Homemade Battery Packs

DrkAngel said:
Latest project items 10s2p with EVE icr18650/26V are usable between 4.2V and ~3.3V but have a very broad and high energy density between 3.5V and 3.7V, towards 50%.

10A continuous BMS so will need to parallel ... 4 for max hill climbs. 36V 10Ah for daily use and 39.6V 20Ah for trips-n-such.

I just received 4 of these.
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They come in a 2x10 with a frame and shipped at 35.7V. No connectors. I added the XT60 and a charge plug.

The BMS has a temperature sensor. I think the port by the charge connector is for a LED display. One more connector in the middle, and some lind of reset button.

I also noticed that the LED flashes red when I connect the charger, and the charger also blips, so if it is charging, it's doing so in bursts/ However, I only have cheap chargers. I could charge thru the discharge (kaboom of the charger fails) , I guess.

I didn't realize that the BMS is 10A, and these are apparently 7.7A cells. A little light for ebiking. Guess I will wrap them with some rubber padding and shrink wrap them. Use two in parallel for a 20A controller. Makes for a $50 battery, Always fun.
 
Looks like these are not good for ebiking. The 10A max current is pretty weak. I put two in parallel to run with a 20A KT sine wave controller, and the packs reset whenever I tried to pull the 20A with throttle.

My next step is to remove the BMS and combine the two into a 10S-4P pack with a 25A BMS. IF that works, then I'll be happy.

I wouldn't recommend them. The charging is funky. with the charger being switched on/off. The LED starts flashing blue as soon as it drops off 42 volts which is irritating. FInally, they aren''t very robust cells. I could run the above bike easily on the older 10S-2P packs. On the other hand, the spec sheet says they have cut cells in half, squashed them and overcharged them with no fires.
 
I will likely cut tabs near white silicone, remove BMS, straighten and solder to 3 additional packs for 10s8p 36V 20.4Ah.
Might leave 1 BMS for balance only, definitely charging through output.
As proposed earlier, may trial as 11s8p charged to ~41V and cycle to 38.5V (3.5V-3.7V) for a near 10Ah capacity and, effectively, unlimited lifespan.
Perfect for at least 2 of my 250w geared hub eBikes.
 
I found two of latest battery hookup segway packs in parallel with the original BMS could not run my 500W ebikeling notor with 20A controller. The packs would reset, but with the BMS taken out, then two in parallel could push 20A. I pulled out about 4Ah riding around while the voltage dropped from 41V to 37V.

I went ahead and put a 25A BMS on it, which tested out OK on a short ride tonight. Sag from 42 to 39V under 20A draw.

Dremeled at the tabs and removed the BMS on two packs. Cut away the plastic on one pack so I could majke a thinner sandwich.
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Laid them side by side and glued them with Loctite contsruction adhesive. The next day, I soldered the leftover tabs on one pack to tie the parallel groups together. This was for balance, and not intended to carry current in the lateral direction.
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Attached balance wires. WIred up BMS. I did add two copper wire jumpers at the positive and negative ends of the pack to carry current laterally from the end contacts. Hey, it powers up.
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Next is to order some shrinkwrap and wrap wthe cells, with some padding.

In conclusion, It's like I made a pack out of laptop cells. It should be very safe though. The cells are in a robust plastic form. I've got a good balance BMS on it. BMS was $18. Two packs were $50. Add $8 for shipping.
 
Done. 10-4p 36V 10AH. 25A balance BMS. Shrink wrapped. Almost takes up the same space as a 10S5P and weighs 4.8 pounds.

I don't know how it will do for capacity. I'll be happy if it gives 8AH.It only has to provide 20A peak for my 500W ebke, and it will do that so it wasn't a boondoggle. About $75 and some time went into this. Wouldn't buy any more.


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docw009 said:
I pulled out about 4Ah riding around while the voltage dropped from 41V to 37V.

Using only 4Ah from 4.1V to 3.7V means your cells have excellent capacity!
You used less than ... (900/2550 =) 35.3% for 4Ah



That means you will have over 10Ah+ if cells discharged to 3.3V.
docw009 said:
I don't know how it will do for capacity. I'll be happy if it gives 8AH.It only has to provide 20A peak for my 500W ebke,
Though, I would recommend a 20Ah battery paired with your 20A controller to obtain near the tested 1C usable lifespan the manufacturer obtained in testing.
 
I intend on paralleling 4x 10s2p EVE battery "Bricks" for 36V 20.4Ah.Removing 3 BMS but retaining 1.
Single BMS will retain Balance function for the entire 10s8p and will be attached to Volt meter as fuel level indicator and problem notifier.
Battery output and charge will be from bare cells and meter output will be from BMS which will notify of any BMS fault, low pack voltage, low bank voltage, over heat etc. - By blanking meter.

Slowly delving into my other battery acquisitions:

Ryobi 18V 1.6Ah modules (14 of 20) are operational, will use with my multitude of Ryobi tools.

14x Ryobi 40V 2.6Ah (except 1) will be hardwired to bypass BMS for Charge and discharge. Will externalize to XT60's for paralleling into various applications. Including 36V 10.4Ah battery replacing 36V 8Ah SLA on mower, various eBikes(?) ... will find some applications! (Oops 1 additional has 1 bank, 2 cells, bad, save for spares)

40x LG 3s 2600mAh modules worked into NEW 33.3V 31.2Ah eBike pack (1kWh+), 12 spares-singles dedicated to eBke lights.

31x 8Ah 200A continuous LiPo. 28 for 14s2p 48V++ 16Ah for 48V 1000w rear hub build. 3 for 12V 150A spot welder.

I know, it may not sound like I've accomplished much ... but, planning can be as, or more, important than getting started fast.
 
