Homemade Battery Packs

Batteries, Chargers, and Battery Management Systems.
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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Jun 28, 2017 6:06 am

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Now that the ...
Floureon 7S 5000mah 25.9V 40C Lipo Battery <$60 delivered from USA are all sold ...

"Recommended for rebuild of eZip 24V RMB battery packs.
Will fit up to 4 x 5Ah = 25.9V 20Ah vs oem 24V 10Ah (5-6Ah usable) SLA.
Every 24V controller I've ever tested works properly with 7s 25.9V battery, but a bit faster with some more torque ...

Image

eZip RMB pack internal dimensions:
150mm x 65mm x 230mm"

... I am forced to ration my 5 brick inventory.
2x = 25.9V 10Ah testbed looking good, but will likely add BMS and sell with a refurbished eZip. 20-30A $10 BMS - is perfect for 1 eBike with 20A controller..

Picked up a couple hundred Samsung 2200mAh 10-20A 18650 cells ... and now the LiPo look much less attractive for pairing with higher capacity Laptop cells.
.
Last edited by DrkAngel on Sep 04, 2017 10:55 am, edited 1 time in total.
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Re: Homemade Battery Packs

Post by DrInnovation » Jun 29, 2017 12:56 pm

Just build a home made pack from recycled cells from some military batteries I had laying around. A mix of two types, I tried to balance the capacities in my strings while also trying to keep the original pre welded groups for stability. Then I soldered 12gauge wire connecting them. I got 10s8p so about 19Ah @36v which fits nicely in the battery box that used to hold 2 12ah12v SLA batteries. Tight fit in one dimension and enough room above them to put the BMS. I built it as 2 groups ov 5s8p, which basically replace 1 SLA each. In building I used tie-wraps to keep the pack tight as I did the soldering. Grinding the nickel tabs and tinning each before I added the connecting 12-gauge wire. Plenty of cross connects in the serial direction. After soldering each brick is very stable.

I started the build after buying a used amped bike kit (36v front hub). It included a bottle battery with BMS. Unfortunately, absolutely none of the 40 batteries from that system were usable. All would charge to 4.2 a dozen or so would stay stable at 4.1X few days while other self-discharged to 3.8 or so with 2-d days. (and after 3 weeks some discharged to 2.3). None had a capacity of mote than 500mah despite being pansonics rated at 2.5ah (the green ones in the photos below). Given the system had a BMS I was puzzled as to why none were working and did lots of reading here. I gave up on them and built the pack without them. Eventually I found out why, the kit I bought (which the owner said only lasted a few weeks before the battery would not longer work), was supplied with a 44v lifepo charger not at 42v lion charger. I had initially hand-=charged all the cells before the build, did some testing then pugged it in to the charger to test the BMS. Luckily Id did not leave it alone too long, as after 30min the batteries were at 4.3v.. and the BMS was super hot. Of course I should have check things, but somehow expected the "kit" had the right charger. Learned once again to Check Check Check. And its a clear lesson that BMSs are not a bullet proof solution.. could have easily caused problem (on my pack or the original) if left plugged in for days.

In the end I leaned a lot from this (and other) threads. Thanks for all the advice/experience of the group. A few pics below.. I'm still learning, so would appreciate any feedback on the build.

Not shown in picks, but I wired the BMS so that it is for charge only (it was only 10A and I wanted to be able to use more current while riding. I can monitor imbalance by hand and expect I'll not get near LVC anyhow and will be setting up for a celllog8.
One last question.. any advice on setting up so I can have a Celllog monitor 10s? I was thinking I could do 2 connectors and check both, but from an alarm view I wondered if it could handle skipping cells (so monitor 2 at a time) and then just leave it hooked up?
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Owner of a Crystalyte 4012/409 with 10aH 16s Headway on a old huffy frame. Its not fast but it climbs my daily commute up 8% and 10% grades nicely. Previous bike (and soon to be selling) a 24v Lashout 600w with RCLipos. My bigger "E-ride" is a chevy volt.

