Charge Controller shows power from solar but isnt charging

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samso asked Nov 19, '20

Charge Controller shows power from solar but isnt charging

I have a smart solar 100/50 mppt connected to 2x 100ah battleborn lithium batteries. Something is wonky as of a few days ago, as I can see the 700wh generated today, but it did not actually send any of that power to the batteries. As you can see In the pictures below, the minimum battery voltage has shown 0.00 for the past few days since the problem started. Today I should of been able to nearly top off my batteries with the 700wh generated, but my state of charge and voltage only went down all day.

I updated the firmware to the most recent update for the mppt and Bmv right when this problem started. I have checked all my connections and everything seems fine. Hoping someone can spot something I may have missed! Thanks

MPPT SmartSolar

screenshot-20201118-203246.jpg (347.0 KiB)

screenshot-20201118-203224.jpg (431.9 KiB)

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klim8skeptic ♦ commented · Nov 19, 2020 at 07:35 AM

Discharged energy vs charged energy is right out of whack.

Do you have load negatives connected directly on the battery?

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Answer 1 · 2020-11-19T06:03:31Z

Trina answered · Nov 19, 2020 at 06:03 AM

Why is there no minimum voltage? Something might be backwards.

OR you have a big short somewhere -lots of power but it just can't charge the whole earth!? 0.00 "min battery" voltage?

Weird. Got any pics?

...You checked your shunt?

The BMS is blocking? Are you getting any heat? You have the MPPT set up for the Lithium? Did you move any of the positive leads from the shunt to the battleborns? The BMV needs to have access via the shunt to the positive side of things.

Probably need to post some pics and the MPPT settings from the app page (screenshot). If you take the BMV out of the loop for awhile is the MPPT working correctly?

I'd look for a short or ground where it shouldn't be.

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samso commented · Nov 19, 2020 at 06:35 AM

Here's some updated information, to start the batteries are not at 0.00 volts, they are functioning just fine heres a shot from the bmv showing that. There's isn't a massive short, the MPPT is not displaying it accurately for some reason.

I also don't see any reason the BMV would be blocking the input from the charge controller, I may be wrong though. Everything is set up correctly and has worked great up until a few days ago.

Interestingly enough when the MPPT charge graph started a new day it now correctly shows the minimum voltage as seen here:

Lastly here is a picture of the MPPT settings, everything was configured to exactly what battleborn provided to me.

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Answer 2 · 2020-11-19T17:39:07Z

Justin Cook answered · Nov 19, 2020 at 05:39 PM

Hi @Samso, welcome to the Community!

I'll note a few things:

1. 2 days ago your vbatt climbed to over 15v, and the BMS of your batteries shut down access to the batteries (as it should have). On other days, where minimum battery voltage shows 0.00v in the MPPT, this is also likely what happened: maybe not over-volting on those days, but some other aspect of your installation or charge sources is causing the batteries to shut themselves down for self-protection.

2. The BMV cannot block charging, it is only a monitor; the Battle Born BMS (battery management system) can block charging. This can be caused by over-volting, over-charging, over-discharging, over-temperature, or a short detected in the system.

3. You have your MPPT set to charge at the absolute maximum voltage accepted by your batteries; this is unwise, and I suggest that you dial down the charge voltage to 14.4v.

4. You furthermore absolutely should not have your float voltage set to 14.4v, it should be ~13.6v.

5. The combination of your overly high charge voltage and your overly high float voltage could easily be causing the BMS of the batteries to shut down; if you have any other charging sources in the system, you should check their settings as well.

I recommend that you check all your wiring for a possible short, bad crimp, or loose connection, dial back your charge and float voltages in the MPPT to bring them in line with the user manual's specifications for your batteries, and double-check all your system fuses/breakers to ensure that they are of a reputable brand (no Amazon knockoffs please).

For your reference, I am uploading the user manual for your batteries, in which page 2 clearly states the ideal bulk/absorption voltage is between 14.2-14.6v, and float voltage should be between 13.4-13.8v. Unfortunately, as with any company, not everyone in Battle Born's office is fully educated with regard to the appropriate settings for charging their devices, and if Battle Born truly recommended the settings you have currently in your MPPT, then regretfully you were given bad recommendations.

Battle_Born_Manual.pdf

battle-born-manual.pdf (386.2 KiB)

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Trina commented · Nov 22, 2020 at 12:20 AM

I second Justin. The only time I have seen 0.00V on my monitor for my battleborns was when I didn't have things set up correctly

It is important to note that the battleborn BMS will completely cut ALL power to themselves (but they can still be drained) when overloaded AND/OR being overcharge with too high voltage. And that will give a "false" reading if set up incorrectly as having 0.00V. (I think when drained too low they will still show voltage on the battery monitors so the ONLY time you will see 0.00V is when they cut out from being overcharged but I don't have the schematic or bms info in front of me and theoretically you might be able to drain the cells to a point that the BMS limits everything going out until a charge is going IN -I know some of the older BMS from custom builds could have this issue).

When I first installed my lifepo4's I had a similar issue briefly until I remembered that 0.00V reading means the BMS is cutting in and shutting off ALL power to the batteries disconnecting them from the system!

Which like Justin pointed out can be incorrect settings and simply too high voltages to allow normal charging to happen

And if you are triggering anything via the BMV or your a battery monitor to then take place (IE a generator kicking in?) You could further complicate things... In very interesting ways.

!

For sure your BMV might not be reading state of charge accurately if it keeps seeing 0v on your battery so that will need to be sorted out once you get the voltage (and potential shorts) adjusted correctly. I.E. don't have the BMV in the network UNTIL you solve this issue..

So there"s the clue -0.00V is a short and/or too high voltages on a lifepo4.

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