Daly BMS problems... I think

[Daddy Tanuki]

I'd be concerned with shortening the leads, too, although I read somewhere in this forum it may not be that much of a difference. You can determine the resistance in the wire and calculate the voltage drop for the length. There should be almost no current running through the leads under normal operation, anyway. Maybe start a new thread with the question or search to see if the question was already answered somewhere. I think it was.

yeah I searched it before and got conflicting advice. I understand voltage drop.. trust me I am the king of wasting money to avoid it ha ha ha. I probably have the most efficient setup on this forum buts that's cause I have more money then brains at times and i nuke everything

 

[OTRwSolar]

Here's my only problem and why I really avoided top balancing even though I bought the recommended 10amp charger on here. I don't have shore power I'm completely off grid...I have a 6500watt predator gene but other than that the SLA batts I have it should be charge those then use them with inverter or gene with the 10amp charger. If Ido can I disconnect the BMS harness and put charge leads on each cell while they're still connected in series ??

I only have experience using the iOS bluetooth app, Overkill, and JBD Tools desktop apps with our JBD 4s 200a BMS. I'll offer what assistance I can.

I'm not familiar with the android JBD/Overkill app. Are you able to change/modify the *numerical* values such as low/high voltage cut-off?

Do you have USB access with your new Overkill BMS (need the optional USB module)? If so, I'd suggest using either the Overkill or the JBD Tools desktop apps to make your *initial* adjustments. It offers more flexibility (access to more parameters) than the iOS bluetooth apps (again, not familiar with the android).

FWIW, the Overkill balancer appears to be operating. You can see the "B" icon on the two cells with the highest voltage lit-up.

If your situation absolutely won't allow you to properly top-balance, in my opinion, an acceptable plan b would be the use of a Heltec-type 16s 5a active balancer ($70-$80 from several US dist on Amazon and eBay). Activate it when your cell voltages are above 3.400v. A Heltec 4s 5a active balancer balanced our 4s 200ah pack (which initially had a 250mv delta) down to 2-3mv (at 3.60v) in a few hours. Not sure how long it'll take the 16s 5a active balancer to do the same thing with your 16s pack, but it's certainly got to be 20-40 times faster the 100-150ma balancer on the JBD/Overkill BMS.

Good luck!

 

[DerpsyDoodler]

yeah I searched it before and got conflicting advice. I understand voltage drop.. trust me I am the king of wasting money to avoid it ha ha ha. I probably have the most efficient setup on this forum buts that's cause I have more money then brains at times and i nuke everything

Wish I had that problem...

So, what do you have to say on the subject? Here's an experiment: measure the voltage at the cell with a dmm, then measure it at the end of the sense lead with the same DMM. Seems like that should be pretty indicative outside of balancing, and should give an idea how shortening the lead will effect it. DMM with millivolt measurement? What's "good enough"?

 

[Daddy Tanuki]

Wish I had that problem...

So, what do you have to say on the subject? Here's an experiment: measure the voltage at the cell with a dmm, then measure it at the end of the sense lead with the same DMM. Seems like that should be pretty indicative outside of balancing, and should give an idea how shortening the lead will effect it. DMM with millivolt measurement? What's "good enough"?

good question, I have to wait until its warm enough outside that I can "uncover" my packs. currently they live under 4"s of b;lue foam with silicone heating pads heating my aluminum plates that act as a base, and as side compression walls. I am afraid to uncover them until the outside temps stabilize enough to prevent sub zero charging. sometime in the next two to three weeks the weather will change and it will go from 0°C to 5 or 6 C then I can pull the pack apart and investigate things like that.

weather really messes with me here. it jumps from freezing to boiling over the course of about 3 weeks. A matter of elevation coupled with location. So once it warms up a bit I can pull the pack apart and play with it safely. Its one of the reasons I avoided LiFePo4 cells until last year. Up to that I was straight up AGM as they are very temp stable... that and no BMS issues to concern myself with. So i guess I have a bit more study and for me, data that can be replicated. its one of the hallmarks of my work. (Welder/Fabricator, ships repair) Destructive testing as well as non destructive testing are the only way to me to get proof. unfortunately as much money as I have to spend on wiring and interconnects...it does not carry over to the cost of cells. getting old/cheap i guess.

