Headway batteries advice

[Tommy L]

Gotta love that cycle analyst!! Every ebike should have one.

Now where is that "Like" button!


LIKE!




I couldn't agree with you more! The Cycle Analyst is a great fuel gauge as long as you have your Controller Shunt
value entered correctly.
Always a learning curve with new stuff.


Tommy L sends......

 

[Tommy L]

We are probably not that efficient, more like 12-15 wh/mile, although that is fairly close. Our trikes are not light, mine with the full suspension and hers with heavy steel construction but they do cut through the wind and are comfortable. Important features for us old folks.
otherdoc

Hi Other Doc!

(9 wh/km is around that 12-15 wh/mile) So we are right on the money! We have the Bionx systems on the trikes.
I really like the Bionx for getting my workout. Set the level of desired help and pedal away. It's nice to maintain higher
speeds and not slow down on hills or slowing due to headwinds. My Bionx is a 2008 system and the battery is shot. I built a headway pack 12S1P 38120S (360 w/h). Then I built a 12S2P from the 38120HP cells (600 w/h). They seem to work fine.
I can manually ReGen on my screen, but for some reason my reedswitch on the brake is not engaging the ReGen,
I have Dual Hydraulic Disk up front, so not a big worry. My max speed down a hill was 54kph. On a Flat is around 40kph.
I also have Big Maxxis Hook Worms all the way around, so my rolling resistance is greater than it could be, but then
again, I'm enjoying the comfort

Tommy L sends.......

 

[Alastor]

Nice build man its nice to see another using protecting gear on that speeds and power.

 

[Tommy L]

Nice build man its nice to see another using protecting gear on that speeds and power.

Alastor!

Thank you. And even with the Gloves, Jacket, Boots, Pant and Helmet, Off road moto armour might still be a better choice.
The whole point of Volting up on my 9C2810 was to experience how Watt Hours are consumed vs different speed and to
see efficiencies.
If I decide to run it that fast on a regular basis, then DOT Rims, Tires and the likes are a must.
I will either build an Emoto or a bicycle style frame with in frame battery design. The BackPack is stealthier, but I'm done with carrying 1.2kw of LiFePO4 on my back (and LiCo will NOT go on my back) :wink:

Tommy L sends.....

 

[hardym]

I've ordered a Headways battery from EV Assemble. Took about 4 weeks to recieve, but I got it, and have gotten some support from the owner, michael who ocassions this board. I only have about 1200 miles but it seems to be working ok.

Here are a couple data points:

Headways 12 AH 48V with charger and shipping to US:
EV Assemble: $393 + 98 = $491
Headways HQ: $664 + $30 = $694

So, waiting for overseas shipment can save you 30%.

Mark.

 

[Tommy L]

I've ordered a Headways battery from EV Assemble. Took about 4 weeks to recieve, but I got it, and have gotten some support from the owner, michael who ocassions this board. I only have about 1200 miles but it seems to be working ok.

Here are a couple data points:

Headways 12 AH 48V with charger and shipping to US:
EV Assemble: $393 + 98 = $491
Headways HQ: $664 + $30 = $694

So, waiting for overseas shipment can save you 30%.

Mark.

If you can, purchase a 3.65v charger. If your pack gets way out of balance, you can charge individual cells.
Know your watt hrs and try not to use more than 80% and don't put more than 2C load on them.

I just got my B168 Charger that charges up to 8amps per channel! I tried it out last night, what a sweet unit for
balancing out packs and maximizing capacity.

A GOOD BMS would be choice too! The Smarter, the better.


@dnmun
I would like to try a BMS. Where can I get that 73.00 dollar delivered unit from?

Tommy L sends.....

 

[dnmun]

sacko was the guy who bot one. they say that the setpoints are adjustable but he got stuck with the factory settings so we don't know what they are yet.

this is the one he bot. i have a similar one for 12S lifepo4 that came from BMS battery. these guys are the ones who make all the BMSs for people like BMS battery:

http://www.bestekpower.com/888v24spcmbmspcbforli-ionli-polymerbatterypack/PCM-D131.html

i put a switch on the circuit current on mine and you could do the same thing with that one. to turn off the battery when connecting to the controller or when leaving it unused for a long time, or prevent it from being stolen.

