Danny over at Ampedbikes posted this about some bad batteries. Scary stuff.
http://ampedbikes.com...
-Vic

Really old news

I asked the importer about watt happened. The China supplier had packed the battery in the bottom of a carton containing lottsa heavy bits. With the bumps and jiggles of transport and the weight bearing down on the battery, the metal battery case was squished until the plastic liner that separated the cells from the case was worn/poked through and the live electrical bits of the cells were shorted by the metal case.

There is a FAA report from November 2009 that mentions this incident here:
http://www.fire.tc.fa...

This 2007 FAA report is extra fun if you watch the two embedded videos:
http://www.fire.tc.fa...

...and there are lottsa vids on Youtube of lithium-based fires:
http://www.youtube.co...

Butt these are early daze for lithium chemistries. We are still learning how to handle it safely. Banning the stuff completely now would be like banning the first bicycles `cause somebuddy fell off and bumped their head?

Anyway, this is the reason why I bought LiFePO4. For now it's a pretty safe chemistry compared to other lithium cells, and the trade-off is lower power and energy density.

Here is a vid of Luke cutting the head off a live LiFePO4 cell (a Headway, same as mine):



I am far more concerned about being run over in traffic than I am about any fire caused by my battery! The danger these daze isn't with the lithium cells themselves, only watt happens when the high energy in the cells is accidently released all at once (a short)

Lock

Vent Time
What really really pisses me off is the utterly huge selection of battery chemistries out there that while the chemistries are fairly sound the manufacturers cut corners to save a buck and Quality Control takes a hike.

To summarize... There are pretty good cells out there. Where things go wrong mostly are in bad assembly and design of the wiring and electronics to monitor same. Lottsa hand assembly still going on using unskilled labour in back rooms around China... So I had my BMS hand built by Andy in Texas. I have a team of engineers and shop machinists in Concord Ontario to actually assemble the pack including good sized conductors and connectors etc.

The way I figure it, if the pack is to last a few years, a few hundred bux extra spent up front to ensure quality translates to less than a dollar a day for peace of mind and reliability and long life, so money well spent. And I'm still saving much more than this in not using public transit or a car.

loCk

I've been involved with Lithium batteries at the design/distribution/marketing level since 2001 and once Lifepo4 appeared in 2005 I was soooo happy we finally had a stable Lithium chemistry, but everyone gagged on the price. The rush into Lifepo4 drove the prices down fast to where they were (almost) affordable by the heaving unwashed masses. Any Battery that does not Combust or Explode is a good battery.

Danny over at Ampedbikes posted this about some bad batteries. Scary stuff.
http://ampedbikes.com...
-Vic

BTW Vic, there's bad blood between AmpedBikes and e-BikeKit... They have a "history" of dissing each others product online

loCk

there was a case just b4 Xmas in the States where someone was dinged with a $50K Fine for shipping his Lithium battery pack back to a Dealer for a Repair and he didn't use the Post Office Hazmat documentation and special packaging.

Dealers kinda forget to mention that if your Lithium Battery is being shipped back for a repair it is the Customer who ends up in jail and or gets the $50K Fine.

BIG CASE in Mississauga last year.

Some postal worker noticed a parcel leaking a yellow liquid and so he opens the box and sees all thes tubes with wires and fuses and well he is thinking Terrorist Bomb and the Largest Postal Station in Canada (Gateway) has their employees evacuated while the Police evacuate the businesses and homes in the area. Police, SWAT (ETF) and even the Militiary show up to remove the box to a field to blow it up.

The Yellow liquid was Electrolight which can leak.

Total Bill for the excerise handed to an e-biker was for over $1.0 Million Dollars.

Oh Yeah also an E-Biker in Ottawa placed his Lithium pack under a table to charge it and it Smoked. Library workers see the exposed tubes and think 9-11 and in come the Bomb Squad. The E-Biker was billed $40K for the incident.

I cannot remember at what altitude it is (30,000 feet I think) when Lithium batteries begin a thermal runaway on their own. The FAA in the States reported several incidences where Lithium batteries caught on fire at I think 30,000 feet and the Government takes a real dim view of their cargo planes coming down on-fire.

PS the E-Bikekit Lithium Battery packs that ignited came from a company called Golden Motors and E-Bikekit.com has stopped using Golden Motor supplied Lifepo4 packs.

AFAIK Golden Motors got their Lifepo4 from ECity (the Art of BMS).

THere is an ECity Lifepo4 (36V X 10Ah) Pack on Craigs List today for $250.00 but don't get too excited because that pack would barely power a Shwinn iZIP can motor.

PING Lifepo4 can barely achieve 25A which make it unsuitable for a lot of high power demand motors.

Headway Lifepo4 are rated at 40A Continuous which is way better and LiFeBATT are rated at 100A (which is overkill).

Headway Lifepo4 are rated at 40A Continuous which is way better and LiFeBATT are rated at 100A (which is overkill).

Straight from Headway:
http://www.xhnykj.com...

For their 10Ah cells "Maximum Discharge Current (continuable)" 150A, so 15C!

8Ah cells 25C!

For my 48V 10Ah system at a nominal 500W that's only about 10A or 1C so these cells won't EVen be breathing hard.


loCk

ok so what one should i use just so i am clear i am very new / green/ to this

For their 10Ah cells "Maximum Discharge Current (continuable)" 150A, so 15C!

is "continuable" even a word in English?

What you need to know is the "Rated Continuous Output" not the Maximum and the 38120 Cells are 40A but the BMS HW uses lowers it to 25A to 30A.

wish i can just go to a tech shop and pay and get a good job do to my ride sad as i

For their 10Ah cells "Maximum Discharge Current (continuable)" 150A, so 15C!
is "continuable" even a word in English?
What you need to know is the "Rated Continuous Output" not the Maximum and the 38120 Cells are 40A but the BMS HW uses lowers it to 25A to 30A.

`Course it's a word in English Joshua... but this is Chinglish. Like this:


...they mean "continuous"...

lLok