I agree 'Kokam' look nice but are very expensive. I would love a 20ah boost set for my Insight. Other Li-Po flat cell manufacturers may also be worth looking at.
I would also consider buying further cells from TS, the newer models give much better performance at low temps. I am still using my original Sept 2003 set of 30 x 200ah TS cells in my EV!
Somone had to take the risk with all these untried products, I and several other UK members did over 4 years ago. I gambled £4500 then and am still in the game Some were pleased some disapointed, the bigger cells def seemed better than the smaller ones.
Battery technology goes marching on I'm sure we haven't seen anything yet folks!
Tempting fate
- retepsnikrep
- Posts: 1387
- Joined: Sat May 26, 2007 4:50 pm
- Location: North Yorkshire England
- Contact:
Thundersky cells with Cobalt chemistry have indeed been well proven. However the Manganese cells have had internal corrosion problems, particularly if layed on their side. They can die in just months in some cases. Aparently the Iron Phosphate 'power' cells also have the same problem, to what degree I don't know.
The company got a very bad reputation in the US early on for shipping defective cells and doing nothing about it, but it isn't in theory the same company any more, but we have defective cells again and the same bad attitude.
Now I hear that they are increasingly reluctant to sell in small quantaties and are going to be phasing out the Cobalt cells! My peak power requirements rule out the Cobalt cells in any case.
Doing business with China is often difficult and the Lithium cell market is in a period of rapid change, development and expansion. There's no effective patent or design protection system in China and products can be copies of copies of copies. There are dozens of factories, often with several brand names, dozens of re-branders and/or middlemen, and probably hundreds of sellers. You've got to be dealing with the factory or you've got little chance of getting the same thing twice.
I'm not against Chinese products and I've recently bought both a TIG welder and a Plasma cutter (via ebay outlets). In the case of the TIG I researched for over a year as to who was worth dealing with, but I'm very happy with the functionality and the build quality.
Kokam had a proven product in one application area, which they developed into others. Their prices have come down a lot and they're looking like a very viable option.
The company got a very bad reputation in the US early on for shipping defective cells and doing nothing about it, but it isn't in theory the same company any more, but we have defective cells again and the same bad attitude.
Now I hear that they are increasingly reluctant to sell in small quantaties and are going to be phasing out the Cobalt cells! My peak power requirements rule out the Cobalt cells in any case.
Doing business with China is often difficult and the Lithium cell market is in a period of rapid change, development and expansion. There's no effective patent or design protection system in China and products can be copies of copies of copies. There are dozens of factories, often with several brand names, dozens of re-branders and/or middlemen, and probably hundreds of sellers. You've got to be dealing with the factory or you've got little chance of getting the same thing twice.
I'm not against Chinese products and I've recently bought both a TIG welder and a Plasma cutter (via ebay outlets). In the case of the TIG I researched for over a year as to who was worth dealing with, but I'm very happy with the functionality and the build quality.
Kokam had a proven product in one application area, which they developed into others. Their prices have come down a lot and they're looking like a very viable option.
Paul
http://www.compton.vispa.com/scirocco/
http://www.morini-mania.co.uk
http://www.compton.vispa.com/the_named
http://www.compton.vispa.com/scirocco/
http://www.morini-mania.co.uk
http://www.compton.vispa.com/the_named
-
- Posts: 79
- Joined: Mon Jun 11, 2007 9:35 am
- Location: Herts, UK
Lithium Battery - Group Buy
Hi Chris,
I am looking for a lithium based battery solution for my up-coming EV conversion project. In fact it is the battery pack I am waiting for before I can start having sourced all but some minor bits up to now. I was going to use lead-acid but with the recent hike in prices if you factor in life of the battery and weight/power density issues, lithium is by far the more economic/sensible choice.
So I'm interested.
Nice blog BTW - well worth a look for anyone who hasn't as yet.
Regards, Martin Winlow.
I am looking for a lithium based battery solution for my up-coming EV conversion project. In fact it is the battery pack I am waiting for before I can start having sourced all but some minor bits up to now. I was going to use lead-acid but with the recent hike in prices if you factor in life of the battery and weight/power density issues, lithium is by far the more economic/sensible choice.
So I'm interested.
Nice blog BTW - well worth a look for anyone who hasn't as yet.
Regards, Martin Winlow.
-
- Posts: 244
- Joined: Tue Dec 11, 2007 11:26 pm
Hi Martin.
Two recent quotes, at either extreme look like this.
>>>>>>>>
I've discussed about the parameters you sent to me. Accordingly, I'd like to recommend you our EP60Ah battery. I suggest two EP60Ah batteries in parallel connection to reach 120Ah. This model of EP 60Ah can discharge at 1C-2C at normal working condition and 5C at peak current. This way, they can totally meet your request on running current and peak current without any damage to the batteries. Also, according to your proposed voltage of 100-140V, it requires 33 batteries of 120Ah in series connection. Thus, you need totally 66pcs EP60Ah batteries.
