Having trouble with new BestGo 12v 400amp LiFePo4

[Katie33kate]

This is a long story. But..I bought the above mention battery. It has the built in BMS and blue tooth. I love being able to see what is going on with this.

first time I tried to fully charge (on my system it is 14.2) I got a fault alarm at 14.0. The blue tooth shows battery 4 getting overcharged.

this is all inside one complete package. Plug and play

well..long story short, I tried this…. I set absorb to 13.97. it dropped into absorb BUT still continued to charge to the 14.0 with the resulting alarm

so, I set absorb time to 0. It the. Drops into float and maintains the battery voltage at 13.5 till sunset.

subsequent tests show that the capacity (at 13.99v) is enough for all my off grid needs.

why can’t I just run like this? It would be at least 5 weeks before a new battery would reach me…..and it might even make more sense for me to drive to Salt Lake next month and get it. But, meanwhile?????

 

[sunshine_eggo]

when it shut down at 14.0V, what were the 4 cell voltages?

Recommend you lower absorption to 13.8V and absorption time to 6 hours.

Raise float to 13.6V.

Even a very small imbalance can contribute to a runaway cell at or near full charge. The BMS should slowly balance the cells in the above configuration. About every week or so, increase absorption by 0.1V until you can get to 14.2V.

If you can configure the BMS balancing function, set to balance at or above 3.40V and if there is a difference of 0.02V or more.

 

[Katie33kate]

Absorption will bring that battery above 14.0. In just a few minute. Tried it. Sets off the alarm. is there a setting on the victron MPPT that lets me set max absorption? I only saw time.

 

[sunshine_eggo]

 

[Katie33kate]

Equalization voltage is grey out and disabled….same with tail current.

?

 

[sunshine_eggo]

That's fine. Make the changes you can.

 

[Katie33kate]

I have set those parameters….I’ll watch it today.

so, are these new settings designed to balance that one battery That is tripping the fault alarm?
I thought that was the “job” of the BMS. If this is correctable that would be perfect.

for curiosity sake….what did you do so that those parameters that disabled because accessible on your MPPT?

 

[littleharbor2]

View attachment 105076

Am I missing something here? I see 4854 watts of incoming power. Divided by 14 volts is 347 amps. Is your PV array really this large for a 12 volt battery bank?

 

[sunshine_eggo]

Am I missing something here? I see 4854 watts of incoming power. Divided by 14 volts is 347 amps. Is your PV array really this large for a 12 volt battery bank?

Victron Connect using demo library. Numbers are simulated, but in Demo mode, you can pretend as though you have VC connected to that piece of hardware.

I have set those parameters….I’ll watch it today.

so, are these new settings designed to balance that one battery That is tripping the fault alarm?

Yes.

I thought that was the “job” of the BMS. If this is correctable that would be perfect.

It is; however, the balancing capability of most BMS is very very very small. It's only designed to maintain a balance. Attaining balance can take awhile. Most BMS passive balancing functions can only drain about 1Ah/day from a cell.

for curiosity sake….what did you do so that those parameters that disabled because accessible on your MPPT?

Demo library. I don't know why it's disabled in your setup. It's generally enabled or can be enabled. I can change it in my 250/100. It's only used for flooded lead acid batteries, so it's fine that it's disabled.

 

[Katie33kate]

At 10:30 the MPPT switch to absorption…. Holding steady at 13.6.

below is a screen shot of the BMS at noon. (1 1/2 hour into absorptio)

notice the one battery is now high But, not high enough to trip the fault

how many days do you think it will be before this all balances out? I worry that at 13.6 I will not have enough for the night. Right now I removed most of the load … but can’t do that for many days in a row.

 

[sunshine_eggo]

Did you mean to say 13.8V? The sum of the 4 voltages is 13.75V.

13.8V with a long absorption period (6 hours) will get your battery to >98% SoC provided it doesn't trip over-voltage.

The indicator at the top right suggests the BMS isn't balancing. Please screencap your configuration that includes balance parameters.

