RealForce LiFePO4 packs (10ah 24-36v)

I recently requested a price quote from a company off globalspec, asking for a quote on 2-10 quantities of 10ah packs. I'm sure they could build whatever we would want. Here is the email they sent back to me (sorry about the freaky formatting...copy and paste you know...):

[pre]Thank you for your interest in RealForce LiFePO4 E-bike batteries. My name is Frank Foo.
I am giving you E-bike battery price quotations on both 24V 10Ah and 36V 10Ah .

Pricing based on Two (2) Unit Ten (10) Unit
RFE-8F10 LiFePO4 E-bike Battery 24V 10Ah 142 per 138 per
BMS (Battery Management System) included included
Battery Charger included included
Aluminium outer case for battery included included
____________________________________________________________________________
TOTAL 142 per 138 per
DIMENSIONS: 87*87*390mm
WEIGHT: approx. g.w.t 4.0 kg per


Pricing based on Two (2) Unit Ten (10) Unit
RFE-12F10 LiFePO4 E-bike Battery 36V 10Ah 198 per 190 per
BMS (Battery Management System) included included
Battery Charger included included
Aluminium outer case for battery included included

____________________________________________________________________________
TOTAL 198 per 190 per

DIMENSIONS: 77*110*395mm
WEIGHT: approx. g.w.t 6.0 kg per
ALL PRICE QUOTATIONS ARE IN US DOLLARS.
FOB SHENZHEN, CHINA (ALL FREIGHT CHARGES AT CUSTOMERS' EXPENSE).
PRICES QUOTED GOOD FOR NINETY (90) DAYS 17.11.2009 ~ 17.02.2010.

The 10Ah is more than adequate for biking enthusiasts who have no need for all
battery powered motion, but rather an occasional lift instead. The 20Ah and 30Ah batteries
are heavier, bulkier and more expensive, geared for transportation purposes.
If you have questions, any specific requirement needs or wish to discuss other purchase order
volumes, please do not hesitate to contact me. Thank you for your consideration.

Sincerely,

Frank Foo
REALFORCE ENTERPRISES (lithium batteries, PV, et al.)
XUEWEI ROAD, REALFORCE INDUSTRIAL PARK,
WEISHAN ECONOMIC DEVELOPMENT ZONE,
JINING CITY, SHANDONG PROVINCE, CHINA 277600

Office： +86-537-8699997 x8819
Fax： +86-537-8699916
Mobile: +86-15006788505
Email: sales_ua@realforce.com.cn
Web： http://www.realforce.com.cn[/pre]

Here is the CR4 entry: http://www.globalspec.com/Supplier/Profile?vid=371803&frmtrk=search-hc

And the website is listed there. Seems as though they do a lot of volume, so maybe they can undercut prices on some of the other suppliers we have. Just thought I would stick this out there for those of you who actually have money to buy batteries...

Here's another response with a quote for prismatic 20ah and 50ah cells.

Thank you for your interest in RealForce lithium-ion battery products. My name is Frank Foo.

Here are 2 price quotations for prismatic battery cells - 20Ah and 50Ah - per your request.


Twenty (20) units MOQ

RFE-F20 3.2V 20Ah LiFePO4 Prismatic Battery Cells $25 per

DIMENSIONS: 13*150*225mm per

WEIGHT: approx. g.w.t. 0.85 kg per


Twenty (20) units MOQ

RFE-F50 3.2V 50Ah LiFePO4 Prismatic Battery Cells $63 per

DIMENSIONS: 12*235*248 mm per

WEIGHT: approx. g.w.t. 1.4 kg per


ALL PRICE QUOTATIONS ARE IN US DOLLARS

FOB SHENZHEN, CHINA (ALL FREIGHT CHARGES AT CUSTOMERS' EXPENSE)

PRICE QUOTATIONS GOOD FOR NINETY (90) DAYS 16.12.2009 ~ 16.03.2010


RealForce can deliver the battery pack usually 30 days after receiving bank wire payment.

Dylan, if you have questions or any specific requirement needs, please do not hesitate

to contact me. Thank you for your consideration.



Sincerely,

Frank Foo

Click to expand...

Seems like a darn good price for a 20ah prismatic cell. I don't know what the shipping would be...would have to ask them to do a mock order to find out. I asked for a quote on smaller quantities but they didn't provide one so maybe they don't offer shipments of less than 20 cells.

His quotation states, "Twenty (20) units MOQ ." MOQ = Minimum Order Quantity; that's probably why you did not receive a response for a lower number.

Do you have any information about the C rate of these packs? They all look like 2C except the tool packs here. which are 10C.

Eric S.

Yeah that would be the one major drawback is the discharge rate. However who among us uses more than 40 amps on a regular basis? (The prismatic cells are 2C) I don't ever use more than 30...but then again I am on a 24v system. I didn't pay much attention to MOQ but the notion did cross my mind that he had a min. order quantity. Anyways its there for anyone who's interested.

