New prices for Headway cells!!!!

[snowranger]

I think one of the primary reasons a lot of people are going to the HobbyKing lipos is because of the lack of good and reliable LifePO4 alternatives. Although Headway makes good cells ( I have a pretty reliable pack), I had to take a chance buying it from what I did not know at the time was an unscrupulous dealer. Don't get me started on my first lfe pack, which ended up as a brick even though it was from the most reputable duct tape battery seller out there.

I'm now going with HK lipos for my next build because of what many members are reporting as a product with high performance and good value, and HK actually has decent customer service.

[neptronix]

Don't get me started on low price lipo that turns up with 10% crap packs, relatively short lifecycle and is not classed as a safe battery by any standards. If you asked the Manufacturer of these low price LiPo cells to supply Ebike packs made from RC Lipo, they would tell you they are not safe and not recommended for other reasons also. They manufacture large format LiPo cells for EV, they are not as high C or same type, or as cheap, but they are fit for purpose. I've spoken with the Manufacturer and that is what they did say. Many people seem willing to accept the shortcomings of cheap RC Lipo and enjoy the high performance it offers at a good price, but don't kid yourself that they are truly better value in the long run or that the shortcomings are there, they are real and there is a real possibility of a fire. There are pros and cons, it's not all good.

Yes, they are temperamental, and a BIG liability, but fantastic if treated properly.
Let me tell you something though. I for one would be willing to pay for large format, mid-high quality lipo. 10ah or 20ah cells would relieve all of these balancing issues and make lipo much safer. Not having cells mismatched by ~500mah would further increase the amount of safety.

The benefits ( weight, discharge, size ) far outweigh the risks in my opinion, and the price is a bonus.
Would you sell large lipo cells if you had the opportunity to do so? dunno if you saw that thread about the Chinese 20ah packs a while ago, but there is a hell of a lot of interest in cells of that size.

[auraslip]

I think one of the primary reasons a lot of people are going to the HobbyKing lipos is because of the lack of good and reliable LifePO4 alternatives. Although Headway makes good cells ( I have a pretty reliable pack), I had to take a chance buying it from what I did not know at the time was an unscrupulous dealer.

Nailed it. For the same reason I'd consider cell_man local. He posts on here. He understands our ebike needs. If you have a problem, I trust he'll help. And not to be xenophobic, but he speaks english well(not good).

For the same reason, It's good to see US sellers of headway.

[Jeremy Harris]

Nailed it. For the same reason I'd consider cell_man local. He posts on here. He understands our ebike needs. If you have a problem, I trust he'll help. And not to be xenophobic, but he speaks english well(not good).

For the same reason, It's good to see US sellers of headway.

Not surprising that cell_man speaks good English, as he is English, but who just happens to be living in Shanghai. IIRC his name's Paul.............

Jeremy

[cell_man]

Nailed it. For the same reason I'd consider cell_man local. He posts on here. He understands our ebike needs. If you have a problem, I trust he'll help. And not to be xenophobic, but he speaks english well(not good).

For the same reason, It's good to see US sellers of headway.

Not surprising that cell_man speaks good English, as he is English, but who just happens to be living in Shanghai. IIRC his name's Paul.............

Jeremy

Yes that's right Jeremy on both counts Paul, originally from London, of Irish descent, living the dream in Shanghai

[cell_man]

Don't get me started on low price lipo that turns up with 10% crap packs, relatively short lifecycle and is not classed as a safe battery by any standards. If you asked the Manufacturer of these low price LiPo cells to supply Ebike packs made from RC Lipo, they would tell you they are not safe and not recommended for other reasons also. They manufacture large format LiPo cells for EV, they are not as high C or same type, or as cheap, but they are fit for purpose. I've spoken with the Manufacturer and that is what they did say. Many people seem willing to accept the shortcomings of cheap RC Lipo and enjoy the high performance it offers at a good price, but don't kid yourself that they are truly better value in the long run or that the shortcomings are there, they are real and there is a real possibility of a fire. There are pros and cons, it's not all good.

Yes, they are temperamental, and a BIG liability, but fantastic if treated properly.
Let me tell you something though. I for one would be willing to pay for large format, mid-high quality lipo. 10ah or 20ah cells would relieve all of these balancing issues and make lipo much safer. Not having cells mismatched by ~500mah would further increase the amount of safety.

The benefits ( weight, discharge, size ) far outweigh the risks in my opinion, and the price is a bonus.
Would you sell large lipo cells if you had the opportunity to do so? dunno if you saw that thread about the Chinese 20ah packs a while ago, but there is a hell of a lot of interest in cells of that size.

