Bumblebee Battery Wholesale (EV battery modules and more!)

New phone. Who dis?

2 Likes

@Flasher is correct, international is international as far as customs is concerned. It might be possible in the future, but for the time being we are focusing on the contiguous United States.

1 Like

I feel like a real professional :sunglasses:

This is a battery module from a Honda Fit EV, which is made by Toshiba with their 20Ah SCiB cells. They are LTO chemistry, so 2.7V fully charged, but they are a seriously impressive cell. I’m excited to get these listed.

14 Likes

LTO are so dope! You can run that cell all the way down to 0v and charge it back up!!! Not sure exactly how much energy ithas at super low voltage levels, but its a super cool chemistry for sure

9 Likes

The $$ for just the voltage isolation in that board is higher than entire esk8 BMS’ parts costs. :joy:

7 Likes

Toshiba states a 1.5V end-of-discharge for these cells. I have no idea how well they would handle recovering from 0V, but it would certainly be interesting to see!

2 Likes

Could you explain more about this?

2 Likes

They will absolutely be damaged but, like any li-ion chemistry, the voltage level and the time spent at under its rating determines the degree of damage. It’s cumulative so if it just happens once then there might be no noticeable effect. But if it keeps happening, or undervoltage for a long time, then the damage can get a lot worse.

Some chemistries can be less susceptible to this but I don’t know much about which are worse or better. If a cell has a low voltage cutoff rating though then going below it is not good for the cell.

If any cell could be brought to zero volts without damage then the manufacturer would make that a huge part of their marketing and it would be in the datasheet. It would make long term cell storage and shipping much easier and safer.

5 Likes

I think that all the components I’ve circled are dedicated to getting power and/or data across a voltage isolation gap, including that custom transformer ($$$).

Each module would need power and isolated data lines in order to talk to the “brain” for the BMS. Since each module is probably at a different voltage, in series, they would blow up the master controller (“brain”) if connected directly.

The Texas Instruments web site has good info on EV BMS systems as they have some very capable automotive BMS controller chips. You can go down a verrry deep rabbit hole with stuff like passing ISO26262 testing, being ASIL compliant, and other safety-related automotive stuff that these BMS’s need to handle.

7 Likes

Are there any numbers on these two big chips?

image

4 Likes

Yes, I’ll get you those numbers when I’m back into work on Monday. Thanks for all the info John! As always, your insights are invaluable :grin:

3 Likes

I’ll expect a dozen on my porch by Monday morning.

Don’t forget my cashew milk decaf Americano this time Benji or I’ll be leaving a rather scathing Yelp review.

(Seriously, what’s the ballpark on these? And since when did you become the village drug dealer?)

7 Likes

Do you ship to Iceland ?

2 Likes

If you plan to buy an EV battery, then no.

no idea about small stuff tho

2 Likes

grats on the job, that shelf of batteries looks like proper firehazard tho xD

dont load weight ontop of batteries in storage, ever (unless they’re specifically made for stacking). We’ve burned down one office doing the exact same thing you’re doing in the picture above. I’m not trying to be the asshole in the bunch here, but please please be careful.

5 Likes

It’s a long shot, but if you have batteries for Amazon Ring cameras, I could use a few… They’re so expensive and I feel crappy buying them right from Amazon.

1 Like

I totally missed the serious tag, sorry :pray:

1 Like


Rectangle chip:

SPF2011
SK 3626A

Square chip:

31421A00
R5F21368YK
FP

3 Likes

Thanks!

I appreciate your concern! Batteries can be very unsafe if not treated properly, and having a healthy respect for that is critical to any safe handling practices.

The units on top of the shelves in that first picture are empty battery casings (the metal shells that get bolted to the car chassis), there are no battery cells inside those. All of our battery modules and cells are stored properly, isolated and insulated on their own shelves (lower to the ground) :slight_smile:

The units that are stacked in the second picture on pallets are either full under-car-battery-sleds (therefore contained within a rigid metal shell) and only stacked according to their loading tolerances, or they are modules which are individually boxed or padded. There are also several empty metal shells strewn about, which confuses things even more since those dont require the same level of care that a battery does.

We have been doing this for a lot of years, and never had any battery fires or issues. We know what we are doing :grin:

5 Likes

Our current trade is mostly in large EV and hybrid battery packs, which we process down into battery modules for reuse or remanufacturing. High-volume low-margin stuff like small round-cell packs are less of a focus for us (at this time), but if we get any Ring batteries in you’ll be the first to know :wink:

1 Like