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Re: Homemade Battery Packs

Post by DrkAngel » Jul 02, 2017 11:58 am

Tips on soldering onto cells:
Fold and solder to excess tab

My preferred method.
Least chance of heat damage with good solid contact!

pre"tin" tab:
flux, solder small bead of solder to tab
flux and pre-solder wire at connection point
re-flux
place wire against battery solder point
use probe (small chromed screwdriver?) to hold together
heat wire only until solder collapses together
continue to hold solder connection steady until fully set.

I prefer to use tinned copper braid.
Seems more durable ... holds up to flex and abuse better

Wrapping battery build tightly with clear boxing tape stabilizes cells and minimizes flex and cell sheathing wear.
Allows visual inspection and multimeter probes easily poke through for diagnosis-testing
Last edited by DrkAngel on Jul 07, 2017 4:22 am, edited 3 times in total.
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Re: Homemade Battery Packs

Post by markz » Jul 02, 2017 12:44 pm

Ah DrkAngel packing tape, great I would never have thought of that. Braid is good too, what guage is good? Probably would soak up a ton of solder though.

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Re: Homemade Battery Packs

Post by DrkAngel » Jul 04, 2017 7:31 am

DrkAngel wrote:Mower upgrade
Upgraded my 24V 20Ah SLA mower last year.
Been running with upgraded 22.2V 34.56Ah (6s16p) Old used Laptop Lipo at probably 25Ah++.

So, pushed over the main brick and was able to squeeze in another 1s16p.
Previous 6s were matched in capacity and IR, added bank was just insured to be of better!
Lesser would drag down whole pack - better allows full use, with power to spare.

Image

Yeah, oops ...
6s battery had no fuse installed.
Had to rewire, so dropped in a 40A fuse + holder.
Too wet to try and weather won't dry up for a few days but I expect performance to be noticeably improved!
Made my 1st run with 7s16p recycled Laptop LiPo.
Mowed store's yard, neighbors yard, small community park and 2nd small community park.
Blade speed and torque are noticeably improved!
Original bank's discharged voltages ranged from 3.731V to 3.728V and add in bank @ 3.78V, so looks excellent!
Cell temperature, after mowing both parks, was < 100ºF on 80ºF day.
iMax "bulk" charge from 3.73 to 4.17V = 26.97Ah
4.176 - 4.182V bulk charge resultant voltage.
3.7V (safe empty) to 4.10V (Optimal) looks to be 25Ah+ usable, with generous safety margins!
24V SLA leds showed 75%, with motor idling over sidewalk, when cells near 3.75V (7s=26.25V )

Very happy and is liable to last "my" lifetime ... might want to get a spare Homelite mower?
Last edited by DrkAngel on Jul 08, 2017 8:34 pm, edited 2 times in total.
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Re: Homemade Battery Packs

Post by DrkAngel » Jul 04, 2017 9:29 am

Sony Laptop LiPo mower battery
7s16p 2160mAh cells
25.9V 34.56Ah

These SONY lipo cells were previously capacity mapped
So I was able to compare tested vs proposed vs actual capacity


Image

Charged 3.73V to 4.17V = 27Ah
Proposed 3.70V - 4.10V = 28Ah
Full capacity 3.68V - 4.20V = 31.4Ah ( 91% of new rated - without tapping the energy below 3.68V! from 8-10 year old cells!!! )

.
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Last edited by DrkAngel on Oct 17, 2017 8:26 am, edited 1 time in total.
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Re: Homemade Battery Packs

Post by markz » Jul 08, 2017 1:10 pm

I am making another 12Ah pack from Makita's, shall have a total of 18Ah + 12Ah = 30Ah all in the frame.
I find when I go full throttle for some time, my total distance is reduced by 1/3 but even with 18Ah I can get 30km at cruising speeds with one good hill. I want to have a setup where this pack I am currently building would be my all the time, in the city, cruiser pack. Should get 50km total, no guerrilla charging. Last night I did a schools parking lot block heater outlet. However I want the ability to also go out into the country. So all I have right now is the ability to go 100km between charges. Another box of Makita's shall get me 200km, placed in the inline trailer. 100km = 60Ah but 200km = 120Ah, so I need to think about how am I going to charge that. I came to the conclusion that with my two Meanwells in series getting 41.5V (10S) and 16Ah on my 36V pack, and taking 6A from the wall. I can actually get 32Ah into the pack, pulling 12A from a single outlet. Even at that its 2 hours per 100km 60Ah pack. Which aint too bad actually. To get more Ah into the pack will require expensive gear. I do like the Meanwells.

