Sony VT Cells made into 75 volt 32.5 AH

[drewjet]

For my motorcycle viewtopic.php?f=10&t=3259 I wanted to go lithium to keep close to original weight. Therefore the search was on. I know A123 to be the best in small cells, and I really like the looks of the LifeBatts, however the price to get what I needed put it out of my budget. I looked at the 18650 size cells, but to get any decent power out of them was going to take way too many of them, sure it would have great range, but not what I wanted.

I found these Sony VT lithiums, 4.2 V 2.7 AH for $5.00 a piece which works out to $0.44 per WattHour. Right up my budget range. They are rated at 20C.
I ordered 225 of them, and proceeded to make them into packs. I planed on using my FMA Balance Pro chargers which can do 6 cells at up to 10 amps with built in balancing, no need for a BMS. It works out to a 18S12P arrangement gave me 75 volts and 32.5 AmpHours. I decided form factor would be best of 3 sets of 6S12P put in Series.

Below are a few pictures to show how I made it. Ah the joy of soldering up 216 cells. It took me about a week.

[TylerDurden]

Any more info on those cells? Spec sheet, link, etc...?

[Ypedal]

Cool !!

It's Xysterrific ! *( where has that guy gone ??? )

Those look similar to the Makita cells, i have a pile i need to work on next week, keep up the good work !

[drewjet]

I found him on ebay from a friend who bought his cells and said they seemed to be as claimed. There is a reference to the Sony spec sheet on ebay.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0177299386

[evmotorcycle.org]

Nice one DrewJet!

Have you tested this on the bike yet?? how many miles you reckon it will go for?

What's the situation with charging? Do you have multiple chargers with this setup? Can you post the overall dimensions and weight of the complete pack when you are done.

Cheers

Andy.

[drewjet]

I have had a couple of test runs so far. About 6.5 miles each time and put back about 6.5 amp hours. I don't have an amp meter that will go high enough to read what current I am drawing, so for now I have to rely on my chargers info. I have 32 amp hours available and by trying to stay under 80% DOD I should get about 26 miles range. Time will tell me if I am correct.

I see a high volt version of the cycle analyst in my future.

[kbarrett]

That CA has become a must have if you start to get serious about this stuff ...

[evmotorcycle.org]

What size is the overall pack? Is it really large? Also what weight do you reckon the pack is?

Andy.

[TylerDurden]

December 9, 2004

Announcement of New Lithium Ion Batteries, Realizing Industry's Highest Level of Energy Density
- High-power output cylindrical lithium ion battery fit for high-power supply also announced -

Sony Corporation announces the new line-up of lithium ion batteries, with industry's highest level of energy density, responding to the needs for high capacity and large current in secondary batteries for mobile products. Shipment will start from December 2004 onwards.

Photo : (from left to right) VT Cell, G8, A8, S Pack

ion01.jpg

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*The capacity depends on the requested size of the battery.

Accomplishment of higher capacities in secondary batteries continue to be required from the market, due to higher performance and enhanced features in mobile products such as note PCs, digital video cameras and mobile phones. At Sony, commercialization of the world's first high power density, small size, light weight and long life lithium ion battery was announced in 1991 and, in 1999, lithium ion polymer battery with flexibility in shape and enhanced safety was announced, further responding to such needs. As a result, the world-wide market size of lithium ion batteries (including lithium ion polymer batteries) has grown to a market of 1.2 Billion units.

In the cylindrical lithium ion battery and the lithium ion polymer battery announced today, industry's highest level of energy density has been accomplished, enabling long hours of operation in mobile products.
In the cylindrical lithium ion battery, <G8 Series>, in a cylindrical standard size of diameter 18mm and height of 65mm standard size, maintaining the same level of charging/discharging characteristics, industry's highest level of high capacity with 2550mAh (which is 6% increase from the conventional battery) has been accomplished, further adding power (i.e. "Stamina") to the operation of note PCs and digital video cameras requiring high power.
In the Lithium ion polymer battery, <A8 series>, characteristics such as high freedom in the ease of product design (in which the battery is to be used) and high level of safety from the polymer construction have been maintained and 830mAh (9%increase from Sony's conventional model, with the same size) have been realized, supporting long hours of operation in small portable products such as mobile phones.

In addition, targeting the expansion of business in the mobile phone market as well as expansion of lithium ion battery market, new models, the S Pack and V Cell, VT Cell Series are introduced.
S Pack is a lithium ion polymer battery pack dedicated to mobile phone use, where high efficiency is realized in a limited spacing from the convergence of the two technologies, lithium ion polymer and packaging.
In the V Cell and VT Cell Series, the challenge of large current discharge has been accomplished, enabling use of lithium ion batteries in power tools, cleaners, motor assisted bicycle where lithium ion batteries were not used in the past, leading to market expansion of high-power cylindrical lithium ion batteries.

Sony will continue making progress on technology development of batteries with respect to various aspects, such as safety, reliability in high performance, high capacity and consciousness to the environment, and by introducing new lithium ion battery line-up Sony will target to expand its battery business as well as the market.


