Molicel P42A, Sony/Murata US18650VTC5D in 14s5p battery packs sounds like a good deal?

[floydr]

Anyone looking for Molicel 2170 INR-21700-P42A cells already in a 14s5p battery $99.99

https://batteryhookup.com/products/new-48v-18ah-907-2wh-14s5p-2170-lithium-ion-cells

or
Sony/Murata US18650VTC5D cells in a 14s5p battery $60

https://batteryhookup.com/products/new-48v-12-15ah-612-36wh-14s5p-18650-lithium-ion-cells

These both look to be a good deal.

I will post an update when I get the packs I ordered.

Later floyd

 

[thebes]

I also ordered some of these packs, 6 to be exact, was just too good of a deal to pass up, $1.4 per p42a. These also, according to some people whove already received the packs, test up to the rated capacity, right between 4100 and 4200mAh per cell at 1 amp discharge, really amazing!

They also appear to be really easy to tear apart which is a positive. Ive got no information on the bms though seems to be completely proprietary.

Also for anyone curious these appear to have come from a mech robot suit type thing called the "XO" and if I had to guess these packs were being liquidated after Sarcos rebranded to Palladyne AI.

 

[gobi]

I received my order today,
these packs are very very very long and bulky, as is, they are NOT usable.

My sarcos pack came in with what appears to be a dead BMS (hibernating?),
when I press the switch, I do not get any light.
Checking each bank I found them to be at 3.55 to 3.53 v

I have not figured out how open it up further to a peek at the bottom and the pack.

keyword: sarcos, robot Molicel 21700

 

[thebes]

The bmses appear to be completely proprietary and I would assume that without a decent amount of reverse engineering theyre just worth their weight in scarp. I doubt that that button is for enabling discharge, it is more likely a 'clear state' or something along those lines used for testing or validation. Would be more likely that the pins circled in red are used for enabling/disabling discharge or are some other type of communication between the bms and the system they were attached to. Could be as simple as shorting one of them to ground or as complicated as a canbus or a uart protocol. Hell it could be some completely proprietary protocol too...


Also an update on my order, ended up ordering another two packs, totalling eight now, and tracking lables have been created for both but neither have had a package dropped off yet, fingers crossed theyll arrive sometime later this week!

 

[999zip999]

I received my order today,
these packs are very very very long and bulky, as is, they are NOT usable.

My sarcos pack came in with what appears to be a dead BMS (hibernating?),
when I press the switch, I do not get any light.
Checking each bank I found them to be at 3.55 to 3.53 v

I have not figured out how open it up further to a peek at the bottom and the pack.

keyword: sarcos, robot Molicel 21700

Looks great I want it some but I have three batteries in the garage I'm not using right now.

 

[999zip999]

Yeah it's my kind of battery I have those in a NESE kit in a MTB just needs the handle bar stuff.
If I need a 80amp battery I build a 160a battery for I think lower I believe resistance and able to pass the electrons back and forth easier and should last longer without the load or the heat in let's say 100 amp battery for an 80 amp controller.
Just about hanging out in this thread maybe Floyd wouldn't mind if we step all over his thread about batteries. ?

 

[floydr]

Hang out as much as you like. I received my 2 packs today too. I have had the cover/handle off looked at the BMS, decided I will wait till tomorrow before I dive into the tear down/ attempting to get the BMS to work.
later floyd

 

[gromike]

I bought one for $99.99 on Saturday. Today the battery is $110, so they must be selling well.

 

[thebes]

I bought one for $99.99 on Saturday. Today the battery is $110, so they must be selling well.

Yeah very...they sold ~500 units just on friday, also for anyone curious as of right now theres 192 molicell packs left in stock and 17 sonys, will probably last another day or two for anyone else interested in buying one.

 

[floydr]

I removed all the screw from the sarco battery BMS, cut the wires from the pads to the bms, unhooked the three thermistors, only thing still holding the BMS on is a 5 wire connector near the center of the board and the main negative and main positive connections to the BMS. I got the BMS to flex about a 1/4 inch on either end. Might have to cut away the plastic to expose the cells I really don't want to might be the only way unless someone more patient/smarter than me figures out a way to activate the BMS/ remove the BMS without destroying the case. maybe @gobi had better luck than I am having.
Later floyd

 

[gobi]

Floyd,
I was procrastinating while you took a stab at it

I really have on use for the batt/cells now, just bought it cuz it was cool, I want to be able to use it as is if possible.
Yes, we should be able to reverse engineer the bms.

My electronics chi is very low due to a decade of changing diapers and related tasks of being a single dad, I am not very well experienced in recognizing surface mounted components off the batt. I usually look up the chip number and read the spec and figure out what it does.

Problem 1 - Looks like Sarcos put some kinda paint/epoxy of the chip surface to HIDE the numbers before they applied conformal coating. The conformal coating looks like it was hand applied, makes sense as these are sample units for their prototype probably.

My girls have a UV flash light and a USB 40x microscope, would that help in reading the numbers?


I see 2 large chips which are probably the controller chips, from reading on EEVBLOG, here and other most BMS now use a controller chip which voltage sense and puts the bms in sleep mode and other functions that can be programmed.

Question - Can anyone identify the 2 rectangular chips marked Items 1 and 2 in the pics below?
TI MCUs are square shaped, from what I have seen in other battery bms with advanced features.

Switching + pole -
3 sets of 8 pin mosfets are used to switch the positive pole.
why 8 pin mosfets?

1st bank is switch via a NTC, I am guessing that is the thermal protection bank

2nd ? (witch craft?)

3rd bank ? (batt/cell voltage switched?)


Physical construction:
Looks like there is some GLUE at the bottom holding the batt module to the bottom of the case, I too took off all outer screws once the I took off the top.

I was expecting the batts unit to drop off the case once I inverted it, but no dice,

I used 2 screw drivers to pry at the edges and I got the negative end to come up few mills and heard a loud crack.

Charging:
I did not see any charging ports, so I guessing the discharge ports are used to charge these.

5 pin connector:
My 5 pin connector is covered in some yellow glue, pretty nasty hard stuff, I tried to scrape it off with my manly nails, no dice.


Request: Floyd, if you are going destroy the bms, could you do me a fav and scrape off the glue around the 5 pin connector and take a pic pls.

 

[gobi]

what component are these?

 

[gobi]

8 pin mosfets, 3 banks of them