gromike
10 kW
How does one capacity test hundreds of cells?
Grin’s perspective of Ebike fires
- Thread starter Eastwood
- Start date
Hummina Shadeeba
10 MW
Seems a good resource for recycling batteries:
Recycling Center Search - Earth911.com
Find recycling centers and services in your neighborhood.
search.earth911.com
floydr
100 W
4 at a time with one of the 4 bay testers, I use Opus BT-3400 I have 4, one with external 26650 cell holders I use for A123 26650 cells. It takes time especially since you should only test the cells while you can keep a close eye on them. Not sure what @harrisonpatm uses. Use Charge only multi bay chargers To pre charge the cells prior to putting in the tester, making sure you remove the tested cells at the finish of testing cycle. I used the Charge/discharge/charge mode you can cut the time of a single a123 26650 2500mAh cell to ~2hours 45 minutes. I could test 12 cells in a bit over 8 hours. 18650's 2600mAh 16 cells at a time 48 cells in ~9 hours x many many days
You can also get the MegaCellcharger it does 16 18650's at a time.
Later floyd
...and to test and track capacity of entire packs I use one of these.
docw009
10 MW
I use the aliexpress atorch version at 1/2 the price. The glowing circle is a CPU cooling fan, The system can only dissipate 160 watts, so the max draw on a 48V pack is around 3 amps. That's a 3AH discharge rate, so it only takes 3-5 hours to rate battery capacity,
With the battery BMS holding LVC to 3V/cell instead of 2.5V/cell, you lose some of the rated capacity. Voltage sag in the battery contributes too, I usually see at best, 90% of rated cell capacity on the tester,
Real life capacity on an ebike further drops the useable capacity. I guess 80% is a good rule of thumb for a small battery. For example, a Sanyo GA pack was 90% on the tester and 83% on my bike. If you use massive 6P packs, you'll get better numbers,
.
Exactly the one I have. I run a complete discharge with it on each pack at the end of each season and record the results so I can watch how each pack does over time. I run the same cells but by Panasonic (NCR18650GA) in 11p.Is this the one to get? https://www.aliexpress.us/item/2255...JoZGQ4D4&utparam-url=scene:search|query_from:
Says 2 to 200V. Does that mean you can load test any battery between 2 to 200V?
Yes and yes. That's the one and tests from single cells up to the largest ebike battery pack. I also use it to test the 100ah
LiFePO4 batteries in our van.
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Having done no research other than finding a link with a temperature range 
I'm wondering if there is a use for this PCM type:
www.tsksupply.com
(specs quoted below).
I ask because we toss out one to several of these a week, as a 6-pouch pack. I have one here that could be used for testing, but (without more info and some pondering that may not be worth the time) I'm not sure how to implement / instrument a useful test for say, using it to protect a battery pack, or a controller, etc. Or even just to keep it at a more constant temperature.
I have an old Luna 18650 pack that (if it's still functional) would be a useful test bed, as it is not able to supply much current without heating up quite a bit. "Luna Cycles"? 13s 4p Samsung 26f "48V 10Ah" pack
My EIG packs don't experience any noticeable temperature change during a ride so not much testing I can do with them.
I'm wondering if there is a use for this PCM type:
Adaptek Essential 24 Pouch 72 Count Case
Your one stop shop for shipping and packing supplies for exotic plants,pets, fish, reptiles,flowers, sea food, chocolate and more.
www.tsksupply.com
I ask because we toss out one to several of these a week, as a 6-pouch pack. I have one here that could be used for testing, but (without more info and some pondering that may not be worth the time) I'm not sure how to implement / instrument a useful test for say, using it to protect a battery pack, or a controller, etc. Or even just to keep it at a more constant temperature.
I have an old Luna 18650 pack that (if it's still functional) would be a useful test bed, as it is not able to supply much current without heating up quite a bit. "Luna Cycles"? 13s 4p Samsung 26f "48V 10Ah" pack
My EIG packs don't experience any noticeable temperature change during a ride so not much testing I can do with them.
offGridDownUnder
10 kW
paraffin blend
You mean that stuff that ignites and burns when it becomes hot?
You mean that stuff that ignites and burns when it becomes hot?
:lol: Yeah, but it's ignition temperature is far above anything the battery will experience (even in our desert weather).
If the battery itself ever fails and ignites, having burning wax included in the conflagration would be the least of my worries.
I would lose the trike either way, there's no way I could put out a 2-3kwh battery fire of any kind inside, along with the wooden-sided trike (if it wasn't wood, it'd be plastic, so...).
So, just pondering whether or not the PCM would make any performance difference to a battery pack design.
AFAIK, most (maybe all) of the PCMs used in existing battery packs that have been discussed over the years on ES are wax / paraffin based. Tried to find the threads and posts about them to check, but can't actually find any ATM.