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Vetting Floureon (7s 25.9V 5000mAh)

Post by DrkAngel » Jul 09, 2017 2:24 pm

Copy of post from alternate thread.
My 1st "vetting" of high output (40C) LiPo.
Testing is to determine-evaluate cell durability-reliability at less drastic discharge rates!
2 x 7s 5000mAh (25.9V 10Ah) as test module.
24V 28Ah controller though eZip 450w motor
2.8C - 1C discharge rate

see - Vetting Floureon 40C (7s 25.9V 5000mAh )
"Built a 150A meter with XT60 connectors.
(All my 100A have T Plug)

Image

Yes, 4 Bricks 20Ah fit snugly in eZip RMB pack.

Image

With plenty of room for BMS, cooling etc, 10Ah fits nicely.
True 10Ah < 5lb pack compared to 5-6Ah usable >16lb SLA oem pack.

Image

And ... just found the best feature on one of my already favorite "tools".
Looking through the manual ... finally ... I found an unadvertised Low Voltage Alarm function!

Set to 3.500V then turned AL to "on".

Image

Need to build more Ethernet cable adapters for all my bikes. (8 wires in nice bundle, readily available with large color and quality selection.)
LCD is perfect for daytime!
May add polarized filter ...
Will definitely keep ziplock bag handy for in ... weather.
Might need to shade due to sun-heat "blackage"?"
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: Homemade Battery Packs

Post by markz » Jul 09, 2017 4:44 pm

LiPo's are a good alternative, but you have to know exactly what you are doing.
I would do LiPo again, MultiStar's for sure.

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Samsung ICR18650-22P

Post by DrkAngel » Sep 06, 2017 4:06 pm

Picked up a decent quantity of Samsung ICR18650-22P cells. (near 600, "new")
In 10s2p bricks w/BMS - 36V 4.4Ah
Graph shows "effectively empty" at 3.40V - (static condition)

Cells are rated at:
10A max sustained output
20A surge output

Much better than the LiPo and 18650's I've pulled out of laptops.

At 2p, that's 20A continuous and 40a surge, they look perfect for rebuilding NiCd power tool packs!
Tested for fit in:
12V 1.2Ah NiCd >> 3s2p 11.2V 4.4Ah B&D Firestorm battery packs 2 built
14.4V 1.2Ah NiCd >> 4s2p 14.8V 4.4Ah B&D Firestorm battery packs
18V 1.4Ah NiCd >> 5s2p 18.5V 4.4Ah B&D Firestorm battery packs 2 built
24V 1.4Ah NiCd >> 6-7s2p 22.2-25.9V (need to test fit and function of 7s) 4.4Ah B&D Firestorm battery packs
18.5V 3-4Ah Li-ion >> 18.5V 5s2p 4.4Ah Ryobi Lithium

Will test, build and document ...
... check for various other possible brands-voltage upgrades also.

Yes, will build 7s and 10s8p (36V 17.6Ah) eBike battery packs using these cells.
10s 36V for use with front hub and various of multi-voltage capable eZips.
7s for eZips etc.
Last edited by DrkAngel on Sep 06, 2017 7:31 pm, edited 1 time in total.
A little learning is a dangerous thing;
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There, shallow draughts intoxicate the brain,
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I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: B&D Firestorm Battery Packs - Lithiumized!

Post by DrkAngel » Sep 06, 2017 5:23 pm

Broke open 2 - 10s2p bricks and:
2 x 18V(5s2p) Firestorm = 20 cells
and
2 x 12V(3s2p) + 1 x 14.4V(4s2p) = 20 cells
for Lithiumization.