 

[DerpsyDoodler]

good question, I have to wait until its warm enough outside that I can "uncover" my packs. currently they live under 4"s of b;lue foam with silicone heating pads heating my aluminum plates that act as a base, and as side compression walls. I am afraid to uncover them until the outside temps stabilize enough to prevent sub zero charging. sometime in the next two to three weeks the weather will change and it will go from 0°C to 5 or 6 C then I can pull the pack apart and investigate things like that.

Sounds like an interesting setup. Are you planning on building a roofed insulated enclosure (shed)? Something you could easily access during the cold heat or rain for maintenance should the need arise?

weather really messes with me here. it jumps from freezing to boiling over the course of about 3 weeks. A matter of elevation coupled with location. So once it warms up a bit I can pull the pack apart and play with it safely. Its one of the reasons I avoided LiFePo4 cells until last year. Up to that I was straight up AGM as they are very temp stable... that and no BMS issues to concern myself with.

yeah, young industry but maturing fast.

So i guess I have a bit more study and for me, data that can be replicated. its one of the hallmarks of my work. (Welder/Fabricator, ships repair) Destructive testing as well as non destructive testing are the only way to me to get proof.

Yeah, if you're under rare circumstances sometimes that's the only way. Even when you can learn from someone else's data, replicating it small scale as a PoC is still best practice.

unfortunately as much money as I have to spend on wiring and interconnects...it does not carry over to the cost of cells. getting old/cheap i guess.

I wouldn't call it cheap, I would call it good sense. Some of these companies charge a ridiculous premium that really isn't justified short of an absolutely no-questions-asked warranty.

That said, budget rack mount and other form-factor batteries are quickly catching up in quality and reliability. I like the experience of building my own pack, but if there's no significant monetary (or otherwise) advantage to doing so, ready-made it is. At least I have the experience under my belt of understanding, in full, the technology. There is a lot to be said for that.

 

[Daddy Tanuki]

Sounds like an interesting setup. Are you planning on building a roofed insulated enclosure (shed)? Something you could easily access during the cold heat or rain for maintenance should the need arise?


yeah, young industry but maturing fast.


Yeah, if you're under rare circumstances sometimes that's the only way. Even when you can learn from someone else's data, replicating it small scale as a PoC is still best practice.


I wouldn't call it cheap, I would call it good sense. Some of these companies charge a ridiculous premium that really isn't justified short of an absolutely no-questions-asked warranty.

That said, budget rack mount and other form-factor batteries are quickly catching up in quality and reliability. I like the experience of building my own pack, but if there's no significant monetary (or otherwise) advantage to doing so, ready-made it is. At least I have the experience under my belt of understanding, in full, the technology. There is a lot to be said for that.

I already built an insulated battery shed from when I started with AGM's, and while it can be accessed it is small as function=form. smaller is easier to keep warm. The cells them selves are packed in a 6 x 8 configuration. actually its three 2 x 8 packs lined side by side. as the entire pack is enclosed in one large foam insulating pack that is inside of a foam insulated building my battery warmers were actually surprisingly efficient.

but its too tight to get in and maneuver cells around easily, and still keep the cells warm. Kind of narrow and long as that was the best shape for my AGM's when I first built it.

the now newer rack mount systems are kind of exciting, but I have already invested a lot of cash into my individual cell setup, so I need to make it work or save up another year or two of spare cash to rebuild with the server rack style. hopefully I will not have to do that.

 

[DerpsyDoodler]

...the now newer rack mount systems are kind of exciting, but I have already invested a lot of cash into my individual cell setup, so I need to make it work or save up another year or two of spare cash to rebuild with the server rack style. hopefully I will not have to do that.

Of course. I wasn't suggesting replacing anything for the sake of replacing. Your investment should be good for at least ten years. I was just making the observation that if there's a need for expansion, not so sure going the DIY route would still be prudent. Even so, that still depends. All one can do is spec out and make a cost comparison when the time comes.