The internal resistance of their better prismatic 10Ah cell is is 16 miliohm wich is a bit high.

The BMI, PSI, Headway are all under 8 miliohm.

Conclusion.. You get what you pay for

Lower cost... lower performances

but i admit that for normal people that never exceed 40A on their system, this is a great find :wink:

Doc

Doctorbass said:

The internal resistance of their better prismatic 10Ah cell is is 16 miliohm wich is a bit high.

The BMI, PSI, Headway are all under 8 miliohm.

Conclusion.. You get what you pay for

Lower cost... lower performances

but i admit that for normal people that never exceed 40A on their system, this is a great find :wink:

Doc

Click to expand...

I think Doc was reading my mind. He said exactly what I was going to say!
You really do only get what you pay for. I suggest ordering a cell for testing since you may well find that the performance specifications are not the truth. For example the manufacturer might claim the pack is 30Ah but if you actually measure its capacity you more than likely will find it may only measure out at 25Ah or less. Also Doc is right about the internal impedance. 16 milliohms is quite high. Under 10 ohms is better and if you can get under 4 milliohms as in the below pic you are doing brilliantly. Of course the best way to determine this is by measuring a test cell. So before you potentially lose your hard earned dollars down the drain ask if you can buy a cell for testing.
Best of luck!
View attachment BMI Cell Impedance Test.JPG

BMI said:

Doctorbass said:

The internal resistance of their better prismatic 10Ah cell is is 16 miliohm wich is a bit high.

The BMI, PSI, Headway are all under 8 miliohm.

Conclusion.. You get what you pay for

Lower cost... lower performances

but i admit that for normal people that never exceed 40A on their system, this is a great find :wink:

Doc

Click to expand...

I think Doc was reading my mind. He said exactly what I was going to say!
You really do only get what you pay for. I suggest ordering a cell for testing since you may well find that the performance specifications are not the truth. For example the manufacturer might claim the pack is 30Ah but if you actually measure its capacity you more than likely will find it may only measure out at 25Ah or less. Also Doc is right about the internal impedance. 16 milliohms is quite high. Under 10 ohms is better and if you can get under 4 milliohms as in the below pic you are doing brilliantly. Of course the best way to determine this is by measuring a test cell. So before you potentially lose your hard earned dollars down the drain ask if you can buy a cell for testing.
Best of luck!

Click to expand...

Is your impedanse tester protected against reverse polarity? I just blown 2 unit from different brand... They are so fragile!

If so I might buy that KT97.

BMI, You should edit your reply for 10 miliohm instead of 10 ohms :wink:

Doc

Doctorbass said:

BMI said:

Doctorbass said:

The internal resistance of their better prismatic 10Ah cell is is 16 miliohm wich is a bit high.

The BMI, PSI, Headway are all under 8 miliohm.

Conclusion.. You get what you pay for

Lower cost... lower performances

but i admit that for normal people that never exceed 40A on their system, this is a great find :wink:

Doc

Click to expand...

I think Doc was reading my mind. He said exactly what I was going to say!
You really do only get what you pay for. I suggest ordering a cell for testing since you may well find that the performance specifications are not the truth. For example the manufacturer might claim the pack is 30Ah but if you actually measure its capacity you more than likely will find it may only measure out at 25Ah or less. Also Doc is right about the internal impedance. 16 milliohms is quite high. Under 10 ohms is better and if you can get under 4 milliohms as in the below pic you are doing brilliantly. Of course the best way to determine this is by measuring a test cell. So before you potentially lose your hard earned dollars down the drain ask if you can buy a cell for testing.
Best of luck!

Click to expand...

Is your impedanse tester protected against reverse polarity? I just blown 2 unit from different brand... They are so fragile!

If so I might buy that KT97.

BMI, You should edit your reply for 10 miliohm instead of 10 ohms :wink:

Doc

Click to expand...

Whoops....typo error! Thanks Doc. Yes should read 10 milliohms.

Yes all the cheap Chinese battery impedance meters are very sensitive and are easily damaged if you don't connect everything correctly. I have only blown one before this one so you are ahead of me by one!
If you can afford the very best (over $1000) meter buy a Hioki 3555....simply brilliant!

Doctorbass said:

The internal resistance of their better prismatic 10Ah cell is is 16 miliohm wich is a bit high.

The BMI, PSI, Headway are all under 8 miliohm.

Conclusion.. You get what you pay for

Lower cost... lower performances

but i admit that for normal people that never exceed 40A on their system, this is a great find :wink:

Doc

Click to expand...

That is true if you are looking at the 10ah cells. I'm looking at the 20ah cells which seem to have an internal resistance of 8 m-ohms for the 20 and 3 m-ohms for the 50ah cells. That doesn't seem bad to me.