Well I would like to develop the battery business more and offer more options, but it costs a lot of money to buy sufficient quantity to be competitive. Not to mention it's also a big chance if they then turn out to be crap. I don't like selling stuff that goes wrong, it makes me feel bad and is a real PITA. A123 cells just do not seem to go wrong and that's good for me. I'm not interested in stringing together packs from the cheapest stuff I can find. There's enough already doing that and it just doesn't appeal to me. Let the bargain hunters get on with it, maybe their second pack will be from me

Big format cells are good, but they also have drawbacks. Cylindrical cells are good in some respects, not so good in others. Pouch cells have advantages.... you get the picture. It is very simplistic to say this is the best and that's that. There are pros and cons for every format and chemistry.

[neptronix]

Well I would like to develop the battery business more and offer more options, but it costs a lot of money to buy sufficient quantity to be competitive. Not to mention it's also a big chance if they then turn out to be crap. I don't like selling stuff that goes wrong, it makes me feel bad and is a real PITA. A123 cells just do not seem to go wrong and that's good for me. I'm not interested in stringing together packs from the cheapest stuff I can find. There's enough already doing that and it just doesn't appeal to me. Let the bargain hunters get on with it, maybe their second pack will be from me

Big format cells are good, but they also have drawbacks. Cylindrical cells are good in some respects, not so good in others. Pouch cells have advantages.... you get the picture. It is very simplistic to say this is the best and that's that. There are pros and cons for every format and chemistry.

I suppose you could buy a couple samples here and there and find yourself a nice large format lipo over time. Go buy some packs and ride on them for a few months maybe. The discharge rating, high voltage, low weight, and lower cost of lipo makes up for the cycle life in my opinion, and i think a lot of people agree. There has got to be some company out there that's making good lipo; i've seen good lipo being parted out from industrial telephony systems and backup power systems recently.

Here is the thread i was referencing: http://endless-sphere.com/forums/viewtopic.php?f=14&t=23029

BTW, what are the disadvantages of large format pouch cells? in my opinion they seem like the holy grail.

[neptronix]

Or if you can make 20ah A123 cells magically appear, that would be cool too

[oatnet]

Or if you can make 20ah A123 cells magically appear, that would be cool too

Paul has already done that trick once but I don't think he can pull it off again!

-JD

[cell_man]

Yes I may well get the 20Ah A123 cells again, but they are not going to be as cheap as HC LiPo and price seems to be the number 1 priority for most of the HC LiPo flock

[auraslip]

price seems to be the number 1 priority for most of the HC LiPo flock

That doesn't even make sense to me. Headway p 8 ah cells are PRICED the exact same as hk lipo. And you only need a charger, and an inexpensive bms (compared to dedicated LVC and RC chargers). These are 10c cells, so at a minimum you're looking at a 80amps continuous. What ebiker needs more than that? If you do, your gonna need enough AH for range. That means a bigger pack which means 160amps continuous.
Plus lipo life cycle is 300-500, compared to lifepo4 @ 1000-2000. That right there should tell most commuters that lipo is gonna end up costing them 4 times as much in the end.

And that's not even counting the batteries you'll ruin with what ever handy made BMS you rig up.

Then again most of the LIPO guys, they take pleasure in handy rigging BMS and playing with batteries. Playing with different voltages does sound very appealing and I definitely share their enthusiasm for how powerful the stuff can be, but unfortunately not a similar bank statement.

[neptronix]

Erm, the price is quite different.. here is a comparison

for 36v and 10ah;
headway 10ah cell X 12 = $216
zippy/turnigy 5s 5AH 20c pack x 4 = $164.84

nominal/peak amps:
Headway pack : 50/100
Zippy/turnigy: 200 / 300(?)

Weight difference:
Headway 10ah pack = 302g x 12 = 3624g
Zippy/turnigy pack = 700g x 4 = 2800g

Cycle life:
Zippy/turnigy = 300-600 cycles our use
Headway = ~1500 cycles?

Size difference:
? ? ? i know the cylindrical cells here are gonna lose BAD for sure..

p.s. you could use a BMS with lipo as well.. or you could use a hobbyking charger on lifepo4.. so the cost of the external stuff is a bit questionable. Lipo chargers tend to cost more because the stuff is more high amperage. You won't be charging that 10AH lifepo4 pack at 30amps, will ya?

Yes headways are a better value, but they have their downsides. Discharge rating, weight, and size are what attract me to lipo. It is not all about cost or cycle life.

[auraslip]

Do you know of a BMS that works with lipo?

[neptronix]

Do you know of a BMS that works with lipo?