• Main Characteristics of industry's maximum capacity Cylindrical Lithium Ion (G8 Series)
From the change to 'Can' and the cathode structure, high level of charging has become possible, leading to 6% increase* in capacity compared to conventional battery. Also, due to the fact that the change is focused on structural changes, the curve of discharge is negligible compared to the conventional cell, enabling usage of the in the same battery pack as the conventional one.
*2550mAH (comparison with conventional cell:2400mAH)


• Main Characteristics of industry's maximum capacity Lithium Ion Polymer (A8 Series)
By slimming of the external structure, 9% increase of the capacity has been accomplished, compared to the conventional battery. As it is of a higher capacity when compared to a same size rectangular lithium ion battery, it is appropriate for new generation mobile phones for multimedia purposes.
*830mAh (comparison with conventional same size battery : 760mAh)


• Main Characteristics of New Concept Battery Pack (S Pack)
Utilizing the characteristics of lithium ion batteries (no leakage, less swelling), the battery pack has been simplified, reducing the number of parts. Also, by using a stronger external film as it is as the exterior pack, maximum space efficiency has been achieved in the final products, which is the battery pack.


• High power Cylindrical Lithium Ion battery (V Cell, VT Cell Series)
By using Nickel/Manganese mixture in the positive electrode, stability in high temperature conditions have been achieved, also achieving safe usage with high level of current, this being the characteristics of V/VT series. By the combination with high-voltage, which is the characteristics of lithium ion batteries, usage in the high-power output application field (such as power tools, cleaners, motor assisted bicycles) will be ideal, where conventionally Nickel-Cadmium, Nickel-Hydrogen batteries were used. In the 18650V cell, maximum output of 10A, and in the 6650VT cell, maximum output of 50A have been achieved.

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http://www.sony.net/SonyInfo/News/Press ... 2/04-060E/

pdf2310[2].pdf

pdf file from ebay listing

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[drewjet]

Pack size is 3.5" X 6.5" X 13"
19 Pounds

[Doctorbass]

For my motorcycle viewtopic.php?f=10&t=3259 I wanted to go lithium to keep close to original weight. Therefore the search was on. I know A123 to be the best in small cells, and I really like the looks of the LifeBatts, however the price to get what I needed put it out of my budget. I looked at the 18650 size cells, but to get any decent power out of them was going to take way too many of them, sure it would have great range, but not what I wanted.

I found these Sony VT lithiums, 4.2 V 2.7 AH for $5.00 a piece which works out to $0.44 per WattHour. Right up my budget range. They are rated at 20C.
I ordered 225 of them, and proceeded to make them into packs. I planed on using my FMA Balance Pro chargers which can do 6 cells at up to 10 amps with built in balancing, no need for a BMS. It works out to a 18S12P arrangement gave me 75 volts and 32.5 AmpHours. I decided form factor would be best of 3 sets of 6S12P put in Series.

Below are a few pictures to show how I made it. Ah the joy of soldering up 216 cells. It took me about a week.

Ah haaa!

great project too!

I have the same konion cells (li-Mn) but in thw 18650V format... 10C 1500mAh 3.7V, safe.. etc

http://endless-sphere.com/forums/viewtopic.php?f=14&t=2764&p=49919#p49919

They are a great alternative to the A123 about safe and powerfull cells!

I also have the VT serie from the 1.5Ah Makita pack.. (see pic)

all the V and VT serie cell that i have in the Makita pack HAVE NO BMS THAT BALANCE THE CELL INSIDE!!

Doc

[Doctorbass]

There is a debate on the Tesla roadster forum about what kind of battery they use (the 6831 cells)

AND finally, they conclude that it's the US18650V Li-Mn cells!!!

Bike : 44g x 360= around 30lbs... for a 80lbs bike with 5KW motor
-batt weight vs car weight=0.375
-power vs weight=62W/lb .... with driver= 22W/lbs

Tesla: 44g x 6831= around 662lb for a 2500lbs car with 185kW motor =
-batt weight vs car weight=.265
-power vs weight=74W/lb

humm... that's the reason why my bike dont reach the same acceleration slope of 0-60mph in 4sec I would need 15kW to reach the same ratio of a tesla....


now let's return to your great project

[drewjet]

I had some spare time while waiting for my controller to come back and add a little bling

Drew

[Doctorbass]

!

[Eric G]

Absolutely Great
Inovative packaging

Eric

[johnws6]

Anyone know of a place that is selling this similar cell? I've checked on ebay but haven't found them.

[ejonesss]

are these normal lithium ion's or lifepo4?

normal lithium ion's are the first gens that are known to require careful charging to prevent explosion and fire. (remember the battery recalls?

[pwbset]

These are LiMn. Comparably as safe as LiFe.

[drewjet]

Very safe cells and I charge using a high end balance charger that brings each bank of cells up to an identical 4.2 volts.

[pgt400]

DJ, how did these cells hold up? Last report from you I think you stated the capacity was way down?

Thanks,

Phil

[oofnik]

These cells appear impossible to find any more.

[drewjet]

I thought capacity was way down, but I was wrong.

What actually happened is on bank of cells went to 0 volts. I now efectively have 17 series instead of 18. Not a big deal, only lost about 3 MPH. ( I haven't taken the packs apart to investigate yet). What happened, and I didn't realize till just a few weeks ago, is that I was hitting the LVC on my Kelly controller. It doesn't cut out, but instead, backs the power down. So I thought I was running out of range, but to my delight just need to change my LVC.

1400 miles and counting.

[pgt400]

My Kelly cuts off at low voltage. After 18 miles, I have to keep my accel current under 150 amps.

[drewjet]

could be the difference between programming of brushed and brushless

[pgt400]

So sounds like the only way to get these cells is buy Makita packs?