 

[JimmieD]

Not here to give advice or to promote, but to provide information. :wink:

So they claim 20C for this cell, anyone believe this?

http://headway-headquarters.com/38120hp/

Yes, just like the A123 for 30 or 60C. The test is done with ONE cell and there is nearly no voltage during this massive current draw.

If you need a working voltage with current then one must build it with this in mind.

The minute you put them from Cell into a Battery configuration, there are losses thru the busbars and the likes.
Ask the Battery to do to much, then it's a big heating element. Sure, some spikes are tolerated for brief periods, but once too much
heat builds, the resistance increase and then the energy just turns into more heat.

Tommy L sends....

The testing may be done with ONE cell in at the factory but for me that is not quite good enough! :wink: Also the 38120HP cell is 25C pulse, will need to update the site, still had the old 38120P information there.

Here is are tests that I have done with a 4S1P battery (not a just a single cell!) using the 38120HP cells with a CellLog monitoring, load test was completed using a 500A carbon pile tester so although not a true 'pulse' test, it does show the capabilities of the cells. Purpose of this basic test: To check to see if random cells (not specific 'Test' cells) that were pulled from inventory performed as stated on the spec sheet, check the upper limits of the cells capabilities beyond what the spec sheet states, and finally to check to see how much voltage difference between cells that were not 'matched' but pulled from 4 random cases. There is voltage sag as with ANY chemistry once loads are applied, but the graphs should speak for themselves if the cells are capable of a 25C pulse as spec'd. Enjoy! BTW, the ampere load at the top left corner was actual through both clamp on ammeter and through a shunt, picture title was the reading on the carbon pile tester.

 

[hillyterrain]

Hi Jim,

thanks for the info. The one thing keeping me away from the batteries right now are reports that the negative pole end is epoxied and prone to cracking. Has that issue been addressed with a better solution?

 

[dnmun]

i have not seen the epoxy break on any of my cells. i think it is more like a polyurethane sealant that sets up hard, not epoxy, jmho.

 

[JimmieD]

Headway cells are easy to build packs with. Using the plastic cell holders bus bars and screws is hard to mess it up. If a cell goes bad then not too big a job to replace it.
Headway HQ is a direct descendant of the evcomponent outfit that had lots of angry customers left holding the bag. How that ever worked out I do not know.

We ARE NOT "a direct descendant of the evcomponent outfit", and if you do not know how it all worked out, it would probably be prudent to keep your negative and false comments to yourself! IF you want to know (at least the latest that I know of), simply check out the controversial Jack Rickard over at EVTV.ME, December 9, 2011, video blog, between 23:45 to 35:15.

also i think jimmyD is top notch help too. too bad he got tarred by the evil from EV components for no reason.

Thanks dnmun, it is appreciated.

I think you might be mixing up HQ with that notorious outfit... heck if I can remember their name either ... but I think they were/are not afiliated. let's see how everyone elses memory is holding up though

Thanks scoot, your memory did you well.

Apologies to the OP, but I will continue to defend our company and reputation.

 

[JimmieD]

Hi Jim,

thanks for the info. The one thing keeping me away from the batteries right now are reports that the negative pole end is epoxied and prone to cracking. Has that issue been addressed with a better solution?

You are very welcome! We have never experienced breaking of the epoxy and have not had any requests for replacements due to breaking epoxy. The primary reason for returns are us are due to poor threaded or cross threaded cell ends.

The epoxy does break IF the torque specifications are not followed, I've attached the information.

 

[MD.]

For whatever it's worth here's what I have to add and want to know about on this thread.

Yes, LiFePo4 cells have some level of sag. If you put together a 12s pack and the operating voltage is 36v after sag, then you have a 36v pack. Why are you expecting a 41v pack with 12s? This doesn't make sense to me. When that 36v pack is drained it goes down to 31v to cutoff. That seems about right to me. Can someone explain why they would expect something different? If you're talking RC Li-Co/LiPo then yes, then a huge sag like that wouldn't be expected. Everything I've read on LiFePo4 chemistry, this sag is expected. The same thing seems to be true for Lead Acid. I don't see numerous posts where people complain that a 12ah lead acid battery only delivering 8ah. Why or why not? This is confusing to me.

