Serious strangeness from 36v EVC Headway pack.

The BMS in those packs are garbage, it probably drained that cell and will do it again. I know from experience. I can offer you a Signalab BMS at a discount as you are a customer of mine. You can let people know if it works for you and warn people not use the stock BMS. The Headway cells are LiFePO4.

Thanks Terry. PM sent.

Hey, stud: Since misery loves company - let me just tell you that I've got the exact same headway pack as yours. Mine is in pieces on the workbench. One cell that was acting weird like you are experiencing (number 7 cell counting from pack minus), then I tried putting my bulk charger on the pack to fix it and totally blew out a different cell (forget exactly which one). And this AFTER replacing the stock BMS with a Signalab BMS from Ping. The pack is pretty easy to take apart, at least. I just pried the tabs off each end of the suspect cells with a screwdriver - very carefully! Did not get electrocuted - yet 8) .

You are correct, EVComponents is no more - a lot of guys paid them money and didn't even get their orders filled or their money back. So, we got crap packs, but at least we got something.....maybe a $500 bike rack.

I ordered three replacement cells from http://www.evassemble.com (close to $90 with shipping), but have not received them yet or heard of my order status..... ES member The Journey Guy has used this outfit with success.

Good Luck! I'm watching this thread like a hawk.

Mike

mikeross said:

I ordered three replacement cells from http://www.evassemble.com (close to $90 with shipping), but have not received them yet or heard of my order status..... ES member The Journey Guy has used this outfit with success.

Good Luck! I'm watching this thread like a hawk.

Mike

Click to expand...

If you follow my Headway thread, you'll have read that I just yesterday got another large shipment from Michael. I've told him more than once that we, as customers, would really like to see an updated status on our order page. He says he's working on it, but has other irons in the fire first.

I have found that my orders , from date of pay, to date of arrival, take about 10-12 days. How long has it been since you made payment?

TJG

mikeross said:

I ordered three replacement cells from http://www.evassemble.com (close to $90 with shipping)
Mike

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I'd also like to take this moment to point out to the members who have read my thread in the For Sale- New section, where I am offering fresh Headway cells, that perhaps now they won't think my price too far out in left field. My cells are here, they ship fast, and no worrying or waiting to hope they arrive at your home.

Now, back to our regularly scheduled program.

TJG

mikeross said:

Hey, stud: Since misery loves company - let me just tell you that I've got the exact same headway pack as yours. Mine is in pieces on the workbench. One cell that was acting weird like you are experiencing (number 7 cell counting from pack minus), then I tried putting my bulk charger on the pack to fix it and totally blew out a different cell (forget exactly which one). And this AFTER replacing the stock BMS with a Signalab BMS from Ping. The pack is pretty easy to take apart, at least. I just pried the tabs off each end of the suspect cells with a screwdriver - very carefully! Did not get electrocuted - yet 8) .

You are correct, EVComponents is no more - a lot of guys paid them money and didn't even get their orders filled or their money back. So, we got crap packs, but at least we got something.....maybe a $500 bike rack.

I ordered three replacement cells from http://www.evassemble.com (close to $90 with shipping), but have not received them yet or heard of my order status..... ES member The Journey Guy has used this outfit with success.

Good Luck! I'm watching this thread like a hawk.

Mike

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Yeah Mike, I hear ya. I've been watching your thread too.

dnmun said:

if you can get a single cell charger and charge up the low cell, you may be able to see if it will hold a charge. i see that the voltfreaks are on sale now too. tony tieger just ran an ad today.

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Who/where is "Tony Tieger"?

See my latest battery post here:

http://endless-sphere.com/forums/viewtopic.php?f=6&t=19201

The following instruction refer to the Signalab BMS and generally holds true for most of them.

First of all, the +plus lead does not go to the BMS at all. This only controls the minus, or negative lead.
The three connections are as follows:
B- = minus lead from battery pack.
P- = Negative output lead going to load/controller.
C- = negative input from charger.

The long white connector with the small wires is for connecting to the individual cells. Starting first with the
red wire, connect this to the plus output of the pack. Connect the rest of the wires in sequential order, to
the positive of each cell (between each pair of serially connected cells).

After connecting the wires, verify the correct order by measuring each pin on the connector (not connected to
BMS) with respect to GND (Bat-). Starting at the black wire, you should read +3.3V, next +6.6V, and down
the line adding about 3.3V per pin. The exact voltage will depend on the charge of each cell.

Note that ground (on the last cell) is already connected to the BMS board through the main ground line, so
there is no need to connect a small wire there. This allows the use of a connector with an even number of
pins and is pretty standard.

Notes:
The plus lead from the pack goes directly to load, or through an optional external fuse, then to the load.
The positive input from the charger goes directly to the positive terminal of the pack.

