Having trouble with new BestGo 12v 400amp LiFePo4

[Katie33kate]

Yes, I understand. Thank you for taking the time. I’ll make the changes at dawn. if it is working what changes can I expect to witness?

Have you considered writing a tutorial on the Daly BMS? I have found on internet searches there is NO user guide or any other written help.

 

[Katie33kate]

Spent this evening digging and educating myself…I think. Found a couple utube videos. Read some.
I have concluded that the changes seem like good ones. However, I found nothing on Strings.

I notice on the main screen there is this
Battery Strings : 4

yet, within the parameters is this setting
Battery Strings

which is left blank..yet shows 4 on the main screen.
what does this mean? I found no information on this at all.


I am guessing that by reset the BMS you mean getting physical access to it? This won’t be possible before next Tuesday. I think I would prefer to not change the battery strings parameter until I understand it, assuming I even can. But the rest of the settings will be ready for dawn.

would you be willing to contribute (lots) to an attempt here to discuss every parameter and setting? Sort of a line by line talk about what it means. Something that is specific to the Daly BMS. Sort of create a specific pinned post …users guide to the Daly sort of thing?

 

[sunshine_eggo]

Spent this evening digging and educating myself…I think. Found a couple utube videos. Read some.
I have concluded that the changes seem like good ones. However, I found nothing on Strings.

Maybe you should write the tutorial now...

I notice on the main screen there is this
Battery Strings : 4

yet, within the parameters is this setting
Battery Strings

which is left blank..yet shows 4 on the main screen.
what does this mean? I found no information on this at all.

Might mean 4 cells in the string, which is consisted with a 12V battery?

I am guessing that by reset the BMS you mean getting physical access to it? This won’t be possible before next Tuesday. I think I would prefer to not change the battery strings parameter until I understand it, assuming I even can. But the rest of the settings will be ready for dawn.

would you be willing to contribute (lots) to an attempt here to discuss every parameter and setting? Sort of a line by line talk about what it means. Something that is specific to the Daly BMS. Sort of create a specific pinned post …users guide to the Daly sort of thing?

No. I'm not competent to do so.

 

[Katie33kate]

My thinking on battery string is to take it literally.
each “string” would have a directly wired connection to the BMS. Makes sense if I I configure it this way:

4 actual cell packs assembled….wired in parallel to add up to 3.2v 400 amps.
Each of these are then treated as a “battery”. Wired in series to get to 12.6. 400 amps. System total.

hence the BMS would see 4 Make sense? if is a simple fact of how it is wired, the parameter setting is immaterial.
that would also explain why we see the voltage appropriate for 3.2v (nominal). Ie: ”battery” and not 12.6v

perhaps the setting in parameter is no longer used? I did not see that parameter in any documentation or any video tutorial.

what Do you think?

 

[sunshine_eggo]

Certainly makes sense. Not sure if it's right.

 

[Katie33kate]

Well…. always a new wrinkle:

each parameter I change, after pressing SET…. The change is not reflected. entered the password, but it does not change the status.

then..that “active balance” on/off button is greyed out and I cannot turn it on.

is this locked? Any idea how I enable that button…or make changes?

 

[Katie33kate]

Update. For whatever reason each parameter change requires a reboot to be effective. Can’t even do 2 at a time.

good-grief

so….I made those changes…but I decided to leave balance start volts at 3.2. Just so it happens sooner. Changed the balance diff .050 to .010.

I notice that the battery code and software version flash on an off …. Seems to happen with every change of The battery voltage in the string. Is that an indicator of every time balancing is active? So far, it is keeping a good control of the balance. Maybe it just wasn’t turning on enough before? Maybe all those reboots woke it up? Well..until it gets close to 13.8 I won’t be able to see a difference from previous days.

 

[sunshine_eggo]

Update. For whatever reason each parameter change requires a reboot to be effective. Can’t even do 2 at a time.

good-grief

so….I made those changes…but I decided to leave balance start volts at 3.2. Just so it happens sooner. Changed the balance diff .050 to .010.

I notice that the battery code and software version flash on an off …. Seems to happen with every change of The battery voltage in the string. Is that an indicator of every time balancing is active? So far, it is keeping a good control of the balance. Maybe it just wasn’t turning on enough before? Maybe all those reboots woke it up? Well..until it gets close to 13.8 I won’t be able to see a difference from previous days.

Please set to 3.40. Starting at 3.2V is not doing any good as cell deviations are minimal in the working range and balancing may be counter productive.

 

[Katie33kate]

Sadly, the behavior of the battery has not changed. The vendor believes the imbalance I am seeing in just battery #2 is really a bad battery.
so, I am working on figuring out how to get the replacement battery. Shipping it is a nightmare.

 

[sunshine_eggo]

Sadly, the behavior of the battery has not changed. The vendor believes the imbalance I am seeing in just battery #2 is really a bad battery.
so, I am working on figuring out how to get the replacement battery. Shipping it is a nightmare.

