Optimum China Batteries

Post by **woody** » Fri, 08 May 2009, 19:02

30k per day ~ 10,000km year.

The Lead-Acid batts will do their 400 cycles in about 15 months anyway

Then LiFePO4 or maybe EESTOR ?

Post by **Johny** » Fri, 08 May 2009, 19:31

Depending on side trips it should be about 250 cycles per year at around 50% DOD so I'm counting on 2 years really.

Funny that someone mentioned Firststart 18ah. They are my current favourite for purchase from an Australian distributor and my current overseas one is from Jack at Ponilion 6-DZM-20. The Firststart is 6kg and the Ponilion is 6.5kg. The Ponilion claims 23ah at the 20hr rate which is odd for a marketed 20ah battery (20ah at 2 hr rate).

Post by **Johny** » Fri, 08 May 2009, 19:34

BTW. Jack's price on 60DZM-20:
12V20Ah,VRLA battery,USD$20.74/pc
Good time to buy now with AU$ so good - shame I paid for my motor last week too.

Post by **woody** » Fri, 08 May 2009, 19:55

They look nice. 6-DZM-20 seems to be a common size. I found ABT specs. Do you have Ponilion specs?

Post by **Johny** » Fri, 08 May 2009, 20:12

Jack gave it to me as an attachment so I have uploaded it to my file area.
Ponilion 6-DZM-20

Post by **Johny** » Fri, 08 May 2009, 20:15

Ha. I forgot to mention. If you order enough (I think it's 1000) batteries you get to provide the graphic for the side of the battery - re-brand anyone? I wonder where ABT get them?

Edit: I see - they make them - sorry...

Post by **coulomb** » Sat, 09 May 2009, 03:00

Johny wrote: Need 90 Amps for 60 seconds (I'm going to regard this as continuous as it is not really "peak") but this may rise to 130 Amps once the car is on the road and I start "playing".

... So to get close to the target range, 20ah cells are required.
Lithium 20Ah cells are usually low-rate discharge - limited to 3C or 60 Amps. High rate Lithium cells are almost double the low-rate price per Ah.

...Anyway, I have a feeling that others are in the same boat as me - hemonster for one.

The 30Ah cells that weber/coulomb are pursuing may be interesting but I haven't seen a price yet.

What about Sky Energy 40 Ah SE series? They are 4C continuous, 12C pulse. 4C is 80A, pretty close to your "continuous" requirement, and there is a long way to 12 C*, so 90 A would not stress them very much. Sky energy are one of the suppliers of Thunder Sky cells, so they seem to know their stuff. Well, I guess we'll know in 4-6 weeks when the cells come through; Weber and I are now committed to these. US$1.1 per Ah via the bulk order; 27% less than the China HiPower high discharge rate cells (US$1.5 per Ah).

Granted, 40 Ah is a bit bigger than a small car would want; it was a struggle finding spaces for them in the MX-5. We've had to put 28 cells at the equivalent of "on the roof rack", but we'll have good range (perhaps 160 km) and power (100 kW).

We decided that the Thunder Sky cells were just barely OK, but it would be so nice to have another 20% power in the same sized case. (Plus the lack of heat and voltage sag that comes with that.) Low and behold, the Sky Energy cells are exactly that.

Hemonster, would these suit your application? Either of you may be able to piggy back on the bulk buy still (since we've "opened the 40 Ah door" now), but I think you'd have to be quick. I know it's a hell of a decision to make in a hurry.

* Edit: as opposed to the high discharge rate LiFePO4, which seem to have only about 17% higher peak ratings than continuous (e.g. 12C continuous, 14C peak).

Post by **Hemonster** » Sat, 09 May 2009, 15:39

coulomb wrote:
What about Sky Energy 40 Ah SE series? They are 4C continuous, 12C pulse. 4C is 80A, pretty close to your "continuous" requirement, and there is a long way to 12 C*, so 90 A would not stress them very much. Sky energy are one of the suppliers of Thunder Sky cells, so they seem to know their stuff. Well, I guess we'll know in 4-6 weeks when the cells come through; Weber and I are now committed to these. US$1.1 per Ah via the bulk order; 27% less than the China HiPower high discharge rate cells (US$1.5 per Ah).

...
Hemonster, would these suit your application? Either of you may be able to piggy back on the bulk buy still (since we've "opened the 40 Ah door" now), but I think you'd have to be quick. I know it's a hell of a decision to make in a hurry.

