Lithium cell tests

[leorcc]

I agree. I know of at least 2 heavyweight teams that are on the virge of buying new batteries and would like to go to A123 but this hold-up now means they might be forced to go with different ones. We already went for new SLAs instead.

For the record, no one of the organisation of DRG has any objections to the use of A123 in all weightclasses. Nicad fires are not an issue with these cells, and neither is thermal runaway. This has been told to me by a person who designs and builds chargers and balancers for all types of batteries including Lithium nanophosphate.

[leorcc]

btw Gary: 2 cells A123 parralel is still lighter than 3 cells nicad in series (to get roughly the same voltage), and then the discharge figures are more in favour of A123.

[typhoon_driver]

true but the bank balance figures are then in favour of the nicads. This is when including the price of a lipodapter and cells.

I think I am going to stick to nicads for the time being and see how the A123 cells perform when run in multiple machines.

I am however all for the acceleration of this issue which has been ongoing for a good 9 months or so if you look back to the start of this thread.

[geeza]

The difference in Thz speaks for itself, but that is mainly due to the increased voltage. I think that when the rule is passed we will be looking to go with the A123s at the higher voltage aswell.

[m2xt]

Gary, Having tested out A123s and obviously knowing how Bot-packs perform, all I can say is about the same at best.

I feel the FRA is right in researching these cells in order to provide appropriate guidelines and not taking the manufacturers claims as face value which was as it turns our rather wise in my opinion. 70A continuous discharge, no chance in the real world, the main issue is temperature rise. I look forward to seeing the FRA recommendations as soon as they are available.

[leorcc]

Wether or not the performance is or is not the same is not a safety issue. There is no safety reason for these cells not to be allowed in all weight classes. Wether or not a roboteer will use them should be up to the roboteers.

[leorcc]

When Nicads came into the picture no roboteers were forced to go to nicads, if they wanted to stay on SLA that was fine.

When NiMh became more interesting for feathers, no one forced roboteers to go to them, if you wanted to stay on Nicads or SLA thats fine.

No one is forcing anyone to go to A123 cells, if you want to stay on NiMh, Nicad, or SLA, that is fine. But do give the roboteers that do want to use them the chance to do so.

Decisions on the investment of batteries, packs, chargers, balancers should be up to the roboteers, in the end they are the one that will have to care for their investment. Those that want to invest in this should be allowed to do so.

[maddox]

Even now a lot of roboteers stay on cheap SLAs like the Yuashas or over here, the PBQs. Even if the NiMH technology is matured a lot with a subsequent lowering of pricetag.

The A123s, in safety issues are even safer than the NiCDs of days past. I remember a certain machine shorting out the very expensive (for the day) NiCd botpacks. Without more issues than a lot of money gone up in smoke.

If roboteers want to smoke up a lot of money in abused batteries, without aggrivating arena safety issues, who cares.

[m2xt]

Leo, Perhaps the FRA insurers will take your statement There is no safety reason for these cells not to be allowed in all weight classes. Wether or not a roboteer will use them should be up to the roboteers as gospel and not require any further evidence of due diligance but I doubt it. Not often I come out in support for the FRA but for once, I am encouraged to see proper research being undertaken on what is a new technology. There is little point in harking on about what we all did years ago and got away with, it is what is expected today from a professional body that counts.

[leorcc]

Paul, all research on these issues have been done, and results of these tests have been shown here in this thread and all over the net. This is not a cell that just hit the streets 3 months ago, LiFePo4 has been in use for various automotive applications since 2005!