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Re: Homemade Battery Packs

Posted: Nov 25 2018 4:40pm
by DrkAngel
Index
DrkAngel wrote:
Nov 05 2017 7:55pm
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...
25.9V 26.4Ah #1 finished

7s12p Samsung cells are capable of 120A continuous 240A surge but controllers are <30A and installed 40A fuse (trying new 58V fuses & holder)
Just finished 1, had to test drive it ... rain stopped for awhile.
No BMS installed! Turned out were only 20A continuous.
Mostly worried about parasitic draw when customers let set for the Winter.

Image

10s2p Bricks disassembled into 8s2p + 2s2p and I was oh so tempted to build as 8s12p ... but needed for 24V bikes and I already have the 7s chargers.
Image

25.9V 26.4Ah #2 nearly complete
Just need to run the parallels and power rails and install fuse.
Entering it's 2nd year, and Winter, these Samsung cells are performing excellently.
Most markedly, #1 build maintains equality within 2/100ths V at near empty discharge.
A testament to genuine Samsung icr18650-22p!

Tested at 14ºF and still outputs good Voltage-amperage.
.

Re: Homemade Battery Packs

Posted: Nov 25 2018 7:47pm
by DrkAngel
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...
Updated Lithium Chemistry Chart
Li-Chemistries.jpg
Li-Chemistries.jpg (64.02 KiB) Viewed 3605 times

Link to full Article
- descriptions

Re: Homemade Battery Packs

Posted: Nov 26 2018 6:22am
by docware
DrkAngel ,
thank you for our yesterday´s conversation. I became interested in Li-ion cell just in summer 2017, so cells like Sanyo GA, LG MJ1, Samsung 30Q, … are for me really normal. Not realizing that in fact it is currently „state of the art“. So looking at these modern cells, I still didn´t uderstand, why recomended storage voltage is 3,8 V. After our discussion I have made conclusion that 3,8 V was valid few years ago and for mentioned modern cells we can use lower storage voltage 3,5 V. Just we have to know what cells are in our battery and use storage voltage accordingly. If we don´t know the cells type, then to be on the safe side, we should use storage voltage 3,7 – 3,8 V. Any comment about my conclusion ?

Re: Homemade Battery Packs

Posted: Nov 26 2018 8:55am
by DrkAngel
I mentioned storing my older cells @ 3.85V, 3.65V for my newer chemistry Samsung and determining optimal voltage range for any cell type and storing at the 20-50% capacity voltage.
Insuring , of course, that optimal (usable) voltage is determined at static voltage - Some manufacturers discharge graphs show discharging to 2.80V, however , this is during discharge and actual cell voltage recovers to, and is actually, 3.2V, 3.4V or even 3.6V+
Actually discharging any cell to a static 2.8V is damaging and dangerous!!!

How to determine optimal usable voltage and therefore reasonable storage voltage?
Manufactures specs - most reputable manufacturers produce a discharge graph, lowest rate discharge line usually demonstrates a cliff where voltage drops drastically, this indicates near minimal "usable" voltage.
Independent tests - Best Test Site!
Shipped voltage on new - law requires all cells-batteries to be shipped charged at 30% of capacity! - excepting batteries shipped with\in device. (measure voltage before 1st charge!) High, and low, voltages considered a danger risk!
"Safe" voltage for Unknown - 3.80V

Most recent RC LiPo purchases - voltages shipped at:
#1 batch shipped at 3.81-3.82V per cell
#2 batch shipped at 3.84V per cell
Indicates LiCo02 chemistry with ~ 4.20V - ±3.60V optimal usable voltages

"New" cells received with more than a minor variance in cell voltages should be considered "suspect" and in need of thorough testing or return.

Re: Homemade Battery Packs

Posted: Nov 26 2018 11:52am
by Philaphlous
For those of us that are using the 18650 battery spacers...are you gluing the cells into the spacers or just leaving the cells in loose?