And the FOB price for a single EP60 is USD 148.97. The total price for a pack without BMS and charger is USD 9831.73. Additionally, do you need BMS and charger from us? If you do, I will quote for you next time, ok?
>>>>>>>>>>>>
And this next one looks far too light to be true !
>>>>>>>>>>>>>>>
we have calculate the unit price for u:21945USD,the technic preference list as below:
1. Nominated Capacity:100 Ah
2. Output voltage:100V-140V
3. Output Current:800A max
4. The power Dimensions:450mm×400mm×350mm
5. Weight:65kg
6. Package:air-shipped box with wheel
>>>>>>>>>>>>>>
One company came up with a 48V 100Ah pack of LiFePo for £595 but asked for more details before they could quote more specifically, I bet it climbs up a bit but I'll let you know, I actually think they made a mistake with a decimal point !
I should get some more work done on the battery balancer on my blog later this week. I have several reports to submit for my exams tomorrow which have been holding me up. The only thing I have left to do is write the charging algorithm and make some safe relay switching software and then I can start to test it in the real world.
Cordially
Chris
Two recent quotes, at either extreme look like this.
>>>>>>>>
I've discussed about the parameters you sent to me. Accordingly, I'd like to recommend you our EP60Ah battery. I suggest two EP60Ah batteries in parallel connection to reach 120Ah. This model of EP 60Ah can discharge at 1C-2C at normal working condition and 5C at peak current. This way, they can totally meet your request on running current and peak current without any damage to the batteries. Also, according to your proposed voltage of 100-140V, it requires 33 batteries of 120Ah in series connection. Thus, you need totally 66pcs EP60Ah batteries.
And the FOB price for a single EP60 is USD 148.97. The total price for a pack without BMS and charger is USD 9831.73. Additionally, do you need BMS and charger from us? If you do, I will quote for you next time, ok?
>>>>>>>>>>>>
And this next one looks far too light to be true !
>>>>>>>>>>>>>>>
we have calculate the unit price for u:21945USD,the technic preference list as below:
1. Nominated Capacity:100 Ah
2. Output voltage:100V-140V
3. Output Current:800A max
4. The power Dimensions:450mm×400mm×350mm
5. Weight:65kg
6. Package:air-shipped box with wheel
>>>>>>>>>>>>>>
One company came up with a 48V 100Ah pack of LiFePo for £595 but asked for more details before they could quote more specifically, I bet it climbs up a bit but I'll let you know, I actually think they made a mistake with a decimal point !
I should get some more work done on the battery balancer on my blog later this week. I have several reports to submit for my exams tomorrow which have been holding me up. The only thing I have left to do is write the charging algorithm and make some safe relay switching software and then I can start to test it in the real world.
Cordially
Chris
-
- Posts: 244
- Joined: Tue Dec 11, 2007 11:26 pm
Another reply. This time, for 90Ah Lithium ( -ion ?)
In reply to a request for thirty 90Ah cells, (voltage 2.5V-4.5V) the reply is
>>>>>>
Dear Chirs:
Pleased to receive your letter.
Our best price is 1.3$ /AH FOB NINGBO
Enclosed please to find introduction of BMS
Looking forward to your reply!
>>>>>>>>>
About $3500, or £1750
It seems a biut low to me, but that does not include BMS, which is something the company can also provide. I will have to ask them what the maximum performance for these batteries is.
In reply to a request for thirty 90Ah cells, (voltage 2.5V-4.5V) the reply is
>>>>>>
Dear Chirs:
Pleased to receive your letter.
Our best price is 1.3$ /AH FOB NINGBO
Enclosed please to find introduction of BMS
Looking forward to your reply!
>>>>>>>>>
About $3500, or £1750
It seems a biut low to me, but that does not include BMS, which is something the company can also provide. I will have to ask them what the maximum performance for these batteries is.
-
- Posts: 113
- Joined: Fri Oct 12, 2007 6:39 pm
- Location: Essex, UK.
- Contact:
Hi Guys,
You may see this post elsewhere, but can I invite you all to post your vehicle specification by answering the Q & A in this thread.
http://batteryvehiclesociety.org.uk/forums/viewtopic.php?t=643
I can post up the required battery specification in LiFeBATT (LiFePO4 batteries including BMS and charger) and then PM you the current price, you can then choose whether you want to post up the price or not.
Cheers,
Ian
You may see this post elsewhere, but can I invite you all to post your vehicle specification by answering the Q & A in this thread.
http://batteryvehiclesociety.org.uk/forums/viewtopic.php?t=643
I can post up the required battery specification in LiFeBATT (LiFePO4 batteries including BMS and charger) and then PM you the current price, you can then choose whether you want to post up the price or not.
Cheers,
Ian
Electric chopper ebike with PUMA motor (1.2kW) and 36V 20Ah LiFePO4 batteries. 23 mph & 20 mile range with no peddling (Sorry, what are peddles for?).
_______________________________________
LiFeBATT UK Distributor
www.lifebatt.co.uk
_______________________________________
LiFeBATT UK Distributor
www.lifebatt.co.uk
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