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

I need a bigger solder iron!
docw009 said:
I had a massive iron used to build a leaded glass lamp many years ago.
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How many watts is that monster? Makes my 150 watt iron look like a toy.

I think on my other three batteries I will just remove the BMS and install BT BMS's
later floyd
 
floydr said:
I think on my other three batteries I will just remove the BMS and install BT BMS's
later floyd
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Oh no! Someone has got to figure out the installed bms.
I plan to keep the battery intact. It would be a plus to be able to use the battery case, as it is sealed up pretty good and almost waterproof. I don't think one can find a 100a bms that would fit in with the top of the case installed.
 
small update at the risk of possibly being redundant, was able to scrape the conformal coating off but not scuff up the ics in the process

1715307550431.png

1. is a bq8050
2. is an rtc by the name of PCF85263A with i2c integration
3. best that I could see the text reads "ath230 2eclp 223ousa" could not find any reference to it apart from a taobao link with 0 information and some other sketch listing for it

hope this helps someone out
 
I don't know if you helped me out, or led me down a rabbit hole.
But thanks.
I am willing to spend some effort in figuring this battery out, with some help of those fluent in modern electronics. If I can have a functional battery in this battery's case it's a win for me.
I'd like to have a battery for an eboat conversion. A 48v battery, capable of up to 100a that will power a trolling motor would be a sweet spot for me.
 
gromike said:
I don't think one can find a 100a bms that would fit in with the top of the case installed.
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The ENEPAQ tiny bms150A/750A is only 95x65x9 mm. would just fit between the plastic side pieces 5 mm of depth there plus the lid has at least 5 more mm of space. A bit of trimming on the plastic would get you more room for the Bms Of course it is the price of 3 or 4 100A BT bmses. Glad I bought mine years ago before the name change. It has been waiting for a project.
It will go on the first battery. This is the only smart BMS I am aware of that might work.
later floyd
 
Ouch! That bms ain't on no Amazon, Alibaba, etc. Though DigiKey has it for $389. That's almost 4x what the batteries cost initially.
I think I'll wait and see what people do with their batteries for awhile before I rip out the installed bms.
 
I am waiting too, but the first battery I removed the BMS already. So it will get the tiny bms. No way would I spend what they cost now, There are the bms's from MAXKGO, your battery management expert and ENNOID which appear to be small and as simple or complex as you want.
Later floyd
 
With a BF soldering iron, you can remove the solder in the center w/o damaging the BMS. The two end points were actually easy with just two blades, but I didn't know the middle points were 1/4" diameter braided copper wire. First, I thought there were two screws under the solder. I eventually drilled out most of the wire, bot knowing what it was, except that it was soft,

If I had known what they were...First remove all the screws. Cut the glue around the center JST and use a pliers to pull it off. Remove the three TC plugs. Clip all the balance wire bonds. Then unsolder each of the two ends. The BMS should lift enough to clear the prongs, Now with enough heat, soften the solder on one braid and lift that side of the board. Repeat on the other. Of course, you'll never get the braided wires back in those holes.

If someone were to release the comm protocol, I suppose you could rig up an Arduino to talk the the BMS and turn it on. You could probably read the voltage on every bank too, I have an Arduino hobby kit, but I ain't foing to be doing that,
 
docw009 said:
If someone were to release the comm protocol, I suppose you could rig up an Arduino to talk the the BMS and turn it on. You could probably read the voltage on every bank too, I have an Arduino hobby kit, but I ain't foing to be doing that,
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Nathan Seidle of Sparkfun has some code for the bq76940 on Github:
GitHub - nseidle/BMS: Breakout board for BQ76940 Battery Monitoring System

Also, the LibreSolar project:
GitHub - LibreSolar/bq769x0-arduino-library: Arduino-compatible library for battery management system based on Texas Instruments bq769x0 analog frontend (bq76920, bq76930 and bq76940)
 
I got the cells out. Removed the wire bonds and plates. Removed the screws holding the plastic enclosures together. The cell holder has an open area which allowed me to cut it into two sections..

I placed a small vise inside, between the top and bottom plastic pieces. Opened the vise, and the sections spread apart. I was going to do this with jam nuts but the vise worked, Cells were just held with a thin layer of rubber goop. Wasn't too hard at all.

These things are dangerous without sleeves. My watchband touched a bare end and shorted out. Got hot. I've got plastic washers and shrinkwrap sleeves coming in.
 
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As for me, I have 2 of these batteries. I don't want to break them up as they are built better than anything I could ever do, and at a 100 amps, at 48 volts, it will do more than anything I would want. But the pack is too big for any bike that I personally know. If I could get one of those Kawasaki Noslisu front-loading tilting cargo trikes I would find a place for it, and a 1500w Leaf motor with an 80 amp controller! Otherwise they will power an eboat. All you got to do is buy a 48v trolling motor! Wire it up and you're good to go.
It would be sooo nice to have the batteries in the OEM case, and plugged in to the OEM connectors. I would assume those to be "water proof", as is the battery case.
 
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docw009 said:
I took off the cover and found mine was at 49.2V, with cell voltages at 3.52 volt,. So I didn't get low cell groups.

I couldn't find any hidden screws on the bottom of the case. Nothing under the label, I figure these round circles are where bosses were molded into the case? How did you guys get the cell assembly out? They're not held in with tape are they? That would not be very robotic.

View attachment 352423
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The metal blades where the battery connects to the robot is what's holding it in. I used a pry bar to pry them down through the slots and then worked it slowly out pry on the corners. I ruined the blades though.
 
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I pulled the batteries out of the 2 packs I bought.

