Headway or A123?

Hi there!

this is/was my scooter
http://endless-sphere.com/forums/viewtopic.php?f=2&t=49287

And I got me another (newer model) G-Bike POS for $175 after mine failed
http://endless-sphere.com/forums/viewtopic.php?t=51841

They can be had really cheap, they fail quite often because of cheap built/material.
It has 4 x 12V 20Ah SLA batteries and a 750W motor.
Controller etc can be seen on the first link.

Now that I have 2 (the first one is for spare parts) I feel comfortable enough to invest in better batteries.

After reading through this domain and it's endless source of information, I am more confused than before.

I would have loved to get something like this and be done with it:
http://www.ebay.com/itm/48V-20AH-LiFePo4-Battery-Lithium-Electric-Bicycle-Scooter-E-Bike-Rechargeable-/290962283266

However, reading the horror stories about used or knock off cells with no warranty or support, prohibitive expensive return shipping costs etc, I'd rather go the safe route.

So here it goes:
For batteries (I would need 15 to 17 LiFePos, right?) I found out that the price should be roughly $2 per Ah (per cell).

So I was looking at 10Ah (which is how long SLA's will last):
http://www.buya123batteries.com/ANR26650M1A_p/300001-001bb.htm
and
http://www.all-battery.com/Tenergy3.2V10Ah38120SLiFePO4EnergyCellRechargeableBattery-30074.aspx

Which would you recommend?

For BMS (some have MITSUMI MM3474 series, some are analog, which is better?) I was considering

http://www.ebay.com/itm/16S-48V-30A-60A-LiFePO4-Battery-Pack-BMS-System-eBike-Electric-Bicycle-/290959522828
or
http://bestechpower.com/512v16spcmbmspcbforlifepo4batterypack/PCB-D167.html

Again, which would you recommend or do you have any other trusted sources you could recommend?

Totally appreciated!
Power

For many of us, there is nothing better than A123 nanophosphate LiFePO4, but we're a highly biased clan. Measure life-time cost per amp-hour to get a true comparison. 2000+ cycles for A123, minium, for genuine cells, properly handled. Best!

I read many posts about these, but considering that I can only afford B grade A123s, and considerimg that I would need to wire 4x A123s in paralell (vs 1 Tenergy) , and seeing that the technical specs are quite similar, would the board bias still trump the Tenergys?

That blue cylindrical cell is a Headway cell..

also, fyi, Tenergy is not the same as Turnigy ... very BIG difference. :wink:

Wow, thanks for catching that!
I tought these were Turnigy batteries!
Had read about them like about A123.

Now following Turnigy leads to hobbyking, and from what i read here, I'd rather not.

So the question needs to be rephrased to "Headway or A123?"

So how do they match up?

Thanks!

legitimate a123 for sure
headway = crap

I bought 16 of those Tenergy 10Ah cells back in 2013 and have had no troubles with them at all. I haven't pushed them to the limit by any means, typically 20-25A continuous. They all say Tenergy on them, I don't know if they're truly headway or just look alike. As a side note, they were all serialized and date stamped with a sheet specifying internal impedance of each individual cell. Not necessary but a nice touch.

davec said:

legitimate a123 for sure
headway = crap

Click to expand...

I disagree with this, unless you have something more to add such as real data.

My suggestion in nether. Depending on space I would get nissan leaf cells (modules), 7.4V 60ah at 125usd per module or chevrolet volt battery pack at 245usd per kilowatt (40ah battery, few series configurations available) if I remember correctly. No wanking about with terminations etc

Real-A123.

While I remain a proponent of A123, I recently purchased some Headway cells, for my Nephew, who is making his own eBike now. Its not just chemistry, manufacturer, format and so forth. Its also about how easy it is to source and make a fully operational battery pack.

First there are a variety of sourcing opportunities for the cells, among them:
http://www.headway-headquarters.com/40152s-15ah-headway-cell/
http://osn.en.alibaba.com/product/946152087-220710673/3_2v_15ah_lifepo4_battery_cell.html
http://www.greenbikekit.com/battery-cell/40152-headway-cell.html
https://bmsbattery.com/ebike-batter...lifepo4-cylindrical-battery-cell-battery.html
http://www.aliexpress.com/wholesale...0150414103657&SearchText=headway+lifepo4+15ah
Cells need to be widely available, in use, easy to buy with a healthy competitive marketplace. Headway meets this criteria. All of the above sourcing opportunities allow PayPal and CreditCard purchases as well.

