Well I almost burnt the house down. Time to ask for some help....

Gazoo

Dumb Dumb
Yes, it takes a bit more time, but 3.4V means less risk during the long part of the top balance and will not degrade your cells as bad as trying to achieve 3.65V in one step, if you're not there to watch it.
It would have taken twice as long had I used the step method. I would like to see any data that indicates the amount of cell degradation difference using the step method and setting the PS to 3.65 volts.

The voltage drop between the PS and cells has not changed and by increasing the CV, and thus putting the PS back into CC / bulk mode, the 12A will create even more voltage drop. Also keep in mind that you don't want to run these small supplies at more than about 80% for continuous use.
I have a fairly good understanding regarding voltage drop. My Riden hums along nicely putting out the full 12 amps. I used it to parallel top balance my cells, to charge my cells several times after connected in series, and to charge my Valence batteries with the PS running at it's full output. Many others have used the traditional PS's running at their full output without burning them up. But setting those at 80% output is good advice.

Higher quality power supplies utilize a dedicated voltage sensing circuit, but these are significantly more expensive. We have a few small PS in our shop. One is a 5A linear (no v-sensing) and we use 6AWG wire on it to have an extremely low drop between the PS and cells. Most of our larger models, 60A etc., have built in voltage sensing making this sort of thing a non-issue..
I didn't want to spend a lot of money on a power supply for a one time use. I opted for the Riden due to it's many features including the charging feature. Granted it wasn't that cheap and I have no regrets buying it. As you said using a voltage sensing PS would be the safest way to parallel top balance. I trusted the charging feature of my Riden and slept while my cells were charging although I was awake to watch my cells reach their end of charge. I had tested the Riden on my Valence batteries before I parallel top balanced.

I know another member used 6AWG wire with his Riden and had the same issue I was having. His didn't put out the full amps until he adjusted his PS above 3.50 volts. Personally I used 12AWG cable.

I am not arguing against the step method and to each their own. My Riden went into CV mode when the cells reached 3.391 volts and it took another four hours to finish the charge. So the cells were not held at a high voltage for very long and if there was any degradation I doubt it could be measured even if it could be measured. :)
 

DeeEyeWhy

New Member
I don't know what happened or what to do now. Any help would be sooo appreciated.
Whats your setup. Controller, panels?
Are the settings on your CC(charge controller) correct for LiFePo4? It should be set to 13.5v or less. Even without a (highly recommended/required) BMS this shouldnt have happened so quickly. There are issues elsewhere in your system and we should pinpoint them before you continue.
 

Dave Knapp

New Member
ANYTHING resistive will drain the cell.
If you have a roll of heavy wire, you can connect CAREFULLY the spool directly to the high cell... for a few seconds at a time.
gotta have over 20’ of wire in the spool, not a short wire...
Well, I'm back again. With the old addage, There's no such thing as a stupid question, I feel ready to push that envelope. I have 2, 16s banks of 3.2v 150Ah Calb cells, I have 2 common port 48v, 16s, 150A Daly BMs units, one for each bank. The Daly instruction sheet is a little terse, so I thought it best to ask, rather than err. The instructions say, "Connect the thick blue wire(B-) to the battery pack total negative pole. Disconnect the wires for the batteries from the BMS side." I get this much. Then, it says "Connect the wires to batteries. Start from the thick black wire to total negative pole (B1-), then connect the 2nd red thin wire to the first battery positive pole (B1+)" I realize that these instructions were transliterated from Chinese, but it doesn't feel right. Do they mean the thin black wire in the harness? Is the 2nd red thin wire really the first red thin wire that is next to the thin black wire. And finally, which is the 1st battery? The one with the vacant + terminal or the one with the vacant - terminal? Sorry for the questions, but this is really the prelude to the serious stuff. Also, although it doesn't actually say it, I'm thinking that the BMS is in series with the battery bank and the charger, not in parallel. Help.
 

ken morgan

Solar Addict
woof... after going through this... an answer I can spit out in full confidence. First, before you wire up anything, order the "battery monitor light with switch" it allows you to turn on the Daly BMS with no other conditions met. (important if you hook it up via bluetooth or via the other cables. secondly. do not plug anything into the BMS until all connections are done. black wire goes to minus terminal of the pack. (in the end B- goes their as well... at the end). first red in line after the black wire goes to that cell's positive. each successive red wire goes to the next cell in line. so black to pack negative, 1st red to that same cells positive... next red to the positive of the next cell, etc. etc. etc. so if you are running 1p 16s s you indicate... then start with the 1st batch of cells and wire it black to negative, red to that cells positive and continue down the line until all of the cells are wired in. once you have this use a voltage tester to ensure that each cell is properly represented by checking voltage. it should go up in steps of (3.4 volts approximate) as you move to each adjacent cell... IE: you have the harness in you had, put your negative probe on the black. the first red wire next to the black should read 3.xx, next should read 7.xx next should read 11.xx etc etc etc. once you have checked that all cells go up the same amount you can now hook up the B-..to the minus of the pack...same as the black wire. ( DO NOT PLUG IN BALANCECABLES YET..) plug in all the rest of the connectors... then plug in the balance leads. ensure you already have the program loaded, open it once you plug in the balance leads, it might or might not turn on the Bluetooth dongle. if it does not push the button on the "battery monitor light with switch" anything less is a crap shoot as you might brick the unit or play with it for hours trying to get it to light off. that stupid little switch makes it fire right up, you can then click on the BT option for the BMS and all is well. everything else is a crap shoot of trying a million things that people on line have managed to get to work...many of them with no proof of documentation. I followed all the advice, mine fired up on the first time. then it went rouge and would not fire up.. I fought trying the various schemes and burned up an inverter charger (do to inrush current, or something. still under investigation) and the unit bricked. I ordered and got the little light dongle and that BMS fired up the first time I pushed the button. nothing else would work. its a cheap 10 USD. many sellers of the bms offer it for free depending upon order. GET IT. it will save you posting an identical post like mine, with everybody saying short this, short that.. blah blah blah. the switch works...its 10 bucks. and no massive sparks on a 48 volt system which you will get trying the various short this to that methods. (I honestly think this is what fried my inverter. I tried to use it to send power in charge mode and either the BMS or the inverter did not like that. I then tried the short and the inverter will no longer put out power when charging is selected. shitty documentation, but other than that the BMS seems sound.

