Doc_Wui

Grin Techbology's take on ebike fires and UL testing, March 13, 2024,


The first part is the history , but you can skip to around the 30 minute mark. The takeaway is they could not get a modern battery with brand name cells to catch on fire, He believes it's low quality cells, not user abuse, to be the root cause of spontaneous fires. .UL testing won't catch low quality,

2old

IMO, his testing was very shoddy, had no controls, was too limited to say anything definitive and was basically self-serving for his company. His statement that the major cell manufacturers seem to have a handle on controlling problems didn't surprise anybody

mpetry912 

regardless of the methodology I agree with the conclusions of the report

Grin has the advantage of seeing many ebikes and batteries so their basis for sampling is solid

/markp

2old

Grin tested their product, so their conclusion is they couldn't make their product fail. If they had tested other products and they didn't fail either, they would have to report they couldn't make any battery fail. I used to think they were on the leading edge, but this poorly designed study and the reports I've read about their poor CS makes them a company to avoid IMO. However, their fan boys will probably still crow about them.

Doc_Wui

The only things I've bought from Grin is a pair of 20" x 60mm" Weinman rims. Pretty hard to find, I think their GMAC geared motors are a flawed concept, Satiator too expensive, and their torque sensor implementations way too expensive and cumbersome. I do think they know how to build batteries.

I am dubious about the test where they discharged batteries to zero, revived them, and nothing happened. If they had let them sit 30 days at zero, I think results would have been more sinister. If I know this so do they,. Maybe quality cells can take a short excursion to zero. Meanwhile, youtube is full of videos where people are reviving dead cells for their vaping pens, I found a stat where ER stats had 2035 injuries 2015-2017 from vaping,

When I was in the manufacturing business, another path to UL approval is to be certified for self testing. Requires complete control of the manufacturing process, with full documentation. A UL inspector gets to take a annual junket out to your shop to review the process.

Smaug1

False.
A prerequisite for UL certified battery pack is to use certified cells. (IEC 62133) Part of the cell certification is testing for abnormal conditions; making sure the cells vent properly rather than explode.
Part of the battery pack certification is to require adequate ventilation or to test the pressure handling ability of the pack.

The reason the modern cell from a brand name would not catch fire is because they're certified and they have to pass the tests to get certified.

More info can be found in this thread: https://www.bikeforums.net/electric-...fications.html

Dewey101

I asked Justin in January if there are any UL compliant batteries he would recommend for DIY ebikes and he replied "we will have UL2271 certification of our LiGo 10X batteries once those are ready for release." So regardless of whether Justin thinks UL certification is a marketing gimmick he is prepared to have their new batteries UL certified. That does not strike me as "poor CS" but instead Grin responding to customer requests for UL compliant DIY 3rd party batteries.

2old

My comment on their CS was related to stories I've read about problems with Grin's products. Big deal getting UL certification; it'll be the norm soon. As I stated, the fan boys will jump on this. You seem to be an excellent individual to "IGNORE"!

Dewey101

There need to be more (any) 3rd party UL compliant batteries for the DIY market. Grin Tech say they are going to do it. I asked EM3EV last year if they would follow suit but I don't know where they are on getting their new generation of battery packs UL certified. I understand from an exchange with Ravi Kempaiah also last summer this is an aspiration for Zen Electric. All this is simply to observe suppliers say they will respond to market demand.

speedy25

Sooooo, this whole "problem" started with NYC having a bunch of fatalities of people living upstairs over a bike shop. They think they can fix the problem with UL certification.

It wont fix it. There are too many OTHER problems to deal with they are totally ignoring.

Justins video was SPOT ON for information about batteries, along with some great history for how we got here. Its the first time I have encountered ANYONE tackling the subject and getting it all right.
Its the only info I would feel good about to send someone to for correct information.

No, I'm not a company shill. I have the satiator (NO! Its not too expensive!! Having the right charger for different chemistries would cost much more!) and the battery tester. The tester is great to confirming a battery is any where near its claimed specs, AND it measures internal resistance. I think that is the real problem in NYC. Its constantly mentioned people cant afford replacement batteries so they keep charging their old ones for days at a time instead of hours. By then they have become nothing more than a heater waiting to catch fire. And of course the cheap cells are also to blame.

In contrast, I am surrounded on a daily basis with batteries from all brands, differing voltages, and capacities. I have no worries about them. While others have drank the kool aid and wont let an off brand bike in their store. No problem. I'll make the money off that service.

Nice to see a thread on the Grin Video.

-SP

2old

For some, a Satiator is a bargain. For me, the $50, 52V charger from Luna Cycle is a much better option since it still functions perfectly after eight years and the only DIY batteries that I have are 52V (with the exception of a 36V which came with a Haibike). To each his own.