The graphs that JimmyD posted look good to me however these are not the cells that the original poster asked about. Does anyone have graphs of the 15AH cells that the original poster asked about? These are spec'd at http://headway-headquarters.com as "LiFePO4 40152S 15000mAh cells have a continuous discharge rate of 3C, and maximum pulse of up to 10C". What I want to know is do the cells that the original poster asked about have a continuous discharge of 3C and pulse of 10C or not? If you read this thread, it seems like most opinions are 1C or 2C and not 3C. However, if you search the internet, most people agree that they do perform at 3C. What is the truth here?

I purchased 16 of the 40152S, 15AH Headway cells expecting to pull 40A from them, about 2.7C. I did not purchase them from Headway-Headquarters.com but would have as they have a good reputation in my opinion. Instead, I purchased them from this for sale thread on here. The price was competitive with direct quotes from China, shipping was fast, and communication was excellent. Overall I paid around $600 for the cells, a 50A bms, and 6A charger. I was quoted about $540 for the same setup built and shipped from a couple different Chinese sellers. I was happy to pay an extra $60 for local dealers.
http://endless-sphere.com/forums/viewtopic.php?f=31&t=47361

I did have a problem with one cell epoxy breaking loose as I didn't follow the torque specifications. That was my fault for not following the instructions that I was aware of. It's fine as the pack is modular and no problem just to replace a cell.

The pack is very, very heavy and in hind sight, a Ping LiFePo4 or if real A123 cells were available, those would be a lighter choice.

My 2c.

 

[JimmieD]

Hi MD.

Thanks for redirecting back to the OP about the 40152SE, was a bit hot under the collar

The graphs that JimmyD posted look good to me however these are not the cells that the original poster asked about. Does anyone have graphs of the 15AH cells that the original poster asked about? These are spec'd at http://headway-headquarters.com as "LiFePO4 40152S 15000mAh cells have a continuous discharge rate of 3C, and maximum pulse of up to 10C". What I want to know is do the cells that the original poster asked about have a continuous discharge of 3C and pulse of 10C or not? If you read this thread, it seems like most opinions are 1C or 2C and not 3C. However, if you search the internet, most people agree that they do perform at 3C. What is the truth here?

I do not have any recent data except what was provided to me from Headway, will work on a few 40152SE discharge tests and post them on this thread in the next few days.

For what it is worth, here is the information from Headway, and

I did not purchase them from Headway-Headquarters.com but would have as they have a good reputation in my opinion.

Thank-you MD., much appreciated.

 

[MD.]

Thank you for such a fast response Jimmie. And thank you for trying to deliver the accurate information.

Based on the manufacturer graphs that you did post, it looks like at 3c and 5c they do perform near capacity. 10c sustained does seem to be too much. What do you expect you'll find with your tests? Is a 3c to 5c draw within the specs of the 40152SE?

 

[knighty]

my 24s 72v10ah pack from bms battery is sagging too much for me

not sure how much power I'm pulling, but with an 80amp controller it's enough for the bms to shut the battery off

no amp meter on bike yet, but with the back wheel up, twisting throttle to spin up wheel and then applying brake the pack was sagging from 80v down to 45v and under

I'm thinking about changing to the red cells, but... your web page says they're 20C, then the link to a spec sheet says they're 10C ?

 

[Tommy L]

Yes, LiFePo4 cells have some level of sag. If you put together a 12s pack and the operating voltage is 36v after sag, then you have a 36v pack. Why are you expecting a 41v pack with 12s? This doesn't make sense to me. When that 36v pack is drained it goes down to 31v to cutoff. That seems about right to me. Can someone explain why they would expect something different? If you're talking RC Li-Co/LiPo then yes, then a huge sag like that wouldn't be expected. Everything I've read on LiFePo4 chemistry, this sag is expected. The same thing seems to be true for Lead Acid. I don't see numerous posts where people complain that a 12ah lead acid battery only delivering 8ah. Why or why not? This is confusing to me.

I've done resistance load tests for continued use of the Headway 38120HP.