Re: Homemade Battery Packs

Posted: Dec 06 2018 10:43pm
by Matador
FROM HOOVERBOARD PACKS of AlarmHookup.... Remasterized the cells...
Total cost 180 USD (including all, even the kapton tape, connection, cable, connectors, BMS, cell holders and cells...).
See whole build here (with casing) :https://endless-sphere.com/forums/viewt ... 5#p1412338
r.jpg
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s.jpg
s.jpg (441.54 KiB) Viewed 2496 times
Specification are:
14S4P of Samsung MF1 (2150mAh, 10A);
Capacity : 8.6Ah
Max discharge : 40A (cell specs) ; 45A (BMS - continous rating)
Nominal voltage : 51.4V (3.67 V)
Max voltage: 58.8V - Min voltage : 38.5V (BMS LVC of 2.75V)
Chemistry : NMC - LiNiMnCoO2
Internal resistance : 125 mOhm DCIR measured (after the BMS when applying 12.8 amp load): Net equivalent of 36 mOhm per cells (including the effect of added BMS and connector resistance).
BMS: 45A continuous; 200A; balance current 60 mA
Cell connections: Through top grade pure 0.127mm thick copper sheet, soldered with 140W iron
Cell specification samsung MF1:
LG MF1 (hoverboard).pdf
(445.44 KiB) Downloaded 52 times
Matador.

Lithiumization or Ni-Cd Rejuvination?

Posted: Dec 23 2018 7:40am
by DrkAngel
Almost embarrassed to note, here ...
Sorting through my piles of garage sale cordless tools, looking for items worthy of lithium upgrades. Found Ryobi 14.4V VSR drill and light (Blue - old models) in large plastic case. Both Ni-Cd batteries at empty and would not charge.
So, decided to "shock them up" as a rejuvenation method, figured not worthy of Lithiumization ...
Standard recommendation is shocking at 200% rated voltage, closest I have are my 36V hoverboard packs, so I paralleled a pair and and sparked 41V voltage into the Ni-Cd battery terminals. Several brief contacts then a single 2-3 second contact. Supposedly melting-burning dendrites that short cells or cause self-discharge.

1 week later, cells are maintaining good voltage and I have a good drill and light set that I will never use ... damn it all!
16.8V 2A Lithium charger - $3.89

6-24V 3w LED -$2.98

Similar 12V Ryobi set
Shocked with 24V SLA and successfully rejuvenated 1, of 2, battery packs.
Drill and light look like new, so might Lithiumize. Will integrate 3s 2A charger into oem charger body.
12.6V 2A Lithium Charger -$3.98
Will go LED upgrade on light.
4-12V 3w Flashlight bulb - $2.73

Re: Homemade Battery Packs

Posted: Mar 09 2019 11:27am
by DrkAngel
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...
Spring?

Time to get ready for Spring!
I have about 5 batteries and a couple+ bikes to get ready for "the road".

Batteries
Summer weight (Laptop cells)
Test and balance check
25.9V 25.92Ah (2014 build - laptop lipo)
33.3V 31.2Ah MaxCell 1kWh (NOS HP laptop cells)
10.8V 25.9.Ah Wheelbarrel battery (will add 12V (3s) 40A continuous BMS)
25.9V 34.56Ah Mower battery needs 1 bank replaced ... the last add-in bank from lesser cells ... :oops: ...
(May add 20A continuous 50A cut-off BMS ... and will monitor for BMS parasitic draw!)

HO (High Output) 36V 4.4Ah Hoverboard batteries and various builds therefrom ...
25.9V 2.64Ah eZip build
cordless power tools 18V 4.4Ah Lithium rebuilds from Ni-Cd packs etc

Will also build 7.2V & 10.8V Laptop Lipo for 6V and 12V Florescent lanterns. (not worth converting to LED)

Bikes
Still need to correct motor wheel spoke holes on 2 eco-ride eZips. Spoke holes too small-tight forcing nipples to be straight >> which causes a severe bend of spoke at nipple >> causing excessive stress >> causing spoke breakage!
Will wrap 22ga insulated wire around spoke intersections to stabilize, remove all nipples, re-drill all rim holes slightly larger, re-insert hub and spoke assembly back into rim, tighten and true!
Front forks are Disc brake capable, so will outfit, at least 1 with Disc brake and may upgrade controller for ≤ 50V battery.

Clean-lube-tune-up, new pedal chain and, possibly, new quiet motor from eco-ride, for my 2013 Comfort Cruiser (near 12,000 miles ... so far)

Better get started!

Oh! Bought an eBikeling 500w geared front hub for a 24spd mountain bike last Summer and never took it out of the box ... better do something with that?

Re: Homemade Battery Packs

Posted: Mar 09 2019 2:08pm
by LeftieBiker
If you want a sharp-looking ride I can make you a deal on my black diamond frame Trailz. Only about 2k miles on it, and quite a few accessories, plus a 20AH Ping pack. See my post in the Trailz topic.