Second, I like the relative ease of assembling these into a pack. They have a nut & bolt assembly at the cap ends. So no soldering or spot welding needed. Ease of assembly also means ease disassembly, when replacing a dead cell and so forth.

Third is cost. The Headway cells are a fraction of A123, yet still have the promise of 2000+ charge/discharge cycles.

A123 does look good on paper, but who really has data to show 2000+ cycles? I commute daily and to get 2000 cycles, you would have to cycle the batteries every work day for 7-8 years. I commute to work daily and have only been doing it for 3 years plus. My lipos have gone through about 500-600 cycles. I take care of them and that is incredible for lipos. They're still going strong and kicking. Some have died off at around 300 cycles. However, they are 1/3 the cost of genuine A123. That means the genuine A123 pack must have a minimum of 1000 cycles to compete with my lipos in terms of cost.

Without real world data, I would go the cheaper route. A123 genuine cells are nearly twice as much as generic packs. Will they last twice as long as non-genuine packs? I doubt it. The non-genuine packs and Headway cells boast great specs on paper. Even if they last half as long, you will have gotten your money's worth.

My headway cells have gotten me over 7000 miles and are at about 85% of original capacity. I have crashed my bike multiple times and the cells have not shown a problem. They have a lower c rating then on paper aprox 2c vs what ever they say on paper so be sure to have enough ah for your build.

Headways, from my real world experience are very dependable, robust and long lasting if a bit on the low c side.

agniusm said:

My suggestion in nether. Depending on space I would get nissan leaf cells (modules), 7.4V 60ah at 125usd per module or chevrolet volt battery pack at 245usd per kilowatt (40ah battery, few series configurations available) if I remember correctly. No wanking about with terminations etc

Click to expand...

+1

2015 and up LEAF cells are better than A123's best, less than half the price, and you just bolt up a few jumpers and your pack is done.

Just for hell-of-it, I searched Amazon for LiFePO4, to see what might pop-up, and sure enough: Tenergy SideKick STORM Weather Resistant Portable LiFePO4 13600mah Power Bank and Car Jump Starter. I'm getting me one of these for portable power. But also thinking 4x is a 48V 13.6ah pack, up to 400amp delivery. Power protection built-in. Charger included with the nicety of parallel 12V charging and redundancy of parts. Pack dies - its in 12V increments. Rewire to 36V, get back on the road, order up a replacement.

arkmundi said:

Just for hell-of-it, I searched Amazon for LiFePO4, to see what might pop-up, and sure enough: Tenergy SideKick STORM Weather Resistant Portable LiFePO4 13600mah Power Bank and Car Jump Starter. I'm getting me one of these for portable power. But also thinking 4x is a 48V 13.6ah pack, up to 400amp delivery. Power protection built-in. Charger included with the nicety of parallel 12V charging and redundancy of parts. Pack dies - its in 12V increments. Rewire to 36V, get back on the road, order up a replacement.

Click to expand...

Specifications:
Model No: 51095
Battery: LiFePO4
Capacity: 13600mah (enough to Jump Start a Car more than 30 times)
Output: 19V/ 16V/ 12V 3.5A
USB Output: 5V 2A
Charge Mode: CC/CA 15V 1A
Starting Current: >200A
Peak Current: 400A (<3S) Operating Temperature: -20°C~85°C
Power Bank Dimension: 6.5 x 3.1 x 1.6 in (165 x 79 x 40mm)
Packaging Dimension: 9.4 x 7.7 x 2.6 in (240 x 195 x 67mm)
Weight: 1 lb (Power Bank only) 2 lb 8.1oz (with packaging and accessories)


Wow! They either have cracked the world record for LiFe energy density, or the specs are as realistic as the last "20,000mAh" power bank I tested that did an actual 4,600mAh total measured.

Who is the forum guy with the equipment to do capacity checking? I could buy, have shipped there for testing, then to me. Would be good to know whether this NOT-truth in advertising, or stands up to the specs & test. I'm getting just one for the moment, because whether or not, would love to have a way to USB charge stuff up.

arkmundi said:

Who is the forum guy with the equipment to do capacity checking? I could buy, have shipped there for testing, then to me. Would be good to know whether this NOT-truth in advertising, or stands up to the specs & test. I'm getting just one for the moment, because whether or not, would love to have a way to USB charge stuff up.