Theory of operation
There are voltage monitors for minimum voltage and max voltage. If any cell reaches the minimum voltage,
the output mosfets will shut off. If any cell reaches the max voltage, the mosfet on the charger input will
shut off. The board also has a max current detector. Looking at the board, you see a row of power mosfets.
Next to the tabs, is the connection point for the output (P-). Next to this you will see the shunts (usually 5)
that detect current. On the other side of the shunts is where you connect the battery pack.
For currents up to 15A, air flow is not required depending on ambient temp. Currents greater that that may
require airflow. Currents above 30A will definitely require air flow or damage to BMS will result.

Okay, I got the from Terry this week and put in the first one this evening. Everything seems to be going well. I will leave it on the charger overnight and hopefully be able to take it for a test run sometime this weekend. Will keep everyone posted. Also, I need to purchase a single Headway 10ah tabbed cell. Anyone have a suggestion for where I can get one quick and/or cheap?

it may not catch up with your other cells right away after you put it on the charger so only use short discharges until that cell matches the others. this is how they die, singly and exhausted while all the other cells are pulling their heart out. do not expect any BMS will prevent the cell from dropping below 2V. it should but sometimes they don't.

Well I got the first of the Signalab BMS' installed in one of the packs this week and took it for a good hard ride with no issues at all. The real test comes when I give it to the customer that has a much larger hill than I have and has more load on the bike than I do. Will keep you posted. The actual BMS swap was very simple though and the instructions that Terry sent with them was more than adequate.

Does the Signalab bms fit inside of these packs? Nice neat and tidy?

The Signalab that Terry sent me(which I believe is the V3) is much smaller than the Headway so it doesn't work very well in the original spot. I think I took some pics of where I put it and when I get home I will post them up, but basically I put it in the very back of the case in between the plastic and the key switch. It is a pretty tight fit, and if it was drawing more amps than what the Amped gear motor does I might get worried about heat, but so far so good.

Edited to add picture.

View attachment bms.JPG

Hey, Stud: Nice work on the BMS replacement! Those directions from HTB_Terry for wiring the BMS are really good. You had asked about getting some tabbed Headway cells. I am *trying* to get some through evassemble.com but it has not been real smooth so far, and, with shipping they are just under $30 ea. ES member The Journey Guy has been REALLY helpful in dealing with EV Assemble. They aren't crooks, but you better not be in a big hurry, either, I think they just don't quite have it together yet. Long story short, my June 11th order arrived yesterday, but with screw type cells, not the tabbed cells I ordered....

My headway pack is currently a 10s (two bad cells removed, large wire soldered in place of the bad cells for now), and I have been riding it to 4ah discharge, then charging it back up with a single cell charger - which takes forever! However, the pack is beginning to settle down and stays balanced. My Ping BMS has been removed, but once the replacement cells are installed and babied, I'm going to put it back in and try for bulk charging of the pack. Ypedal wrote that he discharges new lithium packs to 30%, then recharges and balances them - repeats this 3 times. All this before he uses the pack. My first discharge of my Headway pack was to 70%, which I thought was pretty conservative at the time. Now, I'm thinking that was too much for these Headway packs to handle when new. Also, a couple of my cells seem to take much longer to charge than the rest (should keep some data, but they do finally charge up). This could be a problem when bulk charging.

Since we're pretty much having the same experience with our packs, I'm thinking your packs will be fine - just watch them like a hawk for the first few charge/discharge cycles. And, if the BMS trips - don't blame the BMS (a mistake I made)!

Mike

mikeross said:

Since we're pretty much having the same experience with our packs, I'm thinking your packs will be fine - just watch them like a hawk for the first few charge/discharge cycles. And, if the BMS trips - don't blame the BMS (a mistake I made)!

Mike

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I was following you until this last statement. What do you mean by if the BMS trips don't blame the BMS. If all the cells are balanced and have been cycled a few times and the BMS is tripping what should I be blaming it on?

PM sent. In my experience there WAS a bad/low cell. Even though I thought it was all charged up and balanced. One cell was low already, with less than 2ah used from the pack. So, the BMS was correct in shutting down the pack, I just couldn't believe it. Be careful to check the individual cells if the BMS trips. I'm beginning to think it's some sort of charging issue where one or more cells don't charge as fully as the rest, then one of these cells hits LVC real quick. Hope that explains it a bit better??

Mike

You can install the Signalab BMS in the original location. It is shorter than the other board, so you just have to secure one end with some silicone glue or something.

If you have one of these packs, you should charge each cell at 3.65V and leave it on until the current is very low, about 50mA. They have an unusual charge slope where the final part of the charge from 3.3V to 3.65 takes hours. Once each cell is fully charged, the BMS should keep it balanced. It is highly recommended to do 5 to 10 cycles of 1 to 2 AH (1 to 2 miles) with overnight charging (2A max) between cycles. This "breaks in" the cells and makes it easier to balance.

There is a chance that the original BMS has a defect that will allow one cell to drain. I suspect this from anecdotal evidence. To be safe, if you purchase one of these packs, immediately pull off the white balancing connector.

HTB_Terry said:

...If you have one of these packs, you should charge each cell at 3.65V and leave it on until the current is very low, about 50mA. They have an unusual charge slope where the final part of the charge from 3.3V to 3.65 takes hours. .... It is highly recommended to do 5 to 10 cycles of 1 to 2 AH (1 to 2 miles) with overnight charging (2A max) between cycles. This "breaks in" the cells and makes it easier to balance....