Yes, and reasonably priced as well.
http://www.all-battery.com/protectivepcbsforli-ionandli-polymerbatterypacks.aspx

http://www.tenergybattery.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=378&category_id=25&manufacturer_id=0&option=com_virtuemart&Itemid=27

^-- only bad part with these is that they allow discharge to 2.5v per cell.. not acceptable.. maybe fixable by changing resistors?

Other manufacturers also sell BMS's.. with an option to do lifepo4 voltage or lipo voltage.

[auraslip]

The tenergy one says it's charges to 4.35v per cell - that'd be very bad for the lifespan of a pack charging that high. Most people here charge up to 4 or 4.1. I think those BMS are designed for different chemistries. I think the goodrum fetcher BMS can be used with lipo, but you need to replace some resistors. I wonder why no one is doing that?

Btw here is what I got when I checked cell prices from my sources:

36v 10ah
headway 10ah cell x 12 = 192
prebuilt pack headways including 5 amp charger 36v10ah = 315
15c hk lipo 5s 5ah x 4 = 172
cost to take care of lipo = ???
cost of time to take care of lipo = ???
jk about the last one

All prices include shipping.

Btw you vast overestimated the headway discharge rate. IIRC it's more like 3.5c for the regular cells, and 8c for the P "power" cells. So 35 amps and 80 amps respectively.

But then again, if you are building a serious commuter bike, you'll want range. So if you get a 20ah or 16ah pack your continuous power rating is much higher.

[neptronix]

The tenergy one says it's charges to 4.35v per cell - that'd be very bad for the lifespan of a pack charging that high. Most people here charge up to 4 or 4.1. I think those BMS are designed for different chemistries. I think the goodrum fetcher BMS can be used with lipo, but you need to replace some resistors. I wonder why no one is doing that?

I suppose that most lipo guys like myself are hobbyists and don't mind a little bit of inconvenience. Me, i just chop off a bit of the top and bottom of my charge.

Btw here is what I got when I checked cell prices from my sources:

36v 10ah
headway 10ah cell x 12 = 192
prebuilt pack headways including 5 amp charger 36v10ah = 315

If you can get them for that much, they are a deal, although it sounds like you would be getting them from ev-assemble or something, which i would avoid like the plague.. erm actually maybe we shouldn't be talking headway prices, to respect the original poster.

Btw you vast overestimated the headway discharge rate. IIRC it's more like 3.5c for the regular cells, and 8c for the P "power" cells. So 35 amps and 80 amps respectively.

But then again, if you are building a serious commuter bike, you'll want range. So if you get a 20ah or 16ah pack your continuous power rating is much higher.

Ahh, all the official specs i've seen say 5c but i figured that was a bit high.
Yeah, 3.5c isn't bad if you have 16ah.
The problem with 16ah is fitting the damn things in the frame though.
Meanwhile i can fit 20ah 10s into my frame, no problem. And the packs are so narrow that they don't interfere with pedaling.

Too bad they don't make pouch cell headways..

[auraslip]

you would be getting them from ev-assemble or something, which i would avoid like the plague.. erm actually maybe we shouldn't be talking headway prices, to respect the original poster.

Yeah definitely from China. Definitely no recourse in the event of a bad cell/bms. Definitely not directly mentioning cell prices out of respect

The problem with 16ah is fitting the damn things in the frame though.
Meanwhile i can fit 20ah 10s into my frame, no problem. And the packs are so narrow that they don't interfere with pedaling.

That is the biggest issue with headway. I've gotte a 6" wide ping in my frame triangle, and it makes pedaling a pain. I'm upgrading to a 5.2" wide 72v headway pack of the 10ah cells. It should be an improvement, but we'll have to wait and see. I suppose a small 36v or 48v pack of the 16ah cells could be done lengthwise in the frame. A 72v 20ah pack would weight something like 38lbs I mean, I used to carry 40lbs of lead in my trunk bag.......and this would be in the frame.....I don't know how I feel about that

[neptronix]

That is the biggest issue with headway. I've gotte a 6" wide ping in my frame triangle, and it makes pedaling a pain. I'm upgrading to a 5.2" wide 72v headway pack of the 10ah cells. It should be an improvement, but we'll have to wait and see. I suppose a small 36v or 48v pack of the 16ah cells could be done lengthwise in the frame. A 72v 20ah pack would weight something like 38lbs I mean, I used to carry 40lbs of lead in my trunk bag.......and this would be in the frame.....I don't know how I feel about that

Geez, 6" wide? I figured those things were big, but.. damn!
My 10s 20ah pack is about 3" wide with the enclosure and weighs about 11lbs.
That's why i was willing to accept the downsides of lipo.

I can't imagine carrying anything over than 20lb, and i am sure 40lb was terrible O_O