Re: Homemade Battery Packs

Posted: Mar 09 2019 5:19pm
by DrkAngel
LeftieBiker wrote:
Mar 09 2019 2:08pm
If you want a sharp-looking ride I can make you a deal on my black diamond frame Trailz. Only about 2k miles on it, and quite a few accessories, plus a 20AH Ping pack. See my post in the Trailz topic.
Got 2 of 'em already.
eZips
2 - Black Diamond frames
2 - Blue Diamond frames
1 - Silver Diamond frame
2 - Red Diamond frames
1 - Blue Step-through frame
iZip
1 - Mountain Trailz AL

+ 3 Hub Motored ...

Re: Homemade Battery Packs

Posted: Mar 09 2019 6:38pm
by LeftieBiker
DrkAngel wrote:
Mar 09 2019 5:19pm
LeftieBiker wrote:
Mar 09 2019 2:08pm
If you want a sharp-looking ride I can make you a deal on my black diamond frame Trailz. Only about 2k miles on it, and quite a few accessories, plus a 20AH Ping pack. See my post in the Trailz topic.
Got 2 of 'em already.
I have four. ;-) Plus two new bikes that I actually ride.

Re: Homemade Battery Packs

Posted: Mar 10 2019 9:19am
by DrkAngel
.
...
Expounded
DrkAngel wrote:
Mar 09 2019 11:27am
.
...
Spring?

Time to get ready for Spring!
I have about 5 batteries and a couple+ bikes to get ready for "the road".

Batteries
Summer weight (Laptop cells)

Test and balance check

25.9V 25.92Ah- (2014 build - laptop lipo) One of my most durable-reliable builds, built from NOS Dell Media Bay battery LiPo cells of 2008 vintage. Used for 5 years and thousands and thousands of miles ... so far. Did add, tacked on 1 18650 cell to slightly weaker bank. Nope, no BMS!

33.3V 31.2Ah MaxCell 1kWh (NOS HP laptop cells) - Barely used 2018 build. 36V Hoverboard batteries made this nearly obsolete. but will use for a bit of extra speed (23mph±) or extended cruising at partial throttle. (estimated range 40 miles+ @ 20mph ... 60 miles+ @ 15mph)

10.8V 25.9.Ah Wheelbarrel battery (will add 12V (3s) 40A continuous BMS) - Unregulated usage from different users results in intermittent-negligent charging, making BMS protection a near necessity.

25.9V 34.56Ah Mower battery needs 1 bank replaced ... the last add-in bank from lesser cells ... :oops: ...
(May add 20A continuous 50A cut-off BMS ... and will monitor for BMS parasitic draw!)

HO (High Output) 36V 4.4Ah Hoverboard batteries and various builds therefrom ... - Snow Beast uses 3 x 36V paralleled for 13.2Ah. Vintage WE 600w front hub build alternates between 2 x 36V for 8.8Ah and 4 x 36V for 17.6Ah (will likely transfer WE front hub to Mountain bike with dual brakes of drop to 25.9V Lipo and put on trike or rebuild into 20" and mount on rear of BMX, removing crank and adding foot pegs and full seat ... for the smaller grandkids, think I have a 24" disc brake wheel-fork I can add.)

25.9V 2.64Ah eZip build - great Samsung-22p cell build that ran great last year and during clear road Winter. Does good in the cold, but great when kept warmer.

cordless power tools 18V 4.4Ah Lithium rebuilds from Ni-Cd packs etc - will just test for maintained good balance

Will also build 7.2V & 10.8V Laptop Lipo for 6V and 12V Florescent lanterns. (not worth converting to LED) - yes, 6V Florescent lanterns run just fine and seem durable running at 7.2-8.4V Lithium. (2 examples)
Decided to explain a bit more-better.

Miles per Kilowatt hour at various speeds

Posted: Mar 14 2019 10:20pm
by DrkAngel
Hit 60ºF+ today and was testing batteries\bikes, Tried 33.3V on my 25.9V Comfort Cruiser ... "cruised" up to an exhilarating 25mph. At 1kWh will provide 60 miles @ 15mph, 40 miles @ 20 mph and 30 miles @ 25mph.

EBike Simulator rates 1kWh battery at:
15 mph = 76 miles
20 mph = 51 miles
25 mph = 35 miles
30mph = 20 miles (reapportioned battery, higher volts-lower amps)

Re: Homemade Battery Packs

Posted: Mar 17 2019 12:31pm
by DrkAngel
Oh boy! ...
Found 3 more boxes of Dell Laptop LiPo.
10.8V 4.32Ah from 3s2p packs. Hundreds of packs should provide good 1000+ cells. (All packs that would not maintain good charge were discarded years ago.)