5s2p went nicely into 18V packs
ss5s_01.jpg
ss5s_01.jpg (186.52 KiB) Viewed 1103 times
Note: I arraigned cells so that the metal negative strip is positioned directly over the negative casing of the negative cell.
A lucky happenstance ... perhaps.

3s2p went nicely into 12V packs
ss3s_01.jpg
ss3s_01.jpg (135.48 KiB) Viewed 1103 times
Planned! was this circuitous series route that similarly placed the negative cell casing under the metal negative tab.

2 x 18V and 2 x 12V completed.
14.4V (8s2p) will take a bit more planning, either a bit of reforming or some iffy case trimming.

Oh ... found 1 single roll of fabulous duct tape, using as sparingly as possible. No known source for replenishment. ... ?
Update - VentureTape 1515 extra thick-sticky available ... but not cheap
Last edited by DrkAngel on Sep 09, 2017 11:02 am, edited 2 times in total.
A little learning is a dangerous thing;
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I enjoy enlightening ... and enlivening the spirit of the innovators.

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Samsung ICR18650-22P - Balance leads

Post by DrkAngel » Sep 07, 2017 12:31 pm

Battery Lithium upgrades not installed with balance leads ... yet.
Just found a budget source for 10 x 22AWG silicone balance leads.

Waiting for good balance leads before installing.
Cells are new and from same packs that were delivered with good equal voltage, so I have reasonable confidence in quality ... but will make initial discharges in stages and check cells for equality ... till near 3.40V.
Samsung ICR18650-22P - 3.40V seems optimal as deepest static discharged voltage.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: Homemade Battery Packs

Post by DrkAngel » Sep 10, 2017 2:24 pm

14.4V (8s2p) will take a bit more planning, either a bit of reforming or some iffy case trimming.
I have to credit my 2nd cousin(?) ... cousin's son, with a "solution" for:
B&D 14.4V lithiumization.

Involved cannibalizing an 18V pack, fortunately I have spares, to create an 18.5V 4400mAh pack for my 14.4V tools.
This does increase tool speed and torque an additional 28% ...
and capacity (18.5V x 4400mAh = 81.4Wh) ÷ (14.4V x 1200mAh = 17.28Wh) to 471%.

Black and Decker 14.4V Firestorm tools was my 1st cordless power tool set.
Higher voltage will be perfect for my:
VSR drills
Reciprocating saw Variable Speed (higher voltage less damaging than "bogging down" damage?
5⅜" circular saw - seemed anemic at 14.4V
Questionable will be:
Light - will need to get higher voltage bulb or convert to ≤ 21V LED

By creating a Hybrid 14.4-18V pack, 4s2p or even 5s2p will fit comfortably.
Just used the bottom of an 18V and cut a 14.4V top and finished with the partial top of the 18V.
Image
Add on top allows easy, 2 screw, access for balance.
4s2p 14.8V Lithium at present, just a prototype ... 5s2p fits nicely!

Image

Another advantage is the larger, more stable base for standing tools.

Image

No 14.4V tool seems to be interfered with by longer base . ... ?
A little learning is a dangerous thing;
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There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: Homemade Battery Packs

Post by GlowInTheDarkNinja » Sep 28, 2017 2:05 pm

Hey all,
I have 140 18650 cells that I plan to configure in to a 20s7p battery. Since I'm using 7p, I'm thinking about using 2" - 2.5" ABS, or Polycarbonate tube to house my batterys. Depending on how snug the fit is at 2", I was thinking about wrapping the batteries, or lining the tube with either Neoprene, or Poron.
Poron and Polycarbonate look to be better materials but are also more expensive. I want my batteries to make contact with copper bus plates through compression on either end of the tube, so it should be easy to service in the future. With how many cells I have and the oddish shape of my frame, I'm thinking I can make 4x tubes with 4 parellel packs in each, wired in series. Then the remaining 4 packs will be able to fit in a housing made in my small triangle.

Has anyone used tubing as their housing? Does it work as well as I imagine? Is Poron or Ploycarbonate good enough to justify about double the cost? Also, what are some solutions for mounting, I have a large, 2.0+" round tube, and a 1.5"x2" eliptical tube that will be challenging to mount to. The frame is also aluminum.

