AndyH said:
Disconnect from the pack and run thru the tests to make sure each individual channel is working correctly. The channels must work before the control section will work.
Sure, maybe its time to retest all of the cells. I've tested it before, but since then the board has been through a lot. Your instructions are concise and easy to follow so thank you for reiterating them. I read another forum posting that you had commented on a lot and It helped when I was testing the board earlier.
To my defenses with this, I have a lot of variables going against me and some very strange behavior from everything. My cells act weird, my variable transformer (what I've been trying to use to test) acts weird, my charger acts weird, and of course the bms acts weird. I don't have a single constant to go by to trouble shoot and so many times I have gone on a wild goose chase. Sometimes I was going in the right direction but didn't even now it and thought it was a wild goose chase.
To make my point, I just charged 8 cells in the first 8 channels of the board using my variable transformer set to around 30 V. As far as I know, everything went as expected. The leds started coming on as the cells reached around 3.5 and then were bright and stayed on as the cells stayed at 3.6 V. Each of the leds came on and then then when most of the cells were at 3.6, I needed to turn the power to about 33v on the transformer and then the green led came on fully. The cells were very close to each other and have now settled at about 3.47 V. Everything was silent, no strange humming or buzzing sounds from the transformer or the cells or the BMS.I tested the cells as they were charging and each cell was steadily growing in voltage. I thought it was perfect, or at least as close to perfect that I have ever seen.
The same day, after not even touching the bms, I try charging another set of 8. this time though one led came on and then the rest started to flick on making a "tut" sound every time. There was a humming sound from the transformer and a buzzing sound coming from the batteries I think. The heat sink of the bridge rectifier was hot so I turned the whole thing off. I replaced the lead wire from the bridges output and the wire connecting some of the cells to a thicker gauge, thinking maybe there was a lot of resistance. I don't know why this would matter when It had just charged another pack just a little while ago.
So I don't know why this pack didn't work. Now maybe this is it. the cells in the other pack were fairly close to each other in voltage. In fact only two cell were from another pack so those were the ones I soldered on with a wire but all the cells were fairly close to the others in voltage. Now this second pack is a bit less closely matched in voltage and is made from 3 different packs using good cells from each. I used 14 gauge copper wire to connect groups of cells to make my 8 pack.
Does the difference in voltage really make that big of a difference in the behavior of it charging. I thought I could use the bms to balance them.
Secondly, would mixing cells that still have their original connections ( the coated tabs) with cells that I solder wire to make connections be bad because of the difference in resistance? for example: I have two cells still attached to each other (positive to negative) and I have 4 of these pairs that I put together to make my 8 pack. would this mess the bms up?
sorry, this will be a bit longer I have some questions
You mention that it should start to glow at 3.62 but my cells never get to that voltage they start at 3.5 and are fully lit at 3.6 v. They usually stay at 3.6 and then after I unplug the charger they settle to a lower value. My cells are from used packs so I don't know if thats the reason the drop down lower.
Right now the bms is still a bit messed up. I had to replace the leds in channel 23 and 24 but I'm not using leds with a 2.0 forward voltage. thats why I was only charging 8 at a time.
as far as the cells being off in voltage, since I don't have a single cell charger, could I use my variable transformer set to about 4 V to charge one cell and just monitor it with a multimeter to make sure it doesn't go over 3.7? I did that to some other cells and then they started to charge really fast once they were at a higher voltage and then they dropped voltage after I had stopped charging them to where they were before (around 3.3 V) so I figured these cells were no longer holding a charge and I must have messed them up doing something else.
I also somehow melted one of the dewalt 8 pack cases today. I plugged something in and then suddenly a spark and then fire... I blew the fire out and the cells seemed unharmed (amazingly) but the case is ruined and now I only have two 8 pack dewalt cases instead of 3 so I can't do 24 s cells unless I come up with another way to connect all those wires to the cells without have to solder each individual one since these configurations are only temporary until I get all the cells balanced.
I wish I could talk to someone for just one day. One day were I tell them whats going on, they tell me a test and I do it and tell them the results and then they tell me how to fix it then I do that and tell them whats still wrong so they could tell me something else to fix or check. I've been trying to get this thing fixed for 2 weeks now and thats just for how long I have had this board posted. I've been trying to get all this stuff working for months.
The reason why time is so pressing, and I am so bugged out about this still not working is that this is for my senior thesis. I need to be done and have a working motorcycle by early April or I'm going to fail, as that was my proposed project. I had been looking into this for a year and this bms looked like the best option budget wise, it also doesn't have the amp limits that others have. I have a lot more to do, and If your interested you could go
here to read about my proposed thesis (though a bit has changed from that first post) and how its maybe different from others.
sorry this post was long.
If you had the time to read all of it, I thank you. I know there are many points and questions in this please try to answer any if you know about them.
thanks
Greg
Or recrimp them yourself across the holder. I'm not stingy with the alcohol, either, and tend to basically wash the board in it from top to bottom, usually in some type of container to catch the drippings. 