It's been nice chatting. I hope we haven't hijacked this thread with too much OT!

 

[YahwehisKing]

Bro your best bet is a solid top balance, even if you have to use a genset to do it. haul the batteries down to the closest place with power and the 10 amp charger you bought and pay someone for the power to top balance them properly. if you have your setting wrong they will never balance.
I have had one perfectly balanced pack go out of balance due to setting the balance settings wrong. if the setting are wrong you will slowly lose capacity (not permanently thank god) but what will happen is as the top and bottom get further apart, they will cause the BMS to shutdown to protect the pack. for instance if not in balance, one cell will hit 3.65 and shut off charging...and balance at the same time while one of the cells is at 3.35 (for instance) then with each succeeding cycle the gap will grow and you will get less capacity with each succeeding charge until you cannot charge at all.

TOP BALANCE PROPERLY, reload or update your app, it should show a voltage for each cell or pack. it should show one temperature and only one as you only have one temp sensor for the DALY BMS.

is you have a separate smaller battery pack that you can use, then use it at a reduced level to TOP BALANCE. I cannot say it enough...TOP BALANCE. once you have done that 90% of your issues should be eliminated. anything after that is an APP issue. I have 3 16s packs and on 2P4S pack as my backup power source. the 48 volt packs take care of the house, the 12 volt pack runs my battery heaters, I can use for TOP BALANCING or as an emergency backup (for the essentials) I use the same APP for both 16s and 4S packs this is on an I Phone. until last year I used a android but my phone self destructed and I used a friends old I phone to run things. there were differences in the APPS and I had some issues with the first APP i loaded for the android... I loaded a different app and all was good. I has some minor issues with the apple APP but overall it has worked to date, either will work if you get the correct app.

As always, good luck and keep asking questions, provide lots of photos and as much info as you can.

So I found this in Appendix C of the overkill BMS manual
"If the pack is already assembled in series, and you are unable or unwilling to start over, you can still balance
it with the regulated power supply.
● Connect a charger to the battery with the BMS installed normally. (charger positive to BC[max] and
negative to C-).
● Charge the battery until the BMS reaches a cell overvoltage cutoff.
● Open your Bluetooth app or desktop app and navigate to the individual cell voltages.
● Find the lowest cell and connect your 3.650v regulated to that cell only, in the correct polarity.
● Allow the cell to charge up to 3.650v.
● Repeat this process until every cell is fully charged to 3.650v.
● Now cycle the battery with a load then a charger to verify that the cells are sufficiently balanced.
● If the BMS still reaches a cell overvoltage before the battery is fully charged, repeat this process"
I'm going to try that method

As far as taking the pack somewhere...my closest neighbor is 5mi after that 10mi and town is 30mi away...everyone out here uses a gene and as far as I know I'm the second person to build a lifepo4 pack.... I also don't want to tear down the pack as I've noticed my positive terminal on my last cell is stripped but still tight so if I remove it I'll have to fix the threads.... ?

As for the Daly app I was using the most recent one offered in the posts here as well as the PC software. The JBD/overkill is working though

 

[YahwehisKing]

I only have experience using the iOS bluetooth app, Overkill, and JBD Tools desktop apps with our JBD 4s 200a BMS. I'll offer what assistance I can.

I'm not familiar with the android JBD/Overkill app. Are you able to change/modify the *numerical* values such as low/high voltage cut-off?

Do you have USB access with your new Overkill BMS (need the optional USB module)? If so, I'd suggest using either the Overkill or the JBD Tools desktop apps to make your *initial* adjustments. It offers more flexibility (access to more parameters) than the iOS bluetooth apps (again, not familiar with the android).

FWIW, the Overkill balancer appears to be operating. You can see the "B" icon on the two cells with the highest voltage lit-up.

