Just happened to stumble across this article ( Why This Ultra Dense Battery Breakthrough Matters - Undecided with Matt Ferrell.) and was curious if anyone else had seen or done any research into high density batteries and had any input on the subject. I'm contemplating doing a battery build soon and just want to do a comfortable amount of research on batteries until I have enough saved up to start buying what I need. At my current rat I am able to put aside around $50-$100usd a month.
An interesting Development, Any research?
- Thread starter Talzoid
- Start date
If it's helpful, there are some posts regarding the Amprius stuff:
endless-sphere.com
Search results for query: amprius
endless-sphere.com
eMark
100 kW
Would be helpful if you could tell us what Ah capacity, continuous Amp power rating is required for your application (e.g. ebike or EV). What size dcbl motor (maximum wattage requirement) do you plan to use?
FWIW, that "Amprius stuff" will be way too expensive (e.g. military) for consumer ebike use IF ever available for consumer ebike use. You may want to consider a custom build with used EV pouch (e.g. VOLT) cells IF power, apeed and excellent range is your primary goal ... checkout: batteryhookup.com
12kW eBike hub motor?
Hello. Is QS 273 V3 40H the most powerful hub motor on the market or there is something more potent? I would love to put my hands on hub motor that has 12kW of nominal power to use full potential of Sabvoton 72200 and QS 273 has only 4kW of rated power :/
www.endless-sphere.com
Salvaged EV cells index: Leaf, Volt, Tesla, Zero, etc
This is not a discussion thread, just add links that have details and/or pics. As more of these EVs are involved in wrecks, their battery packs are coming up for sale at surprisingly affordable prices. Cell dimensions (all in millimeters): Tesla-3, cylindrical 21700 (21mm X 70mm) Tesla-S...
www.endless-sphere.com
What kind of pouch cells are these?
My 1 year old battery started dying. Looks like a few cells had a leak and I need to replace them but I can't identify or find a replacement. Do any of you recognize these? Also why would they have leaked from the corners? Is it mechanical or over-charging or something else. Size is 9x6.5 inches.
www.endless-sphere.com
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Out of curiosity I actually saw some Amprius surplus cells being sold on ebay the other day, at least the listing said they were manufactured by them. They were quite pricey and didn't have all the specs if I recall. They were obviously made specifically for some product. Can't find the listing now but I don't expect it's really worth getting excited over new battery tech until it's at the production scale at which we can actually buy it and at reasonable prices.
Interesting to hear you spotted some!
You know, it was A123 batteries and RC Lipo that really blew up this forum. It changed what you could do with a bike. I'm interested in seeing the next wave too.
Right now i think the highest density cells we've see anyone buy are 290whrs/kg EVE 58A cells:
http://queenbattery.com.cn/our-prod...-36v-5800mah-3c-battery-cell-inr2170058e.html
Nice cells BTW if you want to rock them at ~1C
Supposedly, Lishen has 5.8ah 21700 cells also, claims 297 whrs/kg
Lishen High energy density LR2170SK 5800mah 21700 lithium ion battery cell - LiFePO4 Battery
I can't find any reviews/discharge graphs of these cells online. The DIY scene must be on break..
You know, it was A123 batteries and RC Lipo that really blew up this forum. It changed what you could do with a bike. I'm interested in seeing the next wave too.
Right now i think the highest density cells we've see anyone buy are 290whrs/kg EVE 58A cells:
http://queenbattery.com.cn/our-prod...-36v-5800mah-3c-battery-cell-inr2170058e.html
Nice cells BTW if you want to rock them at ~1C
Supposedly, Lishen has 5.8ah 21700 cells also, claims 297 whrs/kg
Lishen High energy density LR2170SK 5800mah 21700 lithium ion battery cell - LiFePO4 Battery
I can't find any reviews/discharge graphs of these cells online. The DIY scene must be on break..
harrisonpatm
10 kW
- Joined
- Aug 8, 2022
- Messages
- 824
Oh thank you so much, I'm thoroughly pleased someone else has seen it besides me. I was going to be the first reply to this thread, but I wanted to be fair and not hate on him right away in case someone else likes him. He's nothing but 10-minute summaries of just the headlines of the most superficial pseudo-science puffpieces, while also humblebragging about the new house that he's building.
New supposedly non-flammable battery for ebikes:
Non-flammable battery now available to public; promises to end e-bike fires
Absolutely NO idea on what the specs for these are, and can't find any information online. I decided to fill out the request for specifications and am waiting to hear back.
Non-flammable battery now available to public; promises to end e-bike fires
Absolutely NO idea on what the specs for these are, and can't find any information online. I decided to fill out the request for specifications and am waiting to hear back.