Cephalotus
10 kW
- Joined
- Jun 18, 2012
- Messages
- 762
Best way to extinguish an ebike-battery fire besides dumping it into water is to use a fire extinguisher with F-500
This stuff is really good:
or
Here it extinguises a zirconium fire which is almost impossible to extinguish:
I bought myself a 9 Liter model:
Of course you need to be at home to use it...
This stuff is really good:
or
Here it extinguises a zirconium fire which is almost impossible to extinguish:
I bought myself a 9 Liter model:
Of course you need to be at home to use it...
If you install heat and/or smoke sensors at the battery location, you can create a mechanism to engage the fire extinguisher. You'd need to ensure it is setup so that it's output covers the fire properly; it might take more than one to do it from different directions like you could if you were there.
F-500 Encapsulator Agent | Commercial Fire Extinguisher
Want to get started with our class A or class B commercial fire extinguisher? Our F-500 Encapsulator Agent is the best solution for any hydrocarbon fuel spill.
hct-world.com
Cephalotus
10 kW
- Joined
- Jun 18, 2012
- Messages
- 762
Another effect is that this water-F-500 mixture evaporates at 70 °C rather than 100 °C. This makes the cooling effect much better.
The good thing about it is that, compared to Class D fire extinguishers (which don't work very well with burning lithium batteries anyway), it is perfect for use on any “normal” household fire. The exception is grease fires (in the kitchen), where you have to be very careful.
The good thing about it is that, compared to Class D fire extinguishers (which don't work very well with burning lithium batteries anyway), it is perfect for use on any “normal” household fire. The exception is grease fires (in the kitchen), where you have to be very careful.
Stupidest thing to do is generate publicity as that just generates unwarranted fear. In the real world all that matters is that the odds are really low, like air travel, where the odds of crashing & being killed are less than 1% or something. So AFAIC as long as the odds of these fires happening are less than 1% there’s really nothing to talk about here & we can get back to discussing real estate prices or tips on the horses at Randwick tomorrow. IOW rational people don’t have anything to worry about here - now if you’re an ignorant fuker who’s paranoid & thinks vaping’s worse than smoking, then you’ll probably worry.
Hummina Shadeeba
10 MW
1%!? That’s a huge percentage. (Dying in a plane is definitely way less than that at about 0.00001%).
AFAIC, anything less than 1% is ok. Fact is life isn’t meant to be safe - if life was safe humans would never had existed in the 1st place.
BatteryMooch
10 kW
I hear ya’…
But it’s the concerns and discussions and education of rational people in the first place that has brought the odds of so many (bad things) happening down so low. Without ongoing talking to each other, without evangelizing for best practices, without appropriate warnings, the odds would soon go wayyyyyyy up.
Each of us gets to set own safety thresholds and degrees of concern based on the knowledge that’s being shared, of course, and that‘s the way it should be. Some will be alarmed at certain things, others couldn’t care less. But we wouldn’t even know the odds were so low for some things unless discussed it all (with the resulting and expected huge range of concern).
Fair enough & you are right of course. As an old bugger this seeming modern obsession with safety just becomes so tiring. of course we have the worst of it here in Australia. When they made wearing bicycle helmets compulsory in the 80’s , bicycle riding rates dropped 40% over night. It’s all bull, as politicians spending the money on dedicated bicycle lanes is way safer than forcing helmet use, plus studies done in Europe show that cyclists riding upright bicycles with normal handlebars fitted with a mirror, pan out at significantly better safety rates, than helmeted riders on dropbar bikes. Simply because it’s better to look at the traffic than at the front tyre rolling over cracks in the road. Look at the stats, it’s virtually always dropbar riders wearing helmets getting bowled over by cars & killed on the road. But the polies persist with their helmet obsession, it’s gotten so bad one can always pick Australian tourists in the Netherlands, Low Saxony & Denmark as they’re the only ones wearing helmets there.
Consider that 1% is one in one hundred. I am not a math person, or statistician, so I am sure this is wrong, but: If there are 100 battery powered EVs (scooters, bikes, whatever) in an apartment building, there could then be a 100% chance of a fire happening to one of them at some point in it's lifespan.
Personally, I'd rather the odds of a fire type failure be far far lower than 1%...at least a couple of powers of ten lower.
BatteryMooch
10 kW
Agreed.
And once politics gets involved it’s often more about how they want to be seen rather than what might be the right thing to do….IMO as an old bugger too.
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Epithemeus
100 W
As a slightly mathy person, a 1% chance of a battery having a fire within its lifetime with 100 batteries would end up being about a 63% chance of fire. (The perfectionist in me has to acknowledge it's more complicated because not all batteries would be at the same point in their lifecycle, but that's not going to make a significant difference)
This is absurdly high and absolutely intolerable. I am absolutely in favour of regulation, even expensive regulation, as long as it's done correctly. It sounds like UL cert is not being done correctly though, certainly not proportional to the cost. Based on what I've read the main benefit is just that cost of certification is a barrier to entry for the cheapest of garbage high risk cells. Hard pill to swallow for people like Justin that actually give a s*** about doing things properly though.
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