 

[Katie33kate]

yes, bulk to 13.8. Then once in absorption it dropped to 13.6.

as for that switch you see…balance….it is greyed out, I cannot change it.
the seller has no users guide…when I ask for one I just get a shrug…can’t get one.

yeah..sort of working blind here. I will never recommend these people again.

so…will this balance with this method? How many days do you figure?

 

[sunshine_eggo]

yes, bulk to 13.8. Then once in absorption it dropped to 13.6.

There is no difference between bulk and absorption voltages.

Bulk mode means it will charge at the maximum available current until the bulk/absorption voltage is reached.
when the bulk/absorption voltage is reached, that voltage is held and current tapers.
Once the charge termination criteria have been met, it drops to float.

Are you in float or absorption?

Absorption should be at 13.8V if you configured as instructed.

If the battery has a physical voltage display, I don't care about that. Any time I refer to a voltage, it's the values reported by the MPPT and the BMS.

as for that switch you see…balance….it is greyed out, I cannot change it.
the seller has no users guide…when I ask for one I just get a shrug…can’t get one.

yeah..sort of working blind here. I will never recommend these people again.

so…will this balance with this method? How many days do you figure?

As I already indicated, there is no evidence balancing is active, thus that answers the above two questions. The answer is "NEVER" since balancing is not active.

Again, please include screencaps of your configuration that includes balance parameters. If you have no idea what I'm talking above, please provide screencaps of every screen you can access. Starting points are indicated by the yellow circles:

 

[Katie33kate]

Ok…. First 2screens are active balance , then followed by the screens from preferences

 

[Katie33kate]

Oops….here is preferences

 

[sunshine_eggo]

Try 2A. If it doesn't work, try setting battery strings to 1 if 0 doesn't work:

 

[Partsjockey]

I can not believe how helpful the people are on this site. I'm so glad I found you guys!

 

[Katie33kate]

Ok…can you tell me what balance current is. Balance string? What do those mean?
what is the effect of the values for balanced open start and balanced open diff? Guess I really mean..what do those parameters mean.

should I changes to just the values in active balance you indicate and turn the balance switch on…
or make all the changes at once? (Both in active balance and in parameters).

For the balance string….0 or 1. What does it mean: “If that doesn’t work”? does it mean I should see all 4 batteries in balance (within .1v) ?

sun is really low now…I’ll make the changes and set it for Dawn.

 

[Katie33kate]

Oh….and thank you so very much for all this help. You are a gold mine of knowledge!!

is there a guide to this Daly BMS somewhere? Obviously I am sorely lacking in knowledge.

 

[sunshine_eggo]

Ok…can you tell me what balance current is.

You have a DALY smart BMS that appears to have active balancing. This is a very new feature. I'm not completely familiar with it, and I'm not entirely certain that your BMS actually supports it. I'm guessing that the balance current is the amount of amps it can actively balance. 2A is a reasonable value for a active balancer.

Balance string? What do those mean?

Not sure, but I'm assuming "string" as in a single string of cells.

what is the effect of the values for balanced open start and balanced open diff? Guess I really mean..what do those parameters mean.

Balanced open start means at or above 3.40V, it will start balancing if cell deviations exceed "balanced open diff," i.e., if cells are more than 0.01V apart, and a cell is at or above 3.40V, balance.

should I changes to just the values in active balance you indicate and turn the balance switch on…
or make all the changes at once? (Both in active balance and in parameters).

For the balance string….0 or 1. What does it mean: “If that doesn’t work”? does it mean I should see all 4 batteries in balance (within .1v) ?

sun is really low now…I’ll make the changes and set it for Dawn.

Make all changes as indicated at once.

Didn't explain myself well. Make all changes except for the "balance string" one. Leave it at 0. If balancing doesn't work, try 1.

You may need to reboot the BMS to make the changes take effect.

Want to reiterate that I am guessing. Please note the value of my advice in my signature.