Lithium cell tests

[woody]

Lithium cell tests

Some info here:-
http://www.fmadirect.com/support_docs/item_1229.pdfhttp://www.fmadirect.com/support_docs/item_1229.pdf

[dragonmaster_1]

Lithium cell tests

Hi John
Been trying to get in touch dont know if you got my emails. If not could you email me reference what we talked about at the EU champs
Regards Tony.

[terrorhurtz]

Lithium cell tests

Sent an email Tony.

Yes, the ones in the DeWalts are the ANR26650 cells (26mm diameter, 65mm long). These are the only cells that A123 currently produce. The larger cells (M1 HD and M1 Ultra) are not in production yet.

The A123 cells do seem to perform slightly better when warm, but apparently they still suffer a reduction in life if they go over 60 deg C.

The main reason to balance the cells is so that we can use simple chargers at competitions - so we dont have to fiddle around connecting all the balance wires every time they need to be charged. Also cheaper.

[woody]

Lithium cell tests

Commercial chargers are now availiable but the associated multicell balancing is not
http://www.astroflight.com/store/store-type-tem.html?item=products:af-106-123&sid=0001jLBTKVBTuxwtQ82c916http://www.astroflight.com/store/sto...:af-106-123&si d=0001jLBTKVBTuxwtQ82c916

[woody]

Lithium cell tests

This German manufacturer can supply A123 gear ... at a price ...the charger is expensive but it has a great range.
http://www.first-products.de/pulsarbeschbgengl.htmhttp://www.first-products.de/pulsarbeschbgengl.htm

Cheap six cell balancer .... can these be Daisy chained?

http://www.astroflight.com/store/store-type-tem.html?item=products:af-106-123&sid=0001jLBTKVBTuxwtQ82c916http://www.astroflight.com/store/sto...VBTuxwtQ82c916

(Message edited by woody on August 09, 2007)

[leorcc]

Lithium cell tests

Schulze in Germany has also confirmed that next to its line of chameleon chargers their LipoProfiBal8 and 14 is also suited for balancing A123 systems cells.

[terrorhurtz]

Lithium cell tests

Woody - I think what Andy meant is that there is no 10 cell balancer currently available. It is anticipated that most heavyweight robots will use 10 cell packs. The Astroflight only does up to 6 cells.

[leorcc]

Lithium cell tests

Schulzes biggest one up to 14 (see other topic).

[bugs]

Lithium cell tests

Can we keep the techincal discussion on Li-technology for another topic?
The problem I have at the moment is that I work with lithium batteries on a professional level, and therefore have a good understanding of the possibilities and risk involved. Yet even though the A123 cells seem safe enough (not more dangerous than NiMh) and I am perfectly capable of handeling the cell balancing problems, Im not allowed to use this technology.
This is frustrating, especially since I have to wait until other teams have demonstrated its safety, and effectively have quite a sizable advantage over the rest. This is assuming they are not obliged to couteract the weight advantage.
Why not provisionally allow the use of A123 cells, with an obligatory through techcheck to make sure it is used correctly?

[andy_kane]

Lithium cell tests

Stefan,
While you may be quite capable of handling A123 cells safely there will be be quite a few teams that cannot as yet.

Could you mail useing info@fightingrobots.co.uk with what info you have please. It would then be put around the test group.

On A123 subjects can we transfer to the thread on safety discussions please?

[big_nipper]

Lithium cell tests

Above 5 posts moved here from General Chatter.

[grant_ploughbot]

Lithium cell tests

Stefan - I have been ringing round all sorts of companies (ripmax, Thunder power, kokam etc) and not one of them can give me a straight answer to my question. Do you know how dangerous the fumes of a lithium (and other batteries, i know NiCads are very bad) in a fully closed arena are? Our featherweight arena is fully enclosed, and the smell of a burnt out motor lingers in the air for a while and we are concerned about the effects of a burning battery. Venting the arena wouldnt be a problem to do, but I would breathing apperatus be needed or is it very low risk?

If anyone knows the answers could you please let us know asap - Safety is our largest concern and with a fully enclosed arena things like too much C02 or other chemicals in the air could be hazardous.

[bugs]

Lithium cell tests

On my desk I have some info on a Lithium-Cobalt-Nickel-Oxide cell, which is the kind that burns violently. Unfortunetly I cant tell you which cells these are, but they are NOT A123 cells.

It states:

Suitable extinguishing media: Dry powder. Metal fire-ex extinguisher typ PM12i, Metal fire-ex powder typ PL-9/78 DIN/EN 3SP-44/95 Carbon dioxide
Extinguising media that must not be used: Extinguisher type D, Water spray jet.
Special exposure hazzards: Risk of formation of toxic pyrolysis products. In the event of fire the following can be released: Hidrogen fluoride (HF).
Special protective equipment for firefighters: Use self-contained breathing aparatus. Wear full protective suit.
Additional informatio: Cool containers at risk with water spray jet. Fire residues and contaminated firefighting water must be disposed in accordance with local regulations.

Even though the warning, I know the company use water for extinguishing them.
I also have a list of chemicals used in the cell. Mail me if you want it, Im not going to disclose this on an open forum I will have to ask if such information is also available for A123.

[leorcc]

Lithium cell tests

Here are some MSDS (Material Safety Data Sheets) for various battery brands and materials:

http://www.batteriesplus.com/t-msds.aspxhttp://www.batteriesplus.com/t-msds.aspx

[grant_ploughbot]

Lithium cell tests

I dont know the situation on this, but will the robots testing the A123 cells be using them at this event?
I hope not as it is a big disadvantage to the other teams in the competition as large weight loss can be gained with these batteries and higher performance (24v bosches ran on 30V). It might be a little late to mention it as I expect the teams using these batteries have probably bumped up the weight to 102kg now but i know If i was in the competition I would certainly not be happy with it!
Hopefully I havnt noticed it anywhere that they are already banned from the UK Champs