Indeed a quick decision, can you PN me the specifications - or email me a hemonster at gmail. 40Ah would be nice, but we're talking ~USD$10K for a 600V cell stack, - a 20Ah would be ideal for me at that price. Also isn't the weight going to be an issues for 600V, or are you guys using a lower voltage?[/quote]

Post by **coulomb** » Sat, 09 May 2009, 16:37

Hemonster wrote: Indeed a quick decision, can you PM me the specifications - or email me a hemonster at gmail. 40Ah would be nice, but we're talking ~USD$10K for a 600V cell stack, - a 20Ah would be ideal for me at that price.

Alas, there is nothing smaller than 40 Ah at this stage.

Their web page is out of date; they don't even have the info for the 40 Ah SE cells up yet. So we have to infer it from the other size cells... but the information (relative to Ah capacity) is the same up to 180 Ah.

The specs for the 180 Ah cells (the only ones with a discharge curve so far:)
http://www.skyenergy.com.cn/EnProductShow.asp?ID=4

The size of the Sky Energy SE 40 Ah cell is the exact same as the Thunder Sky 40 Ah.

The lack of real data is frustrating, and needs to be considered in the purchase decision. Also, setting the minimum discharge voltage at 2.0 V seems at least unusual. Maybe their different chemistry can handle this; maybe it just inflates the capacity figures at the expense of cell life.

This is already the second bulk buy through PoweredByDC; perhaps there will be other bulk buys in the future, when we all know a lot more about these cells.

Also isn't the weight going to be an issues for 600V, or are you guys using a lower voltage?

Yes, weight is an issue. No, we're not going with lower voltage; we're going with 208 cells, 624V nominal. That's over 300 kg for the cells alone, plus battery boxes etc. We will have to upgrade the car's differential, brakes, and suspension to cater for the additional weight. So yes, for a small car, this isn't ideal. We are lucky that bolt-in stronger differentials (with the right ratio) and brake components are available for the 1.8 L version of our 1.6 L car. Suspension components are pretty standard.

Edit: make link live

Post by **fuzzy-hair-man** » Mon, 11 May 2009, 20:25

coulomb wrote:
Hemonster wrote: Indeed a quick decision, can you PM me the specifications - or email me a hemonster at gmail. 40Ah would be nice, but we're talking ~USD$10K for a 600V cell stack, - a 20Ah would be ideal for me at that price.
Alas, there is nothing smaller than 40 Ah at this stage.

Their web page is out of date; they don't even have the info for the 40 Ah SE cells up yet. So we have to infer it from the other size cells... but the information (relative to Ah capacity) is the same up to 180 Ah.

The specs for the 180 Ah cells (the only ones with a discharge curve so far:)
http://www.skyenergy.com.cn/EnProductShow.asp?ID=4

The size of the Sky Energy SE 40 Ah cell is the exact same as the Thunder Sky 40 Ah.

The lack of real data is frustrating, and needs to be considered in the purchase decision. Also, setting the minimum discharge voltage at 2.0 V seems at least unusual. Maybe their different chemistry can handle this; maybe it just inflates the capacity figures at the expense of cell life.

There seemed to be discharge curves for all their batteries on the webpage now.

The 180AH and 100AH seem a little different to the others they list voltages of 3.6- 2.0 volts instead of 3.9 - 2.5 for the rest but they also list more cycles at 70% DOD 3000 vrs 2000 for the others, with similar improvements for 80% DOD as well.

The 90AH seems exactly the same dimensions and weight as the 100AH cells so whatever they did it seems to get more juice and more listed cycles for no weight cost according to their figures anyway.

EDIT: sorry I'm a bit slow you mean SE40 not the TK40 right?

Post by **coulomb** » Tue, 12 May 2009, 03:38

Yes, I meant SE40, to get you closer to Johny's 90 A "continuous" requirement/wish. They seem to be equal or better in all respects apart from price, and for this bulk buy, they even matched price with the Thunder Sky bulk purchase. (The SE are usually some US5c per Ah dearer normally, I believe).

The 180 Ah and 100 Ah are also SE versions. They have different chemistry, different voltage specs, and so on. The TK series are the same ones that they apparently supplied to Thunder Sky when they had more orders than they could handle. Apparently several other manufacturers performed this service at various times. Subcontracting, if you will.

