[david85]

Its getting close to putting my money where my mouth is with all this talk of lithium batteries. Testing isn't quite done yet, but I wanted to get the word out early to give plenty of time if anyone else wants in.

I can't give an exact date yet, but its looking like we will place the order for the saturn conversion before the end of the year.

I'll be ordering 45 3.2V 200 AH lithium iron phosphate cells to make up a 144V battery pack for 28.8 KwH's of reserve (and hopefully more than 100 miles of range at freeway speeds).

Please be aware that there is risk involved here, and I was told that the warranty is only 12-18 months even if the battery could in theory last more than 10 years.

[chamilun]

well, Ill ask the big question first: what kind of money are you talking about? 15K?

[david85]

Originally Posted by chamilun

well, Ill ask the big question first: what kind of money are you talking about? 15K?

The price for my battery will be close to $16000 including BMS and charger. They don't seem to have a problem with an order that small, so your order could be any number you want on top of that. It doesn't have to be 45 cells like mine.

Originally Posted by RKM

David,

I'm very interested! I think I would be wanting 45 cells 3.2V with 160Ah (if available) for a pack with 23 KWh.

Could you remind us of the discharge C ratings (continuous and max burst) as well as weight per Wh?

Do they provide a suitable charger and BMS for an EV application? Quality and cost?

I'll be very interested to know a cost estimate per Wh. The timing works well for me as I won't need batteries before spring.

Your higher amperage testing of these batteries will let us know how suitable they will be (though the risk remains for long term reliability!). Thanks again for taking the lead on these batteries.

Rob

I can ask if they offer a 160AH cell (they should), my tests are for 200AH cells though. But The quality SHOULD be the same across the product range.

Constant C is 1C, and max C is 5C (for 15 seconds or less). For your battery, you would have 23.04 kw of power for cruising and 115.1 kw for acceleration (assuming 100% efficiency).

WH/Kg calculates to 88.9 for my 200AH cells (before calculating for charger and BMS). Most of the LiFePo4 like this seem to be between 85 and 100wh/Kg. The older LiPo 3.7V soft cells can be up to 160 wh/kg from what I was able to find. Its been said that the older LiPo technology was good for up to 300 wh/kg in some more general info sources, but I never found a supplier that had anything like that in their product listings. Electrovaya (canadian) claims to have 400wh/kg, but they never returned my Emails.

They do provide a charger matched to the battery if requested. I can only comment on the charger they sent with my 12.8V sample battery which did seem to be of good quality, I had no problems with it. The price for the charger for the 144V battery came to $1503.60. The price for the 12.8V was $128.80.

The cost per WH for just the battery is ~$0.466/wh. BMS and charger are added on top of that. The price quote for my battery works out to $0.55/wh with everything included. Based on this you could now get an idea for what your battery would cost. I do not yet have a price for the freight though.

Yes, there is a risk for the long term, all I can say is that the older LiPo chemistry was good for up to 10 years and LiFePo4 is more stable so maybe it would last longer. But theres no way to be sure so take that into account if you decide to buy.

Higher C tests are comming next......

All prices are in US$

If we could get the price of oil to come back up, that would give the canadian dollar some more strength. Maybe we should all yell "supply shortage!!!!" really really loud at the same time. Thats usually all it took in the past to inflate the price, LOL

[RKM]

Originally Posted by david85

Its getting close to putting my money where my mouth is with all this talk of lithium batteries. Testing isn't quite done yet, but I wanted to get the word out early to give plenty of time if anyone else wants in.

I can't give an exact date yet, but its looking like we will place the order for the saturn conversion before the end of the year.

I'll be ordering 45 3.2V 200 AH lithium iron phosphate cells to make up a 144V battery pack for 28.8 KwH's of reserve (and hopefully more than 100 miles of range at freeway speeds).

Please be aware that there is risk involved here, and I was told that the warranty is only 12-18 months even if the battery could in theory last more than 10 years.

David,

I'm very interested! I think I would be wanting 45 cells 3.2V with 160Ah (if available) for a pack with 23 KWh.

Could you remind us of the discharge C ratings (continuous and max burst) as well as weight per Wh?

Do they provide a suitable charger and BMS for an EV application? Quality and cost?