If your situation absolutely won't allow you to properly top-balance, in my opinion, an acceptable plan b would be the use of a Heltec-type 16s 5a active balancer ($70-$80 from several US dist on Amazon and eBay). Activate it when your cell voltages are above 3.400v. A Heltec 4s 5a active balancer balanced our 4s 200ah pack (which initially had a 250mv delta) down to 2-3mv (at 3.60v) in a few hours. Not sure how long it'll take the 16s 5a active balancer to do the same thing with your 16s pack, but it's certainly got to be 20-40 times faster the 100-150ma balancer on the JBD/Overkill BMS.

Good luck!

So I let the overkill balancer work when it wasn't charging and now my cells look balanced but is that just the cells "resting" technically?
Yes the android app lets me change the numerical values of each setting see pic posted

I don't have and it didn't come with USB attachment but the Bluetooth hasn't given me complaints, except yesterday I was going over things and it kept locking the BMS but I found that if you enable charge and then discharge it unlocks....

I was thinking about an active balancer and also I read the part in Appendix C of the overkill BMS pdf and it has a method of top balancing when everything is still connected..

 

[YahwehisKing]

Sounds like an interesting setup. Are you planning on building a roofed insulated enclosure (shed)? Something you could easily access during the cold heat or rain for maintenance should the need arise?


yeah, young industry but maturing fast.


Yeah, if you're under rare circumstances sometimes that's the only way. Even when you can learn from someone else's data, replicating it small scale as a PoC is still best practice.


I wouldn't call it cheap, I would call it good sense. Some of these companies charge a ridiculous premium that really isn't justified short of an absolutely no-questions-asked warranty.

That said, budget rack mount and other form-factor batteries are quickly catching up in quality and reliability. I like the experience of building my own pack, but if there's no significant monetary (or otherwise) advantage to doing so, ready-made it is. At least I have the experience under my belt of understanding, in full, the technology. There is a lot to be said for that.

I do not agree with that last part. There is a significant monetary advantage to diy batteries still. The EG4 is 1500 offering 5kw purchase 3 to get 15kw at 4500$ +shipping freight + an inverter/charge controller or hybrid + the panels if you don't have enough or any. It'll run you at least 6500$ for ready made. I spent 2500$/w/shipping for 15kw of cells 16-280ah eve and 700 on a Growwatt hybrid. I have 10panels 100watt 12v mono renogy so no spend there but if I bought them new it would be about 1k so for my 15kw setup it was about 4200 that's a significant 2300$ savings sure you gotta minus wire and fuses but that brings the savings to 2k which is still pretty nominal.
I spent the last 3months making sure DIY was more cost effective even with the learning curve...

I also live in an are where people need someone and want someone that knows how to setup and build solar systems. I already do remodels so I saw DIY as a learning chance for a skill to increase ways of making money out here, it's a looked for skill out here with a large vacancy.

 

[YahwehisKing]

Of course. I wasn't suggesting replacing anything for the sake of replacing. Your investment should be good for at least ten years. I was just making the observation that if there's a need for expansion, not so sure going the DIY route would still be prudent. Even so, that still depends. All one can do is spec out and make a cost comparison when the time comes.

It's been nice chatting. I hope we haven't hijacked this thread with too much OT!

Why 10yrs?? Are we just doubling AGM expectancy and if it lasts longer saying Yayyyy?? I thought it was more in the realm of "you'll die before they go"

 

[Capt Bill]

I have a 16s 280ah build all new eve cells grade A so I didn't top balance -_- same reason as most now "brand new, grade A, will prowse recommendation and advice.." I'm using a 100amp 16s Daly with UART, and a 3k Growwatt lvm es I believe. I don't know if the BMS is dead a few things makes me think it's not, I get same voltage on P- and B-. The cell harness is correct and goes up in the correct increments, my Growwatt says it's charging, at first the solar was charging and then would rest and go and rest and go but with no errors or faults I disconnected everything and reconnected and there doesn't seem to be that issue any more . My thing is my Bluetooth app reads incorrect data and I can't connect via USB I can establish a port but no communication occurs so I don't know if the cells are being balanced or equally charged. I was reading the cells this morning and the last cell and first cell will read 3.5-3.7 whiler charging but the others at the same time are 3.45 and rising. I don't know if that's a problem and the BMS isn't working properly or what Ill attach pics