Post by **bga** » Tue, 12 May 2009, 22:39

my 2c worth:

200 or 150 Wh/km. Being conservative is a good idea, pleaseant surprises are a lot better than unpleasant ones.

If twice the C rate is twice the $, more cheaper batteries may be a better solution, weight and size permitting. There may be an optimum somewhere in multiple series-parallel strings.
A Tesla has 7000+ cells: 35 strings of 200? Perhaps that's a bit too far!

Calling "Custom packs 'R' us":
A tab welder and a roll of nickel tab foil would be a useful thing. A series-parallel battery grid monstrosity would then be easy to fabricate.

Post by **Johny** » Wed, 13 May 2009, 03:56

I put in a request with another Chinese company about 48V, 15Ah packs.
I had already checked that the packs could safely be placed in series and the BMS would cope. Apparently they daisy-chain them.
Finally I asked for price - here is the reply.
------------------------------------
Dear Mr.John,

Have a great day.

Thank you for your information.
In compliance with your request, we'd like to enclose you our detailed quotation as follows:
Description: Electric car battery pack: 12pcs*48V/15Ah(in series)=576V/15Ah
                   The 12pcs of PP4815R60X will be charged independently.
Quotation:
48V/15Ah                      Unit Price: 625USD                                                                                  12 sets             Total: 7500USD
BMS                             48pcs(VMS)+12pcs(CMS)+1pcs(Relay)+1pc(RS232 Converter)+Battery control software     Total: 2970USD
C48A3                          Unit Price: 80USD                                                                                    12pcs               Total: 960USD
Freight Charge:              CIF Melbourne(26days)                                                                                                             270USD

Total: 11700USD

Pls kindly check it and feel free to contact me if there is anything i can do for you.
We need you to understand that we have cooperated with many clients in your line in European market. We hold the professional knowledge on the whole project at present. We sincerely hope to establish our good business relations with you.

Thank you for your attention and looking forward to hearing from you at your earliest convenience.

Best regards from China,

Peter

Post by **Headway** » Tue, 28 Jul 2009, 23:36

hi all of you.I'm Lorraine from China.
yes, headway 38120 have screw model we named it 38120S,it's easy to assemble with screw. and headway 38120S are known well at DIY ELECTRICE CAR AND ENDLESS SPHERE FORUM with it's high discharger rate. welcome to use our headway 38120S.

Post by **woody** » Tue, 28 Jul 2009, 23:50

Hi Lorraine,

The 38120S looks good to me, but a few things are unclear.

How long do you recommend discharging at or near the 15C limit?

I've seen a 48V 16s1p pack with a BMS:

It had a 10C discharge cut-out:, is it possible to get one with a 15C cut-out to match the battery?

What are the features of the BMS (cell balancing each cell or pairs, under-voltage cut-out, over-voltage cut out, etc.)?

What charging current can the BMS handle for a short time (e.g. 10 seconds of regenerative braking) and a long time (full charge from nearly flat)?

cheers,
Woody

Post by **Headway** » Wed, 29 Jul 2009, 17:52

Thanks for your inquiry. yes the max discharging current is 10C, but pulse discharging current can be 15C(15C is our conservative value). but in true use,just depends on your request, we can adjust it to a suitable value by BMS programme,and it will be good to our cell.

for BMS feature,I'll show you here,it's one of BMS for our 48V20AH(16S2P),continue discharging current is 30A, and pulse is 60A(of course,we can change 30A OR 60A to the value that is suitable for you)

Post by **Johny** » Wed, 29 Jul 2009, 18:07

Hi Lorraine
Headway had a 48V 20Ah pack that used 32 of the 38120S cells.
Is the pack you have described above a different pack using only 16 cells?
John

Post by **Headway** » Wed, 29 Jul 2009, 19:37

yes,we have 48V10AH(16S1P)pack with case,just use 16pcs of 38120L,38120L have no screw,jus need welding to assemble..
picture shows here.

48V20AH pack use 32pcs of 38120S or 38120L. it can be uesed on electric motorbike and electric car in parallel to be 48V100Ah,48V120Ah ans so on..picture shows here

Post by **woody** » Wed, 29 Jul 2009, 21:52

Hi Lorraine,
EV Components is where I saw the 16s1p pack - I should have included the link before.