Need to finish off the rest of this last batch, Lawnmower batt repair, fluorescent lanterns, maybe inverter or auxiliary UPS pack?
Image

Set aside a 15 pcs pile of NOS for 25.9V 25.92Ah eZip build.
Will need to test and rate them all ... next lousy weather project? I have 4 x 4 bay chargers for the oem Dell packs.
Charge them all up
Open and test all for full and equal voltage - label
Let set several days - test for any self-discharge, set aside failures!
Run a discharge and meter for voltage sag of pack and cells , set aside any with uneven or excessive IR
Gang cells as 30s for discharge test through 2 x 60w = 120w light bulbs for a 1 Ah per hour discharge
Discharge for 2 hours (2Ah) and label each cell pair with residual voltage
Build batteries with banks of best-equal residual voltage

Save good, but lesser capacity, cells for large bulk packs etc.
Separate and individually test cells from packs that failed self-discharge or unequal voltage, for ... ?

Re: Homemade Battery Packs

Posted: Jun 09 2019 9:52am
by DrkAngel
Had a wire malfunction of my Volt-Amp-Watt meter ( - no battery level indicator ) and accidentally discharged 2 paralleled Hoverboard batteries to near 30V, (3.00V per cell) - Yes the LVC ( Low Voltage Cut-off ) worked
So, I separated and did a 2A metered charge on each to measure capacity.
BMSed 36V 4.4Ah Hoverboard batteries (Samsung 22p cells) charged to precisely 42V
Batt #1 4.00Ah
Batt #2 3.97Ah
Still at 90% capacity and within 1% of each other after 100+ cycles being "abused" with 28Amp controller and discharging at 2-3C.
Yes, this does go against eveyrthing I have recommended! But was supposed to be just for trial ... and 2 batteries & controller fit so nicely in small camera bag hung from handlebars ... :oops: :oops:
Will Quad with another pair on next variant to prolong life and range.
( Been running Vintage WE BD-36 600w front brush hub on Schwinn Candis cruiser )

Re: Homemade Battery Packs

Posted: Jun 29 2019 10:09am
by DrkAngel
Well, not exactly a "homemade" battery, just a simple and substantial upgrade to an old SLA battery.
Picked up an abused Watseka XP of 2015-16 vintage and decided it worth a rebuild.
Got most everything functional so needed a battery to test drive with.
Pulled 3 8Ah Lead bricks and dropped in 3 36V 4.4Ah (13.2Ah) hoverboard batteries.
(Soldered XT60 connector into battery shell for simple connect)


Image

About 1/3rd the weight and possibly 300% the (usable) capacity ( 5 - 10x the expected lifespan, if I moderate the charged voltage to 41V? )
Motor is a wimpy 250w so battery has decent run time.
Packs positioned with Styrofoam then added 2x rolled bubble wrap and squashed shell closed.
Build is temporary, dependent on eventual disposition, sell or keep. Could fit 20Ah++ in shell.
Battery meter (6 LED) might work well with saggy SLA but still reads full when Lithium is near 36V, fortunetaly, Samsung cells are empty near a static 3.4V, so there is some indication. Might replace meter with a "proper" LCD volt meter?

Watseka XP rebuild thread

Re: Homemade Battery Packs

Posted: Jun 30 2019 7:26am
by DrkAngel
DrkAngel wrote:
Jun 29 2019 10:09am
Well, not exactly a "homemade" battery, just a simple and substantial upgrade to an old SLA battery.
Picked up an abused Watseka XP of 2015-16 vintage and decided it worth a rebuild.
Got most everything functional so needed a battery to test drive with.
Pulled 3 8Ah Lead bricks and dropped in 3 36V 4.4Ah (13.2Ah) hoverboard batteries.
(Soldered XT60 connector into battery shell for simple connect)


Image

About 1/3rd the weight and possibly 300% the (usable) capacity ( 5 - 10x the expected lifespan, if I moderate the charged voltage to 41V? )
Motor is a wimpy 250w so battery has decent run time.
Packs positioned with Styrofoam then added 2x rolled bubble wrap and squashed shell closed.
Build is temporary, dependent on eventual disposition, sell or keep. Could fit 20Ah++ in shell.
Battery meter (6 LED) might work well with saggy SLA but still reads full when Lithium is near 36V, fortunately, Samsung cells are empty near a static 3.4V, so there is some indication. Might replace meter with a "proper" LCD volt meter?