Just notice your picture with that AcuRite LCD Screen with arrow options (maybe to scroll through pages; Can you give us more info about that?) Might get me to try on a Daly Smart BMS, ... and figure out how you got that LCD configured (for my learning more all the time program). I am on two Chargry BMS8T(s) for my 24v LiFePO4 280 Ah x 2 ...Battery Bank. I really like having access to the battery info. and graphics on my two connected LCD(s) ( ... 6 pages of battery info. to scroll through, plus a configuration page with lots of changeable configuration options). I am Curious; and Fishing for Tips on that Daly connected LCD screen; how it works; and any config tips. I hope somebody starts a Daly Smart BMS FAQ thread soon. / maybe along side a JBD Smart BMS FAQ (which I see is popular here too) thread. ;+)

 

[DerpsyDoodler]

Why 10yrs?? Are we just doubling AGM expectancy and if it lasts longer saying Yayyyy?? I thought it was more in the realm of "you'll die before they go"

Would you like me to say 13.69 years? if the batteries are rated for 5000 cycles and you cycle them once daily, do the math. If you cycle them less, do the math, more, do the math. ;p That's a lot to say every time you want to say it. Bottom line is it depends on individual usage, but at 5000 cycles based on one cycle per day, 10 is a fair number.

 

[YahwehisKing]

Just notice the AcuRite LCD screen with arrow options (maybe to scroll through pages/ can you give us more info about that). Might get me to try on a Daly Smart BMS and figure out how you got that LCD configured. I am on two Chargry BMS8T for my 24v LiFePO4 280 Ah x 2 ...Battery Bank. I really like having acess to the battery info. and graphics on the two connected LCD (with 6 pages of battery info. to scroll through, plus a configuration page) and lots of configuration options. ..... I am Curious, and Fishing for Tips on that Daly connected LCD screen, and how it works, and any config tips. I hope somebody starts a Daly Smart BMS FAQ thread soon. ;+)

LMAO ohhhhhhh soooo sorry bro!!!!! That lcd screen is for my 5in1 weather station. The screen links to weather underground to give personal weather data https://www.wunderground.com/dashboard/pws/KNVRENO1006/graph/2022-04-11/2022-04-11/daily

Beside the word daily at the end of the link there is no connection to the DALY BMS

RaspberryPI is going to be the solution to that one, so far learning a lot of this stuff takes as much brain power as learning some C+ or java so with time someone will have it done.

 

[OTRwSolar]

So I let the overkill balancer work when it wasn't charging and now my cells look balanced but is that just the cells "resting" technically?
Yes the android app lets me change the numerical values of each setting see pic posted

I don't have and it didn't come with USB attachment but the Bluetooth hasn't given me complaints, except yesterday I was going over things and it kept locking the BMS but I found that if you enable charge and then discharge it unlocks....

I was thinking about an active balancer and also I read the part in Appendix C of the overkill BMS pdf and it has a method of top balancing when everything is still connected..

Thanks for the screenshots. The android bluetooth app looks very capable---at first glance it looks like a much cleaner interface than the iOS version we're using.

Your cell voltage look much better now. Noticed you had the Balance Turn-On Voltage set to 3.2v. We have this set to 3.4v. That's typically where cell voltages start to diverge enough to make balancing worthwhile.

I read your previous post where you discussed Overkill's recommended steps to balance the cells individually. Definitely a good option. For what it's worth, we've top-balanced our 4s 200ah pack a number of times. For some reason the cells will slowly drift out of balance after a month or two. Of course, we regularly do 100-10-100-10 SOC .5c - .6c discharges, which may be an aggravating factor. Anywho, got tired of doing these occasional top-balances (can't imagine the hassle of doing a 16s pack), so we installed the Heltec 4s 5a active balancer with a spst on/off switch. Whenever we notice the delta getting a tad high during the final stage of charging (cell voltages >3.4v), we turn on the Heltec. In approx. 2 hours all the cells are within 2-3mv of each other with a nominal voltage of ~3.6v (with 14.4v charge voltage). Works well for us.