I'll be very interested to know a cost estimate per Wh. The timing works well for me as I won't need batteries before spring.

Your higher amperage testing of these batteries will let us know how suitable they will be (though the risk remains for long term reliability!). Thanks again for taking the lead on these batteries.

Rob

[Technologic]

Originally Posted by david85

Its getting close to putting my money where my mouth is with all this talk of lithium batteries. Testing isn't quite done yet, but I wanted to get the word out early to give plenty of time if anyone else wants in.

I can't give an exact date yet, but its looking like we will place the order for the saturn conversion before the end of the year.

I'll be ordering 45 3.2V 200 AH lithium iron phosphate cells to make up a 144V battery pack for 28.8 KwH's of reserve (and hopefully more than 100 miles of range at freeway speeds).

Please be aware that there is risk involved here, and I was told that the warranty is only 12-18 months even if the battery could in theory last more than 10 years.

Need more information.

cylinder cells? good BMS included etc.

[david85]

Originally Posted by Technologic

Need more information.

cylinder cells? good BMS included etc.

The cells are prismatic, BMS and charger are matched to the battery if requested (recommended).

More info here:
http://www.diyelectriccar.com/forums...ead-21887.html

[Technologic]

Originally Posted by david85

The cells are prismatic, BMS and charger are matched to the battery if requested (recommended).

More info here:
http://www.diyelectriccar.com/forums...ead-21887.html

thanks for the info I actually forgot you were testing out this battery in that thread

I'd really be interested in a 8kwh pack for my custom shell car coming up if the BMS is well designed (therein lies the problem for MOST lithium sets lifetime figures).

500 lb custom fiberglass car needs lithium IMO... let me know more about the BMS when you find out...

and your most recent 60 amp load test... i'd like to see if you can charge/discharge it at that amperage and see if DoD is at all measurable after say... 10 times (maybe 0.01v? I don't know)

[david85]

Originally Posted by Technologic

and your most recent 60 amp load test... i'd like to see if you can charge/discharge it at that amperage and see if DoD is at all measurable after say... 10 times (maybe 0.01v? I don't know)

Hmm, thats not going to be easy. I'm heading into winter here and even minor drop in temperature could skew the results, and our shop is not heated. I'm afraid I really don't have any conclusive way to verify the claimed cycle life. I have heard that TS cells have been verified through independant testing for the advertised cycle life. My impression so far is that these batteries are at least as good as thundersky.

For one thing, they don't have to be banded to prevent swelling from normal use. These cells also have built in internal redundancy because they are composed of many internal cells connected in parallel. My understanding is that TS uses a single large cell for each module. So if one cell fails, the car stalls.

[Technologic]

Originally Posted by david85

H\

For one thing, they don't have to be banded to prevent swelling from normal use. These cells also have built in internal redundancy because they are composed of many internal cells connected in parallel. My understanding is that TS uses a single large cell for each module. So if one cell fails, the car stalls.

Well assuming you're not using a series/parallel configuration.

[hardym]

Within in the last two weeks I got quotes from both Thundersky and Hipower for $300 per 200 AH cell at quantity of 48, plus shipping.

This price is too high. I have heard that bulk purchasers are getting cells at $.30/ Wh (or about $1/Ah) which would be about $200 per cell. This is only twice the price of lead, so that is encouraging. So look for this kind of pricing and I may consider buying in. For a street size conversion vehicle, this would be 48 cells at about $10K, but giving a range of more than 75 miles.

There are two significant concerns with upgrading from Lead to Li for a full size street vehicle (48 + cells)

1.) There are no available BMS. Without BMS high voltage cell protection on the charging cycle, you run the risk of cooking your cells. There are several people working on solutions (like me), and lots of one-off prototypes but no shrink wrapped solutions.

2.) There are no Lithium prismatic success stories (e.g. thundersky-type block cells). I have heard of serveral people saying that they are in the process of upgrading to Li, then just drop off the earth. What happened to all these attempts? As far as I know there are ZERO operating Li-prismatic street legal vehicles operating in southern California. I don't mind being an early adoptor, but I dont want to repeat mistakes.

Frustrated in CA
Mark.

http://evalbum.austinev.org/1352