Headway 48v 10ah - EVcomponents.com

[Russell]

I would say the fact that the BMS supplied with the pack didn't come close to the advertised current rating is cause for concern as was the spotty way the pack was glued down inside the box. I haven't followed the full thread but I would hope that info got back to the supplier and manufacturer.

-R

 

[Lock]

I believe you can rest assured

 

[velowatt]

I have dine some "break in" rides on 48V 10Ah Headway+BMS from EV components (a few rides of 10 mi using 2-2.5Ah each). The Headway BMS did cut out a couple of times wile riding, usually after hitting a bump, requiring that I reset the BMS by switching off and then back on. My controller ("35A") only actually pulls a max of about 32A, so I was curious as why this would trip the BMS in this way.

Curious, I took the pack out, wondering if the BMS or some other component was rattling around and causing a short circuit or bad connection. The BMS came attached to the Headway pack with cellophane tape, which had become loose. There is a beefy heatsink on the board, one corner of which has been partly melted!

I mounted the battery pack in its big black box, but on its side to fit better in the rear trunk I am using. The top of the box adds 1 inch to the height of the box, and is heavy, so I discarded it, and mounted some 1/4" bolts on the side of the box to use a (+) and (-) terminals. The positive post was close enoughh to the BMS that when it hit a bump, the heatsink contacted and tried to weld itself to the terminal. Must have been some big sparks in the box. Fortunately, the BMS shut down the pack before a meltdown occurred.

Sooo, now the BMS is bolted to the plastic cell holders with an insulated metal strap and the positive terminal moved to a safe location, and everything seems to work great. I now have fuses on both battery discharge wires as well. The BMS appears to have protected both the battery and itself. Prolly a good safety feature to have. Also good to pay attention to where you locate exposed metal parts that carry power, Doh!

 

[dogman dan]

With my pingbattery, Ive had cut outs when I sealed the thing up in an airtight insulated bag. I think the bms sealed in a pastic box is not the way to go unless it is connected somehow to an external heat sink. I think the bms has gotta breathe unless it is really cold out.

In my opinion EV components got taken to task pretty thoroughly for this bms issue with the pack being reviwed. What are you looking for speedfreak? Should he rant about the vendor or just say the item has a problem? Is this a vendor review or just a review of the product?

 

[Speedfreke]

hi dog, 9 pages of reading, maybe I missed something. It was interesting reading though. What I read was a seamless battery testing review but in fact there was a break which didn't get full address . I got a private message from a member quote: "ypedal got ripped-off and let EVC off easy ". My sentiments exactly. Again, I do apologize if I missed something.

 

[Ypedal]

I got what i expected, and for the price it was not a complete waste ( I have a 1700$ DOA pack on my shelf.. got me all of 10 minutes of run time.. oh the early days.. :lol: )

Headway is about batteries, not BMS's, yet, and this was known beforehand.

EVC is clearly still learning about their product and have gotten ahead of themselves selling un-tested packs but the cells are ok imo.. they are very much aware of this right now and i do wish them to stay around and improve... time will tell what happens on that front but i see no reason to bash them anymore than the facts support, this review imo was fair and factual. :wink:

My customer DID in fact buy my e-bmx and has been using it for a few weeks now.. have not heard back recently, i need to check up on him and see how things are holding up.

 

[redorblack]

I'd like to defend EV Components a bit. They are not shipping the smaller bike packs because their own testing showed the BMS's that HEADWAY built in didn't match the current capacities of the cells and they were having cutouts. They didn't know the larger packs would do the same thing because no one had reported it and they didn't have a chance to load them. When I went to buy my 48V/10Ah pac, I told them about the issue Ypedal experienced and they let me know that they were seeking a solution of their own. They have probably contacted a couple of people here for input, I suggested it and pointed them at this thread. Their main business is large systems for electric cars and they are furiously building Zilla controllers.

They are supplying exactly what Headway provided. They have a bunch of inventory they won't sell because of the problems they discovered with the smaller packs. I got my pack knowing that I wouldn't be tripping the BMS that Headway made part of the battery pack due to Ypedal's testing. Get that part through your heads, this is NOT EV Components fault. If you bought one of these packs from the other Headway vendors you'd get the identical item. But EV Components IS working on a solution, I do not know if any other suppliers are or if any of the other suppliers even have the ability to do anything but tell you to complain to Headway. EV Component's main business is building components... bad ass tire burning components for Electric cars that WORK. They are working on a solution, I don't know how long it will take, they don't have infinite resources, but I do know that they KNOW EV and are dedicated to it. They are not just an importer sticking people with crap product.

I'm ecstatic with my pack... I knew I wouldn't be drawing the amperage that the bad boy monster builds here do. My pack is balancing beautifully, performing flawlessly, giving me a 27-28mph speed on the flats without pedalling. I am getting all the range I need, haven't used more than a 1/3rd of it's capacity yet even riding further than I could get at slower speeds with my SLA setup.

