at the blue sea switch posts and the wiring into the controller, but I'm not sure this a valid reading with multimeter probes. I probably need a clamp ammeter.

Btw AMSolar is baffled so far, so it's not just me. Probably time to try a different controller.

Thanks for the replies,
Mike

[uncle_bob]

Originally Posted by marter

Agreed, Bob. I think it's the MPPT controller that's the problem. I'm seeing the same voltage as the BMV when I check the battery terminals, so the MPPT voltage is not right, and I dont know where it's coming from.

The Victrons are networked and passing the voltage and temperature from the BMV. Just to check I unplugged the BMV and the MPPT still reports the higher voltage.

AMSolar told me something interesting today. At 22v I'm not producing any charge, and that i need to see 18v which means its producing a charge. I'm measuring amps at the blue sea switch posts and the wiring into the controller, but I'm not sure this a valid reading with multimeter probes. I probably need a clamp ammeter.

Btw AMSolar is baffled so far, so it's not just me. Probably time to try a different controller.

Thanks for the replies,
Mike

Hi

The MPPT is reporting the voltage on the output terminal of the charger. Everything it is saying is 100% consistent. All of the numbers make sense *if* the output wire simply isn't connected. It could be as simple as a wire falling out of the screw clamp.

The simple check is to take the multimeter and measure the voltage at the MPPT output terminals. If the meter agrees it is 13.8V then the MPPT is doing fine. The wire is "open" between there and the rest of the world. If the meter shows 12.4V then either a wire is missing or the controller is broke.

Keep in mind that the grounds are just as important as any other leads in this case. An open ground will do this the same as an open supply wire. Hooking the output line to the "load" terminal would be another way to get those readings .... lots of things to check.

Bob

[marter]

Well, the little things can kill ya. Checked the fuse in the MPPT controller again and could barely see the break but it was blown. Replaced it and all is good now. Thanks for the replies.

Happy trails again,
Mike

[uncle_bob]

Originally Posted by marter

Well, the little things can kill ya. Checked the fuse in the MPPT controller again and could barely see the break but it was blown. Replaced it and all is good now. Thanks for the replies.

Happy trails again,
Mike

Hi

Checking fuses by eye can be really tough.( = I've missed them the same way) Putting the multimeter in the ohms mode is a more reliable way to do it.

Bob

[marter]

Great point, Bob. Reading glasses and lights help also, but I'll remember your tip next time. Would've saved a lot of grief.

Happy trails,
Mike