Lessss
1 MW
hmm... I'm getting 54 v at the charge port and dicharge port, but voltage drops to 6v when I plug it into the bike. Time to quadruple check the wiring and connections before bypassing the bms.
Headway Pack Builders thread
- Thread starter frodus
- Start date
dnmun
1 PW
haven't decided exactly how i will make the connections in series. i have some lugs, but may make and solder wire loops on end of the 12G solid wire connector, and attach the sense wire at the same time. it will take a few days to set up so i will look into it.
oatnet
1 MW
dnmun said:
falcon EV's LiFe came with solid copper wire loop connectors in '07, but we found they had a very small contact patches and high resistance. I would recommend the lugs or copper strap.
-JD
Lessss
1 MW
Swapped my BMS out and pack works. Looks like I got 1 outta 2 BMS as DOA.
dnmun
1 PW
you have a bad ping signalab BMS?
or is this a cammycc BMS? do you have pictures of the BMSs that you have?
or is this a cammycc BMS? do you have pictures of the BMSs that you have?
Lessss
1 MW
From Kenalten.com (Headway) They are sending a replacement.
Just wanted to throw some pics up here to show my build. Still working out the kinks, have had a few failures, chocked up mostly to loose wiring, still working on a proper balance. Following Jules' lead I found some cheap cutting boards at the 99cents store and drilled out my spacers. The major difference being that i just drilled for the top portion that rises out of the cell. This offers just another barrier between terminal and the positive outer ring (although still taped up my interconnects, and i love the headway condom idea using innertube someone started in another thread). I am cutting together a How-to video of my build hope to get it up here soon.
frodus
10 kW
From what KAE said, the BMS he sells is not headway, and look nothing like the headway we got, so they're something else.Lessss said:
Lessss
1 MW
Ah sorry I assumed they were. Even though headway bms aren't even really headway. With any electronics there will be a percentage of failures, all I care is I get a working replacement.
Hi:
Just finished the mechanical build on my 48V 10AH pack. I "borrowed" ideas from throughout this thread. Here are some details:
1) Case: Home Depot 16" tool box. Fits the cells perfectly as you can see. Cost $5.97.
2) Wood: scrap left over from other projects. The side pieces are 1/4" chip board (mistake ... should have used good quality plywood). Cost: $0
3) Inter-cell connectors. Unfortunately Home Depot does not carry solid copper so these are copper plated. Cost $1.24 for 12
Below are some photos. I will add some more in the next day or 2.
I have the unit all wired up and connected to my bike (9 continents from Justin at ebikes.ca). I checked the voltage of each of the cells (all 3.31 or 3.32V) and the overall voltage (53.1V). So far, so good. I double checked all my wiring before connecting to the bikes controller.
Turned on the controller .... quick flash on the CA and nothing! I checked the voltage with the controller on and it was way down (couple of volts). So, I assumed I needed to charge the units as the cells are shipped without any charge (is this correct?)
I have no LifePo charger right now so I used a cheap (Ebay) SLA 48V charger. As soon as I plugged the charger in the CA turned on and showed 58.8V. So far, so good.
BUT: after about 1 or 2 minutes, my charger shut down (like the battery it was charging was fully charged). CA stayed on but showed 54.X Volts.
If I unplug the charger, the voltage drops to a few volts and the CA shuts off.
I'm ordering a LifePo charger and expect to get it later this week.
Is my problem that the batteries are just not charged?
Or is there something more serious?
Any thoughts welcome.
Thanks.
Just finished the mechanical build on my 48V 10AH pack. I "borrowed" ideas from throughout this thread. Here are some details:
1) Case: Home Depot 16" tool box. Fits the cells perfectly as you can see. Cost $5.97.
2) Wood: scrap left over from other projects. The side pieces are 1/4" chip board (mistake ... should have used good quality plywood). Cost: $0
3) Inter-cell connectors. Unfortunately Home Depot does not carry solid copper so these are copper plated. Cost $1.24 for 12
Below are some photos. I will add some more in the next day or 2.