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It sure is reassuring when once in a while I read someone's post (like yours) that so closely matches my initial observations when I was maticulously experimenting with new my Headway cells. I also discovered that using 3.8 volts for breaking them in substantially speeded up and increased the thoroughness of the the break in process. And after several cycles at that higher voltage with very low current levels like you describe (even less amps actually), I am now able to have them retain that surface charge (3.4-3.6v) that some folks talk about for several days. Now that all of my cells are nicely broken in that way, I have gone back down to 3.6-3.7 volts for routine balance charging and all is good.

Yes, unusual charge slope is right!! I too have been doing extensive bench testing for both charge and discharge curves.

To tell the truth, these Headways don't really have a 'curve', it's more like a cliff!! According to the data collected via CellLog 8s and analysed via Log View, I have to totally agree with the above poster. For hours these cells charge along a straight line, and then all the sudden within 1 or 2 minutes, they 'climb the cliff' and go straight up to their top charge.

The more I use them, the more I like them! They have a unique personality, but once you get to know them, they'll probably be friends for life!

TJG

Just wanted to update this thread. The Signalab BMS from Terry is holding up well in the one pack that I switched out the Headway BMS in. So that has been a huge relief on that part and I want to thank Terry for coming through on that for me. The BMS is a very easy swap and anyone with basic soldering skills should be able to swap them out easily. Because of the one completely dead cell in one of the packs I ended up using my personal pack for one of the builds so I currently have no battery. I am needing one single tabbed Headway 10ah cell. I just looked at Evassemble and it is $17 for the cell and $32.50 for shipping :? which seems a bit extreme to me. For any of you that have dealt with evassemble, do you think it is worth it to try and get them to lower their shipping charge or are they firm in their shipping charges? If anyone has a single tabbed Headway they are willing to sell, I am an interested buyer.

StudEbiker said:

I just looked at Evassemble and it is $17 for the cell and $32.50 for shipping :? which seems a bit extreme to me. For any of you that have dealt with evassemble, do you think it is worth it to try...

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I have to be honest with you, in that Michael from EV Assemble has become a questionable sales agent. Another member of the forum has been trying to get delivery of 3 tabbed cells for over 45 days now, and he asked me to get involved because I have dealt with them in the past to get my Headways.

Back then, they were nothing but eager to please, however nowdays it seems as if things have changed.

So, at this point, I personally would not do business with them. Matter of fact, there is a Paypal claim against them at this time, and hopefully it won't have to go the full distance. But until it's resolved, I would look for Headways elsewhere. I most probably will not do business with that company any more. I was waiting a few days to make an addition to the 'Manufactures to avoid' thread in order to see how it all worked out, but since you asked, I thought I'd save you some lost $. :wink:

TJG

Thanks for the heads up...... it's starting to look like I'm not going to get to do much riding this summer.

I recall someone posting up a link to another washington state firm recently (last weak or two), but i could not find it again for you. When I checked it out it appears to be linked to David Kois previously associated with EVC. I think he was one of the good guys, but then I pretty much avoided all of the hoopla over EVC. And I don't recall exactly what they were offering as far as the each cell type, except that they had the 12 ah screw terminal types (that's what I was searching for at the time) edit: oops I think he had the 16 ah ones, not the 12ah ones

Also there is BMS battery. I know of one fella who doesn't participate here in the ES forum that had a good encounter with them. Chances are I will go with them on my next purchase. I think they have the cells without the screw terminals: http://www.bmsbattery.com/index.php?main_page=product_info&cPath=1_10_11&products_id=10

The Journey Guy said:

StudEbiker said:

I just looked at Evassemble and it is $17 for the cell and $32.50 for shipping :? which seems a bit extreme to me. For any of you that have dealt with evassemble, do you think it is worth it to try...

Click to expand...

I have to be honest with you, in that Michael from EV Assemble has become a questionable sales agent. Another member of the forum has been trying to get delivery of 3 tabbed cells for over 45 days now, and he asked me to get involved because I have dealt with them in the past to get my Headways.

Back then, they were nothing but eager to please, however nowdays it seems as if things have changed.

So, at this point, I personally would not do business with them. Matter of fact, there is a Paypal claim against them at this time, and hopefully it won't have to go the full distance. But until it's resolved, I would look for Headways elsewhere. I most probably will not do business with that company any more. I was waiting a few days to make an addition to the 'Manufactures to avoid' thread in order to see how it all worked out, but since you asked, I thought I'd save you some lost $. :wink:

TJG

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Hello TJG,
This is Michael from EV ASSEMBLE. If this happen in next time. We will take our responsibility to solve the issue as this time and provide a 15% return to the customer. Just make sure to be trusted!
By the way, welcome to discuss in this thread.
http://endless-sphere.com/forums/viewtopic.php?f=14&t=20046

As right now we have large stock, we are very confident that we can provide cells very fast.