What people need to take from this thread is that the BMS is a problem IF you need that 5C capability. If like me you aren't ever going to go past 3.5C or so (Max amp draw I've recorded is 28 amps on a ride with a 10% grade) it isn't an issue.

I'm wondering about the motives of the person pm'ing people that EV Components sucks. Have they spoken with the battery guys at EVC?

My sole complaint is that I recommended that they update the website, the photos don't match how the products actually appear. I'd also like to see them change the description of the packs that they know won't meet the specs Headway gave for the included BMS. But I know they are swamped with large orders of cells and Zilla products. Unfortunately that leaves the website as secondary. I think that is the biggest crime they've committed.

 

[TylerDurden]

I got a private message from a member quote: "ypedal got ripped-off and let EVC off easy ".

Who's the chickenshit that wouldn't post publicly?

 

[Speedfreke]

Report this postReply with quoteRe: RETAILERS AS MEMBERS?
by TylerDurden » Fri Oct 16, 2009 12:34 am
"We have special prizes for suppliers who BS... we feed them their bowels, gleefully torn from between their ears."

 

[Lock]

and yer point is?

 

[frodus]

Ypedal and I have worked together initially on working something out, and we actually really appreciate the feedback he's given us. Thank you for that Ypedal.

We did order a TON of these packs and expect (as we're used to with US products) that they would meet specifications. While the batteries met spec, the BMS's in some of these packs did not. They cut out early and headway does not seem to be very responsive in providing a quick solution. There's really no way to fix them in the field.

We stopped selling some of the packs that had issues with their BMS, and in some cases, sell them without BMS due to the issues with the built in units. We have tried very hard to find solutions and work with each and every customer that has issues, Ypedal knows this and has been very easy to deal with. If there are issues, we have no problems refunding, we stand behind our product and when it fails, we refund (within reason).

In the future, until headway can prove they have working BMS systems that meet spec, it apears that we will only be offering the cases, batteries, building blocks and busbars. We are looking for solutions when it comes to BMS at the moment but have been slammed because Dave Kois was in the hospital getting surgery. He's back now and we're working on getting caught up.

If ANYONE in this thread, has a pack that has BMS issues, please contact me so we can resolve.

travis@evcomponents.com

Thank you
Travis Gintz

 

[CroDriver]

Hi Ypedal

Nice thread, thank you all for sharing the information!

Yet Another Dumb Question Alert!

Maybe I am just out of my league but could I ask yet another dumb question? What are you doing and, more importantly, why are you doing it? Didn't you say that battery came with a BMS? Why are you hooking up 2 BMS's to the battery? Did you remove the stock BMS that came with the battery? Or are you doing something completely different?

Wonder no more, i am replacing the original BMS with 2 bigger one's !

The Headway cells are capable of 5C ( 5 x 10ah ) ie: 50 amps, but the original BMS is going into protection mode when it should not.

If you wanted to use this battery in stock form, it would work just fine on a 500w ebike, but this pack is for my e-bmx that has a current limit of 46.5 amps and the original BMS canot cope with this.

The 2 BMS i'm installing now are modified units with a higher power limit, they " should not " shut down even when i crank the throttle from a dead stop, and they work much better at ballancing the cells compared to the original one.

:wink:

I thought the cells are capable of delivering 15C or even 20C


5C

10C

15C

 

[Ypedal]

At higher than 5C they would get considerably hot and i would fully expect shoter life from this treatment.. can the cells " do " it.. yes but at too much voltage sag. :wink:

 

[redorblack]

What is the time scale on those graphs?

Dropping to 2V at 15C? Isn't that a bad bad thing? Looks like 10C is acceptable as they stay over 2.5v until they drop. Not an issue at less than 2.5C constant that I'm running mine at, but could be a serious issue for a high power application.

Also is that the S or P version? The P is the one that is supposed to be able to pulse to 15 or 20 C for a few minutes.

 

[frodus]

graphs are in seconds on the bottom. Rates above 5C are meant to be short-term rates, the batteries should not sustain 10C or even 15C rates for more than 10-20 seconds. It hurts their Wh output as well as their total lifetime. Graphs are for the S version. The P version is a 8Ah cell.

 

[dequinox]

Does anyone know anything about those Sky energy cells they sell? I've heard less than optimal things about the Thunder sky...but I am wondering if these are the same thing.

 

[frodus]

how long ago were these "less than optimal" things?

there was a big thing a couple years ago from some people that got bad cells from a bulk order...

but nothing recently, and TS and SE honor replacing cells under warranty....

 

[Ypedal]

Update.

So it's been a while.

Last week, dude dropped by to have the bike/battery checked out, reported early cutouts and loss of performance. I strapped the pack on my back and saddled up for a test ride.. everything seemed normal to me. Pushed hard for 10 minutes and determined all was well.. told him to not worry and to give it hell !. :twisted .. and let me know if problems persist.