I have the unit all wired up and connected to my bike (9 continents from Justin at ebikes.ca). I checked the voltage of each of the cells (all 3.31 or 3.32V) and the overall voltage (53.1V). So far, so good. I double checked all my wiring before connecting to the bikes controller.
Turned on the controller .... quick flash on the CA and nothing! I checked the voltage with the controller on and it was way down (couple of volts). So, I assumed I needed to charge the units as the cells are shipped without any charge (is this correct?)
I have no LifePo charger right now so I used a cheap (Ebay) SLA 48V charger. As soon as I plugged the charger in the CA turned on and showed 58.8V. So far, so good.
BUT: after about 1 or 2 minutes, my charger shut down (like the battery it was charging was fully charged). CA stayed on but showed 54.X Volts.
If I unplug the charger, the voltage drops to a few volts and the CA shuts off.
I'm ordering a LifePo charger and expect to get it later this week.
Is my problem that the batteries are just not charged?
Or is there something more serious?
Any thoughts welcome.
Thanks.
Attachments
frodus said:
Travis:
I was part of your May group buy (just got around to building my pack this weekend). Just built my pack and having a problem similar to Lessss' problem (54V ... then a few Volts when I connect it to my bike). If the BMS turns out to be the problem, how can I get a replacement?
Also, I had one cell that checked in at 2.2Volts (I'm not using this battery in my pack ... it was an extra). Any practical way to get a replacement for this one?
Any info would be very helpful.
Thanks,
Preston
dak664
1 kW
- Joined
- Aug 17, 2008
- Messages
- 317
It's not clear from your pictures where the medium black wire from the BMS is connected (not the really small black sense wire which goes to battery minus). I use that medium wire as the charger minus input, with charger plus going to physical battery plus.
Did you put a voltmeter on the header pins and verify the voltage goes up by 3.3 as you buzz up the row? I like to clip the voltmeter minus to the physical battery terminal and use a sharp voltmeter plus probe on the header, less chance of shorting two pins that way.
Did you put a voltmeter on the header pins and verify the voltage goes up by 3.3 as you buzz up the row? I like to clip the voltmeter minus to the physical battery terminal and use a sharp voltmeter plus probe on the header, less chance of shorting two pins that way.
dnmun
1 PW
pvorlicek said:
did you charge up the cell that was 2.2V? why should they replace it? why should they replace the BMS? can you figure out that it is broken? i doubt if any of them are bad since they were just tested on the assembly line. to say they are broken out of the box is stretching it imo.
dak664 said:
There are 5 black wires coming from the BMS: 2 heavy guage from the B- side and 2 heavy guage plus one "medium wire" from the other side of the BMS. I am NOT using the medium wire to go to the charger .... I am using one of the heavy guage wires to go to the charger.
I will "buzz up" the row as you suggest. If they do not go up by 3.3 ... AND the individual cells were checked before installation (all at 3.31 or 3.32) .... AND the overall voltage of the pack (measured before going to the BMS) was good .... wold this indicate a BMS problem?
Thanks
did you charge up the cell that was 2.2V? why should they replace it? why should they replace the BMS? can you figure out that it is broken? i doubt if any of them are bad since they were just tested on the assembly line. to say they are broken out of the box is stretching it imo.
I purchased 24 batteries. 23 tested either 3.31V or 3.32V. What could cause one battery to be 2.2V? Did it just "degrade" while crossing the ocean? What is your plausible theory?
On the BMS ... let me get this straight: this thing comes with absolutely no documentation, in a plain white box (no markings) ... not sure if there are any real markings on the item itself ... and you want me to believe this thing was FULLY tested before shipment. Sorry, I've been in the electronics business for some time and this has all the "markings" (no pun intended) of a poor quality operation. No respectable QA persion would allow anything to be shipped out like that. I suspect they did some limited basic test.