Click to expand...

Well, your first pass sanity test on its weight tells you either the weight or capacity is wrong in a big way.

liveforphysics said:

2015 and up LEAF cells are better than A123's best, less than half the price, and you just bolt up a few jumpers and your pack is done.

Click to expand...

Luke,

How do I know if the cells are 2015 and up (lizard battery)?
Im seriously tempted to buy some and do a "portable" powerbank.

liveforphysics said:

Well, your first pass sanity test on its weight tells you either the weight or capacity is wrong in a big way.

Click to expand...

I appreciate how you're dissecting this. But, I don't discount the possibility of new cost, weight, power-density barriers being broken, which is why I continue to research the question.

Specifications:
Model No: 51095
Battery: LiFePO4
Capacity: 13600mah (enough to Jump Start a Car more than 30 times)
Output: 19V/ 16V/ 12V 3.5A
USB Output: 5V 2A
Charge Mode: CC/CA 15V 1A
Starting Current: >200A
Peak Current: 400A (<3S) Operating Temperature: -20°C~85°C
Power Bank Dimension: 6.5 x 3.1 x 1.6 in (165 x 79 x 40mm)
Packaging Dimension: 9.4 x 7.7 x 2.6 in (240 x 195 x 67mm)
Weight: 1 lb (Power Bank only) 2 lb 8.1oz (with packaging and accessories)

These specs seem too good to be true. I've been buying, searching, testing lipos and lifepo4s for the past 10+ years. I've never seen lifepo4 cells producing this much current. Even the best lipos only boast 200amps continuous current and they are the amp discharge champ. Seems too good to be true. And the above shows 400a (<3S). That doesn't make sense. 3S on 13.6 amps equates to about 40amps. Is that a typo? If it's a typo, then 40s is too good to be true. The best lipos can do that, but never seen lifepo4 boast those amp discharge numbers and not at this price point.

Has anyone jump started a car with this and do it multiple times on a single charge? If so, then would be quite a performer.

I wanted to find some info on real world testing of the Nissan Leaf battery and found this article:

http://insideevs.com/long-term-review-nissan-leaf/

Scroll to the bottom regarding battery life. Keep in mind, this test is on a car about 2 years old, so older battery production of the battery chemistry. With that said, not too shabby results. Only 5% capacity loss from 20k miles of driving. Of course, the testers did baby the batteries during charge and storage. Other owners had less than optimum results.

Look closely before you buy! So its not 13.6ah, but 3.4ah. Boy was that sneaky.

Are there any long term cycle tests for the headways, besides the headways own sheet?

I recently saw such testing for A123 and it was interesting.
It was a russian site, dont remeber exactly.
They used the test cells only from 30-50% and the cells last multiple thousands cycles (10000).

Found the link again, i think its worthy a new thread......
http://komar.bitcheese.net/ru/о-ресурсе-LiFePO4-аккумуляторов-A123

I didnt read all but it seems the test came from sweden.

ziltoid81 said:

Are there any long term cycle tests for the headways, besides the headways own sheet?

I recently saw such testing for A123 and it was interesting.
It was a russian site, dont remeber exactly.
They used the test cells only from 30-50% and the cells last multiple thousands cycles (10000).

Found the link again, i think its worthy a new thread......
http://komar.bitcheese.net/ru/о-ресурсе-LiFePO4-аккумуляторов-A123

I didnt read all but it seems the test came from sweden.

Click to expand...

I don't see any reason to doubt Headway's own datasheet on cycle life. It may not be perfect, but it's useful to compare with other types. Even if you don't get a full 2000 cycles, say 1500, is that a big deal? Other factors besides depth of discharge (temperature, calendar life, charge/discharge rate, etc) will affect lifetime as well.

The russian site is interesting, looks like for "Cycle C" they were discharging at about 4C (headway's spec is 1C) and still got around 1500 cycles before going below 80% capacity. "Cycle E" looks to be around 1C discharge and ~2C charge rate, and it looks like they got around 2800 cycles before dropping below 80% capacity. They call it a bad result, but it seems pretty good to me.

http://www.amazon.com/Spirit-A8-Emergency-Ultra-bright-Cellphone/dp/B00KBINF7G/ref=pd_sim_sbs_cps_1?ie=UTF8&refRID=18XFTQADF5KXK0C82J9E

Similar boasting 18000mAh.