R

Ken


 
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Dave Knapp

New Member
Ahh I love it when one of my drunk posts actually makes sense... good to see I did not curse too much this time as well.
20 years in the Navy - I can handle it. Thanks for the tutorial. 2 questioins. Please tell me more about the Battery Monitor light with switch. I'm in the Philippines and sourcing it will be challenging. The more info the better. Second, I don't have balancing cables. I've seen them in a video or 2, but am clueless as to how/why to use them. Thanks.
 

ken morgan

Solar Addict
20 years in the Navy - I can handle it. Thanks for the tutorial. 2 questioins. Please tell me more about the Battery Monitor light with switch. I'm in the Philippines and sourcing it will be challenging. The more info the better. Second, I don't have balancing cables. I've seen them in a video or 2, but am clueless as to how/why to use them. Thanks.
you can order via Alibaba or also from i think eBay or Amazon. I'll post a link. The balancing/sense cables come with the BMS. it is a plug (sometimes two depending upon model), that has one black wire and then a corresponding number of white (sometimes red) to the number of cells you are using in your battery bank. so if you are doing a 16s bank, or a 2p16s like I am, it will have 17 wires on one plug. (at least mine did) like I said some fo the models have two plugs

in the link below it is the little dongle with 4 light bars and a pushbutton.


link to daly accesories on ebay, might be others
 

Dave Knapp

New Member
you can order via Alibaba or also from i think eBay or Amazon. I'll post a link. The balancing/sense cables come with the BMS. it is a plug (sometimes two depending upon model), that has one black wire and then a corresponding number of white (sometimes red) to the number of cells you are using in your battery bank. so if you are doing a 16s bank, or a 2p16s like I am, it will have 17 wires on one plug. (at least mine did) like I said some fo the models have two plugs

in the link below it is the little dongle with 4 light bars and a pushbutton.


link to daly accesories on ebay, might be others
Thanks for doing this leg work. Really appreciate it. The Daly BMS I have states that it has passive balancing, and came without any balancing cables. Maybe nothing else needed? I'll look online for the Battery Monitor. Not on Alibaba, though. They sent the last thing I ordered by fedex, and fedex doesn't deliver here, telling me I had to drive 2 1/2 hours across the mountains to pick it up. . I told Alibaba, and their response was to keep waiting. I even sent them a screenshot of the text from Fedex. Duh. Turned it over to the credit card company. I'll try Amazon and Ebay.
 

Dave Knapp

New Member
Thanks for doing this leg work. Really appreciate it. The Daly BMS I have states that it has passive balancing, and came without any balancing cables. Maybe nothing else needed? I'll look online for the Battery Monitor. Not on Alibaba, though. They sent the last thing I ordered by fedex, and fedex doesn't deliver here, telling me I had to drive 2 1/2 hours across the mountains to pick it up. . I told Alibaba, and their response was to keep waiting. I even sent them a screenshot of the text from Fedex. Duh. Turned it over to the credit card company. I'll try Amazon and Ebay.
Followed your link. Thanks. Shipped direct to Philippines, but looks a little slow. Aug 31. We'll keep our fingers crossed for a better schedule. I buy a lot of stuff from China. Sometimes it's only 10 days. Thanks again. I'll holler at ya when it comes in. Nothing to do now but have a beer and wait. Be safe.
 

Dave Knapp

New Member
Dave take a photo of all the wireing your BMS came with and post it here.
The BMS says it's common port with balance. Shown are battery leads, temp sensor, and Bluetooth dongle. There is 1 vacant connector labeled Light Board.
 

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ken morgan

Solar Addict
The BMS says it's common port with balance. Shown are battery leads, temp sensor, and Bluetooth dongle. There is 1 vacant connector labeled Light Board.
the leads sticking out of the bottom (by your photo) are the balance/sense leads. this is a difference in terminology issue. you have the balance leads, they are the same as the sense leads or what you termed battery leads. no worries, this is the result of piss poor translation of the Chinese sellers. that lead is the one you hook up according to my instructions. one end is black... the rest are red. black goes to the minus of the battery. the positives go in line to the individual cells in order. look at any of wills videos in regards to this on you tube he walks you through this on his videos. you just need the light board to get a guarantee of BMS starting. which is/was where my issues lie. the light board makes it turn on right away with no issues.. now for the hard part... that a Marine figured this out ahead of a squid is sad.. I am the one who supposedly eats crayons for a living. Good luck Bro and Semper Fi! :) :) :) PS we are on the same time frame so Message me anytime you have a question.. no guarantee that I can answer it but i will try. And bump all you non military folks who take offense to a little teasing... its a part of our nature :) Dave will get over it and probably start a new thread to f+++ with me... its all good.
 
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