It's unlikely that you would notice any change if passive balancing is active. If it's still not tripping over-volt at 13.8V, that's a good sign. Balancing may take several days or weeks due to the small amount of current and the limited time above 3.40V/cell.

 

[Katie33kate]

I’ll watch it every day. So far, not change at the 6 hour mark on absorption. Still…battery #2 showing .25 above the rest. Then it comes back into balance once charging stops altogether. Been the same for the last 3 days.

ill have lots of time to see that change if it will happen..it looks like about 3-4 weeks for me to get the new battery.

 

[sunshine_eggo]

I’ll watch it every day. So far, not change at the 6 hour mark on absorption. Still…battery #2 showing .25 above the rest. Then it comes back into balance once charging stops altogether. Been the same for the last 3 days.

ill have lots of time to see that change if it will happen..it looks like about 3-4 weeks for me to get the new battery.

I'm finding it hard to believe the balancing is active.

 

[Katie33kate]

Well….as I approach 13.8, I see battery #2 running up to about 3.58 while the other batteries remain in the range of 3.43 to 3.46. But, as the hanging stops…once I am back to 13.4 the batteries are all within .01 of each other once again.

I’ll get screen shots today.

 

[sunshine_eggo]

Well….as I approach 13.8, I see battery #2 running up to about 3.58 while the other batteries remain in the range of 3.43 to 3.46. But, as the hanging stops…once I am back to 13.4 the batteries are all within .01 of each other once again.

I’ll get screen shots today.

Again, I want to emphasize that the return to 0.01V at lower voltage is expected even on a severely imbalanced cells. This does not in any way indicate balance. If this doesn't occur, something is likely catastrophically wrong with the battery.

I'm actually encouraged by your numbers:

Cell 2: 3.58
Cells 1,3,4: 3.43-3.46

Compared to:


While #2 is higher than the initial, the others are at or above 3.43V. This ensures your battery is AT LEAST attaining 95%+ SoC.

 

[Katie33kate]

That is interesting. I know from my usage that I am nearly 95% by end of day. My power use is so high that I wouldn’t make it through the night otherwise. I have long ignored the SOC indicator on the monitor….

so, now all I can do is wait for the new battery to arrive. About 4 weeks!! But, it looks like I shouldn’t have any real worry in the meantime.

 

[littleharbor2]

That is interesting. I know from my usage that I am nearly 95% by end of day. My power use is so high that I wouldn’t make it through the night otherwise. I have long ignored the SOC indicator on the monitor….

so, now all I can do is wait for the new battery to arrive. About 4 weeks!! But, it looks like I shouldn’t have any real worry in the meantime.

A properly programmed shunt based battery monitor is a good way to know, with reasonable accuracy, your state of charge at any time

 

[Katie33kate]

A properly programmed shunt based battery monitor is a good way to know, with reasonable accuracy, your state of charge at any time

Just like a bank account….you have to set it from a known point. Not since multiple battery problems began last April (including replacement twice) have I had any monitor set to 100% to begin. Directions say to bring the battery to 14.4 then set the SOC. This battery cannot be brought to even 14.0 without triggering alarms. So…as I said I just ignore the SOC

 

[littleharbor2]

At least with my Trimetric you set your full absorb setpoint and it considers the battery full, then it counts down amps drawn out and counts up amps while charging. What is your charging setpoint?

 

[sunshine_eggo]

Just like a bank account….you have to set it from a known point.

You can actually find a point if you have either the ability to take the system offline for up to 30 minutes OR if you're willing to set SoC against a votage that's transitioning from charge to discharge or simply under a light load.

Something is better than nothing or just throwing your hands up and saying "since I can't do what's said, I can't do anything."

Not since multiple battery problems began last April (including replacement twice) have I had any monitor set to 100% to begin. Directions say to bring the battery to 14.4 then set the SOC. This battery cannot be brought to even 14.0 without triggering alarms. So…as I said I just ignore the SOC

This isn't an all-or-nothing situation here. You're allowed to think logically about it and draw sensible conclusions. There is enough information to get within a few %.

If all your cells are above 3.40V, AND the charge current into the battery is less than 8A, then you can be HIGHLY confident you are at or above 95% SoC. Setting to 95% or even 100% is perfectly reasonable.

Any of the following voltages at rest or under a small load could be used to set SoC:




Best part is if you use a loaded voltage, it's conservative, i.e., if you're at 13.3V under a 3A load, and you set your SoC to 90%, guess what? You're true SoC is over 90%, so the gauge is conservative.

 

[Katie33kate]

I have directions to set the battery monitor by pressing both the up arrow and down arrow at the same time…it then sets the value at 100. Of course, pressing the Up arrow only takes me up thru the monitor screens, and conversely down is down thru the screens. Nothing in the directions let’s me select the value…just what it is or reset to 100

so, I am mostly used to dealing with this as it is. When I am at 13.8 I know from experience that I have plenty to take me till dawn. That chart you posted is great! Confirms what I have been believing.

new battery is expected in about 2-3 weeks.