 

[YahwehisKing]

Would you like me to say 13.69 years? if the batteries are rated for 5000 cycles and you cycle them once daily, do the math. If you cycle them less, do the math, more, do the math. ;p That's a lot to say every time you want to say it. Bottom line is it depends on individual usage, but at 5000 cycles based on one cycle per day, 10 is a fair number.

Yeah but if you're only cycling about 40% of your battery a day which is a lot in my case Ill use at most 10% a day, you'll get over 10000 cycles and at my use over 100,000 cycles. But even if you cycle every day 5000 times your battery's capacity will only drop 20-30% so a 15kw system will become 11-12kw.. I don't see much of a loss if my capacity doesn't drop much after 13yrs.... My SLA lost 30% after 1 yr being stored outside with temp swings and adding new batteries to old pack... But maybe I don't understand something about the cycle and discharge but as far as I can tell so far the point of logic offered is more of a sales point not a consumer reliability point....

 

[DerpsyDoodler]

Yeah but if you're only cycling about 40% of your battery a day which is a lot in my case Ill use at most 10% a day, you'll get over 10000 cycles and at my use over 100,000 cycles. But even if you cycle every day 5000 times your battery's capacity will only drop 20-30% so a 15kw system will become 11-12kw.. I don't see much of a loss if my capacity doesn't drop much after 13yrs.... My SLA lost 30% after 1 yr being stored outside with temp swings and adding new batteries to old pack... But maybe I don't understand something about the cycle and discharge but as far as I can tell so far the point of logic offered is more of a sales point not a consumer reliability point....

It is not a sales point. It's a generalization. Like I said, individual use will vary.

That said, I suppose I could further qualify it by saying, after those 5k cycles, the degradation is rated down to ~80% of original capacity, and you can still safely use them.

Also, the numbers I'm talking about are directed towards LFP, not SLA.

 

[YahwehisKing]

It is not a sales point. It's a generalization. Like I said, individual use will vary.

That said, I suppose I could further qualify it by saying, after those 5k cycles, the degradation is rated down to ~80% of original capacity, and you can still safely use them.

Also, the numbers I'm talking about are directed towards LFP, not SLA.

Are there any batteries out there expected to be used to 100% daily ? Possible yes but expected and depended on to ? I don't see the point of that. All advice is to get a larger bank in that case. Down to 80% though with that kind of use after 13yrs is crazy good compared to SLA which for me degraded 30% in the first year and you can still safely use them that's friggin good. All I'm saying is for me that means my investment is good for a lot longer that 10yrs at least 30yrs if we don't get some crazy solar storms lol

 

[YahwehisKing]

Thanks for the screenshots. The android bluetooth app looks very capable---at first glance it looks like a much cleaner interface than the iOS version we're using.

Your cell voltage look much better now. Noticed you had the Balance Turn-On Voltage set to 3.2v. We have this set to 3.4v. That's typically where cell voltages start to diverge enough to make balancing worthwhile.

I read your previous post where you discussed Overkill's recommended steps to balance the cells individually. Definitely a good option. For what it's worth, we've top-balanced our 4s 200ah pack a number of times. For some reason the cells will slowly drift out of balance after a month or two. Of course, we regularly do 100-10-100-10 SOC .5c - .6c discharges, which may be an aggravating factor. Anywho, got tired of doing these occasional top-balances (can't imagine the hassle of doing a 16s pack), so we installed the Heltec 4s 5a active balancer with a spst on/off switch. Whenever we notice the delta getting a tad high during the final stage of charging (cell voltages >3.4v), we turn on the Heltec. In approx. 2 hours all the cells are within 2-3mv of each other with a nominal voltage of ~3.6v (with 14.4v charge voltage). Works well for us.

Yeah the app is quite detailed I've come across posts that day the older version gives even more control just not as pretty.

Yeah the voltage seems to have regulated just need this snow to go away so a good inrush of charge comes in and I can see wether cell 15 goes higher than the rest. I think what's going on is more a resting voltage if I understand things right.

As for the settings that's the lfp normal default settings if 3.4 is a better setting to have it at I'll switch it.

Looks like I'm ordering a balancer today lol thankyou for the advice