So a few days ago he dropped in again saying it was cutting out at the 1.7ah mark.

Alright.. so i check closer and find that the copper strands had slightly pulled away from the jacket and could have been possibly causing a slight short ( unlikely, but possible ) . so i removed the anderson housings and checked to make sure the connection was still solid and it was..

Last night i charged the pack and took the bike to work this morning. oh man.. that BMX is a riot !!!.. i freakin love it !.. gotta build another one.

No problems getting to work, 2.5ah, on the way home i ran full throttle all the way, detour to local park, past my house, up the street and back, at the 7.8ah mark she cutout..

Tonight i opened up the lid, charged it up to observe the BMS led's and something weird is that all 8 LED's light up on the BMS but it does not shut down the charger.. not sure why that is but testing continues.

 

[Russell]

Tonight i opened up the lid, charged it up to observe the BMS led's and something weird is that all 8 LED's light up on the BMS but it does not shut down the charger.. not sure why that is but testing continues.

Don't have one of those fancy BMS boards but don't the LED's simply indicate the shunts are active for a particular cell? Again I don't know about that BMS but most I think only open the charging circuit if a cell has tripped the upper volt limit detect circuit which is most likely to happen if the cells are badly out of balance or if a high charging voltage is used.

-R

 

[drewdiller]

FWIW, I've been sitting on a lazy 36V 10Ah pack I got from evcomponents. Travis Gintz has been pretty helpful, my changes to the battery have been far slower.

I consistently got 2.6Ah out of it before it cut out.

First I replaced the BMS, which was a learning experience -- this is turning out to be both a frustrating and fun hobby. New BMS made no difference.

Travis suggested I had a weak cell. I opened the pack again and found one cell that measured 2.4V (!!!) while others measured 3.27V +/- 0.03V. I bought a single cell charger, and foolishly charged the one cell while the rest of the pack wasn't totally charged.

I got 3.2 Ah the first ride after that, put it on the smart charger over night, after seeing the fully-charged LED light up and turn back off in approximately 5 second intervals (question, was I watching top-end balancing happen?). Took another test ride last night, I voluntarily stopped after 4.4Ah (out of boredom and it being near midnight) and was still drawing 7 to 10 amps with no voltage drop below 36V (usually hovered around 37) -- left it on the charger again last night and will give it a longer test ride soon.

If I have problems, I'll show up again with pictures, as I was quite puzzled about the wiring when I replaced the BMS. I thought it's supposed to go like this, according to the diagram I got from the new BMS:

Connect "B-" on BMS to battery cell 1 negative pole.
Connect "1" on BMS to battery cell 2 negative pole, then follow a pattern: connect "N" on BMS to battery cell "N+1" negative pole, if less than 12.
Connect "12" on BMS to battery cell 12 _positive_ pole.

...for a total of 13 leads from the battery pack to the BMS. Is that right?

If that is right, I'm not sure that cell 7 was wired correctly (from the day I first received it).

 

[Ypedal]

fully charge, then using the single cell charger fill up every cell ( yes, this takes time ) one by one to fully charge the entire pack 100%. :wink:

 

[drewdiller]

So, I'm pretty convinced I never had a bad BMS. I think my pack arrived with one cell that wasn't charged, and the BMS couldn't make up the very large difference, the end.

I broke my CA recently, but I went for a ride today, and I got 17 miles before I got bored and stopped. w00t. When I take my battery off the charger, it reads a very snazzy 43.6V ( it's 12 in series, so ceiling of 3.65V each comes to 43.8 ).

"Simple answer is usually the right one."

 

[Ishikawa]

Look what I found.
View attachment battpack.jpg
Looks familiar Ypedal? I bought this from beast 775 last week. It's interesting the battery pack traveled across the continent and ended up on this side of the country.
When we checked the voltage it was about 48v at the connector. But over 50v at the cells. I was not sure if it's any good but I took the chance, the price would be good IF the batteries and BMS are ok.
After I came back home (1hr drive) I checked the voltage again. It came down to 40v but 50v at the cells. And it won't take charge, charger LED stay green. It must be something wrong with BMS. Upon close examination, I found this
View attachment brokentm.jpg
It looks like a thermistor wire broken. It was hidden behind a lot of tapes. I touched the solder pad with the wire, charger LED turned red and started to charge. I did not have to keep the wire connected, charger kept going on. After 10 min or so LED turned green but some of LED on the BMS stayed on and gradually went off one after another, took about 15min. Checked the voltage, it's 27.5 and 27.6, 55.1v total, a little lower than it supposed to be so I drained few Ah and charged again. Took 15min to recharge but when BMS LED went off the voltage were the same as before. So I checked each cells, surprisingly it's in between the lowest of 3.38v to highest of 3.50v. I thought BMS would charge the cells equally. Anyway I will solder the wire properly and charge each cell separately with single cell charger and see what happens.