It's great that the BMS is adjustable - is the software included?

Could you post a similar spec sheet for the 38120S & 38120P cells? We nerdy types love to see all the numbers.

I think Johny and I are interested in a similar voltage pack, around 650V nominal, 750V - 800V at max charging voltage, i.e. around 200 - 225 cells, i.e.
48V * 13 or 14
56V * 11 or 12
60V * 10 or 11
72V * 8 or 9

I think Johny wants 20Ah, I'd like 10Ah.

what other numbers of cells are your BMS available in? I've seen packs of 24,36,48,72V (8,12,16,24 cells)?

What is the PCM resistance on the specs refer to?

Have you got more details on the BMS, e.g. connection diagram or manual or even circuit diagram ?

Edit: Ah requirements

Post by **Headway** » Fri, 31 Jul 2009, 02:34

(It's great that the BMS is adjustable - is the software included? )
yes,the BMS is adjustable, not do not use software to change the continue discharging current and the max discharging current or the pulse discharging current, just add or reduce the MOSFET!

(Could you post a similar spec sheet for the 38120S & 38120P cells?)
38120L/38120S
item name     technology parameter
Normal capacity     10Ah
Normal voltage     3．2V
Max.charging current     5C(50A)
Impedance     ≤10mΩ
Max.charging voltage     3.65±0.05V
Contiune discharging current 10C(100A)
Pulse discharging current 15C(150A)
End-off voltage for discharging     2.0V
Cycle life     2000times
Operating temperature     -20~60℃
Dimension     φ38×H120(38120L)/H145(38120S) (mm)
Weight     300g/330g
Operating temperature     charge     0~45℃
     discharge     -20~60℃
Store temperature     one month     -20~45℃
     six month     -20~35℃
38120P:
item name     technology parameter
Normal capacity     10Ah
Normal voltage     3．2V
Max.charging current     5C(50A)
Impedance     ≤10mΩ
Max.charging voltage     3.65±0.05V
Contiune discharging current 15C(150A)
Pulse discharging current 20C(200A)
End-off voltage for discharging     2.0V
Cycle life     2000times
Operating temperature     -20~60℃
Dimension     φ38×H120(38120P)/H145(38120PS) (mm)
Weight     300g/330g
Operating temperature     charge     0~45℃
     discharge     -20~60℃
Store temperature     one month     -20~45℃
     six month     -20~35℃

I'll show you connection diagram , but circuit diagram ,our supplier can't show us,so I can't show you.

Post by **Johny** » Mon, 05 Oct 2009, 21:40

Hi Lorraine
Hope you are still monitoring this forum.
Can you give me dimensions on both the 60V 20AH and 48V 20AH packs please. The ones in the white boxes.

Post by **Headway** » Wed, 07 Oct 2009, 22:35

Hi Johny,
Yes,I'm here.The size of 48V20AH white ABS material box is L*W*H:285×210×140/160 (mm),height 140mm means use 38120L cell, and height 160mm means use 38120S cell.

The size of 60V20AH Al-alloy material box is L*W*H:460×160×390 (mm), but this Al-alloy material box is our newest design, only the width is solid, and the Length and the Height can be changed depends on different array. You can offer me the size you want.

Sorry,The size of 60V20AH Al-alloy material box is L*W*H:465×160×152(mm)/345*160*221(mm),

Post by **Johny** » Thu, 08 Oct 2009, 13:04

Headway wrote:.... 140mm means use 38120L cell, and height 160mm means use 38120S cell.

Sorry I have forgotten. What is the difference between the 2 cells (38120L and 38120S)?

Edit: Now I remember. The L is lug and the S is screw. Don't bother answering.

Post by **Headway** » Fri, 09 Oct 2009, 00:13

yes, Johny.please look at the picture as below:38120S&38120, The two heads of 38120S cell are with screw;38120 just means 38120L here.38120L cell without screw,the two heads are flat,need weld.They capacity is the same,both are 3.2V10AH,just different connection method.

Post by **Johny** » Fri, 09 Oct 2009, 16:04

Headway wrote:Sorry,The size of 60V20AH Al-alloy material box is L*W*H:465×160×152(mm)/345*160*221(mm),

Lorraine, are they two alternative sizes for the Al-alloy 60V 20AH?

What does the Al-alloy look like. How easy is it to mount or hold down?
Are you able to post a picture of it?