Now don't get me wrong ... I knew this is what I was getting into .... AND also not that I did not say the BMS was not working .... I asked Travis if there was any recourse IF the BMS was not working.
I'm ready to try to get this thing tested to confirm it's state ... but I did notice my symptoms were similar to Lessss' ... and he solved his problem by swapping BMS'
I purchased 24 batteries. 23 tested either 3.31V or 3.32V. What could cause one battery to be 2.2V? Did it just "degrade" while crossing the ocean? What is your plausible theory?
On the BMS ... let me get this straight: this thing comes with absolutely no documentation, in a plain white box (no markings) ... not sure if there are any real markings on the item itself ... and you want me to believe this thing was FULLY tested before shipment. Sorry, I've been in the electronics business for some time and this has all the "markings" (no pun intended) of a poor quality operation. No respectable QA persion would allow anything to be shipped out like that. I suspect they did some limited basic test.
Now don't get me wrong ... I knew this is what I was getting into .... AND also not that I did not say the BMS was not working .... I asked Travis if there was any recourse IF the BMS was not working.
I'm ready to try to get this thing tested to confirm it's state ... but I did notice my symptoms were similar to Lessss' ... and he solved his problem by swapping BMS'
dak664
1 kW
- Joined
- Aug 17, 2008
- Messages
- 317
Well I think that is wrong. The heavy wires are doubled on each side for extra current, one pair is to pack minus out and one pair to battery minus in/out. The medium black, on the same side as pack minus out, should be charger minus input. At least that is what is working for me.pvorlicek said:
dak664 said:You got a BOX! I am jealouspvorlicek said:. Both of my 12 cell BMSs from the group buy were in pink bubble wrap bags, and are working.
There are markings on mine for the black wires, but they are covered up by the white RTV.
Maybe I was dreaming about the box ...
Documentation ... who needs stinking documentation ... I don't need no stinking documentation!
After all, this is "plug and play" .... right?
I actually have 3 ebikes .... one for myself, one for my wife and 1 spare. It's not just a job, its an adventure!
dnmun
1 PW
if you don't have single cell charger to charge up the low cell then just jumper it to another cell and it will charge up.
all batteries self discharge.
i beg to differ since we just went over this in patrickzas thread. i consider the headway BMS to be exceptional quality, tuned to about .1% precision in the balancing, overbuilt to the max in terms of charging FETs and the output FETs which are all 4310s which even my controller does not have. then they put a massive heatsink on the entire structure and added cables capable of carrying over 100A of current with no degradation. i have analyzed about 6 chinese BMS designs, and use ping's BMS also, so i feel i know that they are the very best, and do not come out of the factory broken. period.
i already discussed the layout of the BMS circuits over there, not in detail, but enuff to satisfy me.
all batteries self discharge.
i beg to differ since we just went over this in patrickzas thread. i consider the headway BMS to be exceptional quality, tuned to about .1% precision in the balancing, overbuilt to the max in terms of charging FETs and the output FETs which are all 4310s which even my controller does not have. then they put a massive heatsink on the entire structure and added cables capable of carrying over 100A of current with no degradation. i have analyzed about 6 chinese BMS designs, and use ping's BMS also, so i feel i know that they are the very best, and do not come out of the factory broken. period.
i already discussed the layout of the BMS circuits over there, not in detail, but enuff to satisfy me.
Lessss
1 MW
Bubblewrap is NOT an anti-static material. I've seen entire computers arrive delivered to customers DOA(from ALL the big name manufacturers). Never under-estimate a minimum wage workers "frock it - ship it" attitude, especially if they get deducted pay for none functioning product coming off the line. I know my BMS was DOA cause I had two (3 actually as I also got a GG BMS cause I expected one of these 2 to fail). I swap one out for the other and one of the 2 works. Ergo 1 DOA.