I'm going to take the MYSTERY out of the equation. Ever fill up a glass with water too quick?
Usually you fill quick then back off and top up. Same with LiFePO4.
Higher current/lower voltage in the beginning of charge, then as the Cell charges up, the current backs off and the
voltage starts to increase. The finish voltage of 3.65v per cell is where the the Cell is topped off and completely full.
The voltage between 3.3 and 3.6v is surface charge. The minute you put the 3.65v cell under load to 3.3v and release it,
it will recover to maybe 3.4v. These cells have a working voltage of around 3.2v with a 2C load

On one of my tests on a 4s4p 12.8v nominal pack 32ah with a 850watt load (70amps) as follows:

Tommy L sends.....

 

[Icewrench]

We ARE NOT "a direct descendant of the evcomponent outfit", and if you do not know how it all worked out, it would probably be prudent to keep your negative and false comments to yourself! IF you want to know (at least the latest that I know of), simply check out the controversial Jack Rickard over at EVTV.ME, December 9, 2011, video blog, between 23:45 to 35:15.

http://endless-sphere.com/forums/viewtopic.php?f=3&t=26240&p=379939

http://www.diyelectriccar.com/forums/showthread.php/headway-headquarters-warning-50912.html

 

[JimmieD]

Thank you for such a fast response Jimmie. And thank you for trying to deliver the accurate information.

Based on the manufacturer graphs that you did post, it looks like at 3c and 5c they do perform near capacity. 10c sustained does seem to be too much. What do you expect you'll find with your tests? Is a 3c to 5c draw within the specs of the 40152SE?

I expect them to perform well at up to 5C, but anything above that, watt power will suffer due to loss of energy through heat dissipation from the high discharge rates, but will know more after playtime with them this weekend. Will do a 1C, 3C 5C, and 10C continuous discharge tests and get them posted up here.

I've done resistance load tests for continued use of the Headway 38120HP.

Thanks Tommy L for putting up your experience and results!

I'm thinking about changing to the red cells, but... your web page says they're 20C, then the link to a spec sheet says they're 10C ?

Thanks for bringing it up, went in and updated, the continuous spec is 10C and the pulse is 25C for the 38120HP cells.

Glad to see Icewrench is still such a fan! Besos! :lol:

 

[docnjoj]

Well it looks like there are Headways in my future. Especially since A123 is getting problematic. Headways are also easy to assemble and the extra weight is of no consequence on a trike. At least not at 1P.
otherDoc

 

[hillyterrain]

This is all new to me so I'm just wondering why headway / round cells instead of LiFePO pouch cells? Some vendors assemble them in modules free of charge, I guess pouch cells waste less volume and might even have higher C? So why go with round cells? Honestly I don't know, thanks for explaining..

 

[docnjoj]

This is all new to me so I'm just wondering why headway / round cells instead of LiFePO pouch cells? Some vendors assemble them in modules free of charge, I guess pouch cells waste less volume and might even have higher C? So why go with round cells? Honestly I don't know, thanks for explaining..

Easy assembly and replacement if a cell goes bad. I have had that happen with my A123 pack and agniusm's kit makes it fairly simple to replace. Other pouch cell packs, even Pings, are a nusance to replace cells. Also Ping is really only 2-3C as are these. That is all I need. If the A123 situation improves I may do another of those next. The Headway plastic blocks and screws are really cool.
otherDoc

 

[Tommy L]

I made T6 6061 Aluminium bus bars and sent them out to get plated
Check out the pics in my build thread! Can you say: "BEEFY" 0.25 thick.
No thermal loss up to 300amps I believe! lol

http://endless-sphere.com/forums/viewtopic.php?f=4&t=39480


Tommy L sends......

 

[JimmieD]

Got tied up, but here is the testing for the 40152SE 15Ah cell. The ambient temperature was 19*C during the tests, the cell was recharged at .5C, final high external temperature reading of the cell after 10C discharge was 63*C.

Cells seemed to perform better once chemistry heats up, near end of 5C test and throughout the 10C test appears to be a little noise in the line, will double check connections, retest and if different or if noise is gone, I will post. The cell is spec'd to pulse discharge at 10C which may be the reason for the fluctuations in the graph, will retest to double check.

Could not quite fine tune 10C voltage reading, software showed 60mV lower than actual voltage at cell terminals, so test is slightly off, but again, it was for the 10C continuous which was supposed to be a 10C pulse per the spec sheet.

Enjoy!

 

[MD.]

Thank you Jimmie for running these tests and posting the results!