1000009580.jpg

These are molicell batteries? Are they missing the sleeve that is normally wrapped around them or is there some sort of metal shell over them. It's so easy to short this battery out.

Can I clean the old welds off and spot weld onto these?
 
Mine were marked LAA9M40702. I beleive you skip the first 4 letters. M would indicate 2022, 407 is April 7, and sequence 02. No worry there. I've got new cells I bought in 2020 that I've yet to use.

I've seen a lot worse than those little wire bond remnantts. I plan to spot weld over them.

I recommend the plastic washer for the positive end, plus a 21700 sleeve wrap. I ordered both from imrbatteries.com, and won't be working with mine til they arrive,
 
floydr said:
Anyone looking for Molicel 2170 INR-21700-P42A cells already in a 14s5p battery $99.99
or
Sony/Murata US18650VTC5D cells in a 14s5p battery $60
These both look to be a good deal.

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

Later floyd
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I live 3 miles from that place and just got 3 Molicel packs myself
 
floydr said:
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
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Well, I got some courage, removed the 100a fuse and cut the BMS board at both ends right before the positive and negative terminals with a Dremel that had a cutting wheel attached. I was going to crap myself the whole time doing it. I then trimmed off the balance terminals. I am alive and no sparks too. lol. BTW, I am no way shape or form recommending anyone to do this for the record, im just saying that what I did. My cells were all right around 3.5v's. I rigged up a temporary BMS to monitor, balance and charge the cells. So far , so good.

My next questions to move forward with this pack are in this post.
endless-sphere.com

Have new battery packs that I am stripping the proprietary BMS and adding one that is capable of more amps. What do I need to look out for?

got an incredible deal on battery packs, brand new in the box from a exoskeleton robotics company that went out of business end of 2023. Got these packs for $100 a piece local pickup (www.batteryhookup.com). The batteries packs were manufactured in Sept of 2023. They are a 14S5P config and...
endless-sphere.com endless-sphere.com
 

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docw009 said:
I took off the cover and found mine was at 49.2V, with cell voltages at 3.52 volt,. So I didn't get low cell groups.

I couldn't find any hidden screws on the bottom of the case. Nothing under the label, I figure these round circles are where bosses were molded into the case? How did you guys get the cell assembly out? They're not held in with tape are they? That would not be very robotic.

View attachment 352423
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No easy way that I found. I made a mess trying different ways. Not recommending this, but fastest way was when I used a small circular saw with about 1/8in of the blade exposed. If you go this route you will have to start out real small, like 1/16 exposed, try it, and see if it just barely clears through the shell, in not, keep adding just the slight bit more till it does. Then zip away around the perimeter
.
 
thebes said:
Ended up leaving it connected for a good couple minutes, should have been adequate for any delay or timer

nope, nothing seemed to change as far as I could tell

What I didnt think to check is as to whether the pins are atually providing 3v/5v with a multimeter, shouldve been the first thing I tried 😅

Also why charge the cells up to specifically 53v? curious as to whether there is any specific thing referencing 53v/~3.7v per cell (havent read the posted ti datasheet/manual yet) or if its just a hunch 😆


best method I found is to break the bms in such a way so you can get to this point
View attachment 352477
which then provides enough clearance for wire snips to reach the 6 guage and you can cut the remaining parts of the bms off
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I used a Dremel with a cutting wheel to slice right before the end terminals.
 

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docw009 said:
This is was the good part. The cells are wire bonded, and the wires may double as fuses. Another BMS could be attached and this ought to be one pretty stout battery. If one were looking to recover the cells, there's no nasty spot welds to rip out.
View attachment 352488View attachment 352489
I don't have a use for a 14S pack this big. Probably just take out the cells and make mini packs.
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This is one of my questions about the wire bonds and terminal ends. I know a Molicel 14s5p setup is capable of a good 200amps or more. However, can this pack with the BMS replaced withstand that?
 
vengox said:
This is one of my questions about the wire bonds and terminal ends. I know a Molicel 14s5p setup is capable of a good 200amps or more. However, can this pack with the BMS replaced withstand that?
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Im guessing that the cell fuses pop at 20 or 25 amps as the main fuse is rated for a hundred amps, 100/5p = 20 would be being drawn from each cell at the peak, more likely that its 25 or maybe even 30 so the margins arent as slim.
 
I'm not ready to pull the bms off my 2 packs yet. This battery is so much a better design than any battery I have opened up. They must of cost Sarcos a couple of thousand a piece. And speaking of Sarcos, what else are they liquidating. I would really like to find the battery mount base, even if I put in another bms in my batteries.

Their exoskeleton robot thing was stupid, in my opinion, with extremely limited uses. How many customers are going to sign up for a $100,000 per year for something you can do with a small tractor. Maybe the Pentagon, but I guess they took a pass.
Battery Hookup must of bought something like a thousand of these batteries, so there must be a lot of other leftover exoskeleton parts in liquidation somewhere.
 
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gromike said:
Battery Hookup must of bought something like a thousand of these batteries, so there must be a lot of other leftover exoskeleton parts in liquidation somewhere.
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There might be a chance that someone at Batteryhookup has a lead on those exoskeleton parts, I have called them before and they seem friendly and helpful.
 
Anyone making any progress on figuring out how to turn on the pack's installed bms, or has anyone installed another bms on this battery?
I'll probably pull the bms off and install another one. So that begs the question, which bms? Maybe something like this:

6S-21S Smart BMS 100A-200A – XiaoxiangBMS

xiaoxiangbms.com xiaoxiangbms.com
 
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