Instead of shooting it, let's do something much more common and realistic:
Build a pack of those cells up from random lots of cells with different characteristics so they are not matched and will not charge or discharge at the same rate.
Install a common cheap crappy BMS to the cells, then discharge the pack to empty. Make sure a BMS is used that has no balancing function and that is either broken (shorted charge FETs) or just doesn't correctly restrict charging once cell voltages drop below the normal limiting ranges.
Then let it sit for a few months hooked up to a common cheap ebike controller/display setup, so the BMS and/or display will drain the pack further (to the point where typical cells would be far overdischarged).
Then recharge the pack with a cheap charger capable of as high a current as possible even when the pack is too low to do that.
Cycle it this way repeatedly, and see if anything catastrophic happens.
Test a bunch of packs this way, and while doing that, also test a bunch more that have been soaked in water and dried repeatedly, while in operation, and test a bunch more that have been dropped and crashed, etc. so that some of the cells are no longer connected to the pack, and some of them have damaged casings, etc.
Because...those are the kinds of things that almost certainly cause the fires.
Not many people are riding in hunting areas or combat zones.
Build a pack of those cells up from random lots of cells with different characteristics so they are not matched and will not charge or discharge at the same rate.
Install a common cheap crappy BMS to the cells, then discharge the pack to empty. Make sure a BMS is used that has no balancing function and that is either broken (shorted charge FETs) or just doesn't correctly restrict charging once cell voltages drop below the normal limiting ranges.
Then let it sit for a few months hooked up to a common cheap ebike controller/display setup, so the BMS and/or display will drain the pack further (to the point where typical cells would be far overdischarged).
Then recharge the pack with a cheap charger capable of as high a current as possible even when the pack is too low to do that.
Cycle it this way repeatedly, and see if anything catastrophic happens.
Test a bunch of packs this way, and while doing that, also test a bunch more that have been soaked in water and dried repeatedly, while in operation, and test a bunch more that have been dropped and crashed, etc. so that some of the cells are no longer connected to the pack, and some of them have damaged casings, etc.
Because...those are the kinds of things that almost certainly cause the fires.
Not many people are riding in hunting areas or combat zones.
orcasprout
1 W
- Joined
- Jun 25, 2022
- Messages
- 50
Sounds like you've got your ES certification protocol written. I can see why a UL cert is kinda pricey.
There's other good torture tests out there, too, but when you look at things like the hoverboard fires, you'll see the various things I listed as reported / diagnosed problems with some batteries and chargers in those types of devices, so it should be a useful test.
The main Idea I'm looking at is for a car replacement and for my specific needs I'm looking at about 5.5-7.5kwh going for 60v-75v (yes I know the standard is 72 but It's customized for my needs) that can max out at no more then 8kw (very hilly areas on some of my pathing some as much as 17% for 1,000 feet or so and this is about 5% of my daily riding though) but would be on average 3.5kw draw. The battery is the hardest part since I still am not sure where I'll be positioning the battery nor the shape until I am more confident in the cells I'll be getting.
Also as a little more info these are MAX numbers as I have done a few simulations using really poor conditions of 17% grade, 4-5% dtloss, 10mph head wind, 400lb total weight and .05 Crr, Again this would account for at most about 5% of my daily riding but I still want to account for the worst as my standard to learn what is available and possible.
An interactive model-based calculator of cycling power vs. speed
Found these on Ebay: Amprius E485795C 3.85V 4.90Ah 400 Wh/kg Silicone Anode Rechargeable battery NEW | eBay
They claim to be Amprius batteries. Now I have zero way to verify this and don't feel like contacting the seller, but these batteries seem very close in energy density to typical high capacity phone batteries. They don't seem particularly power dense either. Seller is claiming 400wh/kg.
They claim to be Amprius batteries. Now I have zero way to verify this and don't feel like contacting the seller, but these batteries seem very close in energy density to typical high capacity phone batteries. They don't seem particularly power dense either. Seller is claiming 400wh/kg.
- Model: E485795CH
- Voltage: 3.85V
- Discharge cut-off : 3.0V
- Max Charge Voltage : 4.40 V stop @ <0.098 A
- Max Continuous Discharge :0.7 C (3.43A) , Capable of 1C @ 25c ambient
- Capacity: 4900mAh
- Capable of 4.9 A discharge for a short time in room temp 25C
- Power Capability 18.86 Wh @ 1.5 C (7.5A) higher power is available at lower discharge current .
- Size max: 4.95 x 57.5 x 96.5 mm
- Weight = 62gr
- Internal impedance: @ 1Khz < 60 mho :
- Guaranty cycle life : >500 Charge/discharge cycle @0.2C (.98A) to 80% capacity
- Max temp @ 4.9 A discharge <40 C ,