Watseka XP rebuild thread
Update -
Ran batteries down to 1, of 4, green LED (full throttle cruising on level)
Which instantly recovered to 3, of 4, green LED (throttle released)
Battery metered at 35.8V and all 60 cells metered at precisely 3.58V (except last pair = 3.59V)
This is a testament to quality Samsung cells and/or a quality BMS!
(Stats corrected - hadn't had my coffee yet)
#1 metered a 3.093mAh recharge to 42.0V
#2 metered a 3.095mAh recharge to 42.0V
#3 metered a 3.126mAh recharge to 42.0V

3.58V, based on Samsung ICR18650-22p's minimal discharge graph, shows plenty of capacity left, ~20%, indicating these packs seem still near 85% of rated capacity, and better than 90% of tested new at 3.40V.

Image

The 3 packs of this build were tasked with powering my Snow Beast through this last Winter, which involved cruising at 20mph through cold and snow and slush ... 36V 28A controller, so 3C startup and tough conditions, 2c cruising in adverse conditions and 1C cruising in ideal conditions = dozens and dozens and dozens of cycles in harsh conditions.

Re: Homemade Battery Packs

Posted: Jul 15 2019 5:44pm
by DrkAngel
Battery, and bike, doing nicely.
3 20A continuous BMS is overkill on a 36V 250w motor. Don't think 1 is ever tasked to continuous capability ...

Image

... so, think I'll use 1 hoverboard pack and shoehorn in another 10s 6 or 8p and tack onto the hoverboard battery's external BMS's series contact points. Will have to do some sorting and creative positioning to get maximum capability.

Watseka XP
Image

Ordered up missing, broken and worn out parts, not the basket tho ...

Re: Homemade Battery Packs

Posted: Jul 15 2019 9:21pm
by thundercamel
Interesting kickstand; must flip backwards I'm guessing.

Re: Homemade Battery Packs

Posted: Jul 16 2019 3:30am
by DrkAngel
thundercamel wrote:
Jul 15 2019 9:21pm
Interesting kickstand; must flip backwards I'm guessing.
Spring loaded, flips backward. Also has a heavy lock in kickstand position.
Can be used as exercise bike?
Add 3 phase bridge rectifier for use as a generator?
Oops ... forgot this was a geared hub motor- freewheels = not generator capable.

3 phase BR.jpg
3 phase BR.jpg (114.05 KiB) Viewed 758 times

Re: Homemade Battery Packs

Posted: Jul 31 2019 2:13pm
by DrkAngel
Triple Hoverboard Pack

Got lazy and fit 3 x 10s2p 36V 4.4Ah into an e-Zip battery case as upgrade on my old Comfort Cruiser.

Image

Neighbor who bought the bike from me with 25.9V battery moved up a hill.
Same as my Snow Beast, he is now geared down and volted up for near 700w motor output at 20mph.
He lost Ah and total capacity but gained torque needed for his hill and the BMS functions of the hoverboard batteries!

36V 13.2Ah = 475Wh Li-ion
down from
25.2V x 26.4Ah = 665Wh Li-ion
but replacing oem
24V 10Ah = 240Wh SLA = 120Wh usable

Re: Homemade Battery Packs

Posted: Aug 27 2019 9:10am
by DrkAngel
Cleaning up my "old" inventory of Dell laptop Lipo. Building a bulk 3s "12V" pack to power greenhouse water pumps, lights, radio etc. Just tacking together all the lesser 3s2p "bricks" that retained equal voltage per bank = no self discharge.

Image

Will use 100+ "12V" 4.32Ah "bricks" for a feasible 300+Ah = 3.6kWh
Should be sufficient for running LED lighting 2 hours per day) and mini, low pressure submersible water pumps (1 hour twice weekly) and radio. for a week.

Have small solar panel, but will get larger or manually charge weekly(?).
Will soon need extra hours of light to keep plants flowering.
Yes, I made up 12V grow-flower "full-spectrum" LED modules.

Re: Homemade Battery Packs

Posted: Sep 01 2019 5:20am
by Jaz1751
Hello,

Doing a massive ebike build, having difficulty sourcing a 48v 40plus Ah BMS (13s 13p)

Any recommendations would be great!

Thanks

Re: Homemade Battery Packs

Posted: Sep 01 2019 10:00am
by DrkAngel
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...
13s BMS's, many 40A and higher.
40Ah battery is not so much a factor, as expected Amp draw. Controller Amp rating is a more accurate indicator of needed BMS.

Sorry - forgot to add link to "13s BMS" ... fixed now.

Added 14s link also.

14s BMS

14s, vs 13s is often the difference of reaching 30mph, or not quite ...

Re: Homemade Battery Packs

Posted: Sep 01 2019 10:31am
by thundercamel
You may also prefer 14s, to use more of the available energy before you hit the low voltage cutoff in the controller.