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I didn't do it!

UPS on the store sign lights ... confused the Utility men.

"
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OLEAN — Firefighters battled cold temperatures as well as a structure fire on Buffalo Street Tuesday night.

Initial reports of a structure fire at 927 Buffalo St. were announced over the emergency scanner at approximately 7:20 p.m. Within minutes the emergency dispatcher was describing the building as fully engulfed.

As temperatures dipped into the teens, around two dozen firefighters from the Olean city and Allegany fire departments attempted to get the blaze under control.

The fire, which initially appeared toward the rear of the structure and along the roofline, later flared out near the roof at the front of the building and created a hole in the siding near ground level along the Sullivan Street side, despite the efforts of two engines and two ladder trucks on the scene.

A request was made for an engine from the Hinsdale Volunteer Fire Department to be placed on standby at 9 p.m.

According to Cattaraugus County Real Property, the property holds six units and is owned by Linda M. Barlett of 693 S. Union St. Walter’s Computer Plus occupies a storefront on the ground floor.

No further details were available, as efforts to combat the blaze were still ongoing at press time."

Got out with 2 laptops and my wimpiest electric bike ...
 
DrkAngel said:
Got out with 2 laptops and my wimpiest electric bike ...
does this mean it was your home?

if so, i offer my sincerest sympathies from experience, and hope that at least all people and living things got out unharmed.

what can we do to help?
 
amberwolf said:
DrkAngel said:
Got out with 2 laptops and my wimpiest electric bike ...
does this mean it was your home?

if so, i offer my sincerest sympathies from experience, and hope that at least all people and living things got out unharmed.

what can we do to help?
I second this... Holy moly! The address matches up with DrkAngel's stated location in new york.
 
Was allowed in for 45 minutes today, escorted by Code Enforcement.
Got:
5 eBikes, 2 old, 2 new & my Snow Beast - 1 Haro 700C pedaler
Geared Front hub ... still in box
A few more wet laptops
Most of my Ryobi cordless
4 USB back up drives
4 eZip packs
fistful of flash drives
31 HP 8Ah 200-400A LiPo
12 36V 5.1Ah Bricks
My Sales Receipts - for Sales and Income Taxes
my wallet ...

Hope I can get back in ... so much good stuff left !!!

Yeah ... was my business and home.

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Just received ... Suggested Facebook AD


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Fire Sale?
 
Landlord let me in through back door and pulled 4 more eBikes, plus a dozen good bikes, about a dozen good(?) computers and a massive amount of tools - Craftsman, B&D, Ridgid, DeWalt and, of course, Ryobi.
Found my wallet and surprisingly clean dozen pair of jeans, still folded in a box (from last laundry trip), a few pairs of Winter shoes. Will be attempting smoke abatement with Vinegar soak then wash with baking soda added.
Red Cross helped with some funds then referred me to Social Services. Easy to sign up, except, as a business owner I have a business account with collected NY Sales Tax ... which SS decided was "expendable funds" making me ineligible for assistance. I told them they had better confer with NY Tax Department before they force me to really screw myself (NY is jealous and vindictive on their Tax collecting!).
Searching found availability of "Tax Pre-payment" for Sales Tax and indicated form ST-330, but, of course Sales Tax forms did not list any form ST-330 and "search" on the Sales Tax page showed "no results", got frustrated and took me several tries, over different days to find it's unlisted location. Finally got it filled out and and cleaned out the Business account ,,, documented and provided to SS along with NY driver's License, "proof of address" (old and "none") and may receive assistance after processing and approval.

But, in good spirits, temporary lodging with a friend in government subsidized Senior housing, (female) Manager wishes "oh so much" that I was 1 year older and qualified to move into an apartment. Had 3, communities leading citizens, help me move 4 trucks of recovered items into storage (bikes are bulky) ... volunteering at Food Pantry and Community Garden really paying off. Finally enrolled at food Pantry and received a goodly amount of healthy, (but still edible, and tasty, food).

With 1 year till early retirement, I won't be re-starting a computer business, but will service my loyal customers. Social Services did not ask me to sign up at Job Service, but will need to get some job, need to do something besides siting on my butt, riding eBike and playing in the Garden. Will be taking advantage of Medicaid to patch up the old body!

Of course, I will continue to build eBike batteries and eBikes!
PS found 5 mid-drive compatible cranks I bought and forgot about!
 
j bjork said:
Is it known what started the fire?
Not Me!
Not Lithium related.
Rumors are illegal activity.
Upstairs Apt owner complained to Police that there were people in his apartment and he wanted them out!
Destroying evidence because Police were informed?
Meth lab?
 
Sorry for the lost. I had a fire in my garage on the first floor I live on the third. Got down looked across the street and my roommate was there talking to neighbors. He forgot about me. Then the looters how do you say looters as they come in waves and see if fire and if they think they should just find some in your fire. Good luck keep your eyes out.
 
Some of my 10s2p Samsung 22p Hoverboard packs suffered moisture damage corrosion-rust, will have to separate and re certify cells.
Got 10 of 12 new 10s2p EVE bricks still in perfect shape ... time to do some more building!
31 8Ah 200-400A Lipo cells intact. (48V 750-1000w rear hub recovered in perfect shape)
Getting settled and sorted, expect to have plenty of spare time for experimenting.

Snow Beast has batteries dried and tested, but sadly, got hooked on car during the snow and slush, over the last couple weeks :cry:
 
Curious if anyone else would recommend tinkering with those 40V ryobi packs to make a larger storage pack. I'm kind of torn between the power tool hot swap convenience versus an enclosed, well weather proofed system. I would be putting this in what is essentially a toy (mx650) so not loads of real estate....

Seems like this would be a low level investment to start with potentially.
 
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