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Re: Vetting Floureon (7s 25.9V 5000mAh)

Post by timmy66 » Sep 30, 2017 11:31 am

DrkAngel wrote:Copy of post from alternate thread.
My 1st "vetting" of high output (40C) LiPo.
Will definitely keep ziplock bag handy for in ... weather.
Might need to shade due to sun-heat "blackage"?"
Dear DrkAngle :

Have you had good experience with the accuracy of both that current meter you're showing, and the "Smart Battery Meter" that you have ? i have tried some of the $1.25 1s-18s RC alarm buzzers, and they do not work well at all. Thank you.

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Re: Homemade Battery Packs

Post by DrkAngel » Sep 30, 2017 4:36 pm

Smart battery meter seems "reasonably" accurate, but I compare to my Fluke multimeter regularly.
The 1-8s alarm meters vary greatly, some maintain reasonable accuracy, while others "drift" in accuracy.
Newest couple w/black housing seem OK, at present.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: Homemade Battery Packs

Post by Hillhater » Oct 01, 2017 7:20 pm

GlowInTheDarkNinja wrote:Hey all,
I have 140 18650 cells that I plan to configure in to a 20s7p battery. Since I'm using 7p, I'm thinking about using 2" - 2.5" ABS, or Polycarbonate tube to house my batterys. Depending on how snug the fit is at 2", I was thinking about wrapping the batteries, or lining the tube with either Neoprene, or Poron.
Poron and Polycarbonate look to be better materials but are also more expensive. I want my batteries to make contact with copper bus plates through compression on either end of the tube, so it should be easy to service in the future. With how many cells I have and the oddish shape of my frame, I'm thinking I can make 4x tubes with 4 parellel packs in each, wired in series. Then the remaining 4 packs will be able to fit in a housing made in my small triangle.

Has anyone used tubing as their housing? Does it work as well as I imagine? Is Poron or Ploycarbonate good enough to justify about double the cost? Also, what are some solutions for mounting, I have a large, 2.0+" round tube, and a 1.5"x2" eliptical tube that will be challenging to mount to. The frame is also aluminum.
Use the search function.
There are many such tube based pack builds of various designs.
This is one such..
https://endless-sphere.com/forums/viewt ... k#p1052025
This forum owes its existence to Justin of ebikes.ca

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Re: Homemade Battery Packs

Post by GlowInTheDarkNinja » Oct 03, 2017 3:42 am

Hillhater wrote:
GlowInTheDarkNinja wrote:Hey all,
I have 140 18650 cells that I plan to configure in to a 20s7p battery. Since I'm using 7p, I'm thinking about using 2" - 2.5" ABS, or Polycarbonate tube to house my batterys. Depending on how snug the fit is at 2", I was thinking about wrapping the batteries, or lining the tube with either Neoprene, or Poron.
Poron and Polycarbonate look to be better materials but are also more expensive. I want my batteries to make contact with copper bus plates through compression on either end of the tube, so it should be easy to service in the future. With how many cells I have and the oddish shape of my frame, I'm thinking I can make 4x tubes with 4 parellel packs in each, wired in series. Then the remaining 4 packs will be able to fit in a housing made in my small triangle.

Has anyone used tubing as their housing? Does it work as well as I imagine? Is Poron or Ploycarbonate good enough to justify about double the cost? Also, what are some solutions for mounting, I have a large, 2.0+" round tube, and a 1.5"x2" eliptical tube that will be challenging to mount to. The frame is also aluminum.
Use the search function.
There are many such tube based pack builds of various designs.
This is one such..
https://endless-sphere.com/forums/viewt ... k#p1052025
Thanks for the link. I wish I could see the images. I'll see the search bar for more.
I was also wondering if cells towards the pos or neg of a back tend to lose there voltage faster. I thought I saw something about it before. To the search bar I go!

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Re: Homemade Battery Packs

Post by dequinox » Oct 07, 2017 8:31 pm

Anyone have an opinion on these from eBay?

Even if they exhibit half the advertised capacity they could be worth the $ in my opinion. That's half a kWhr for $70.
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Re: Homemade Battery Packs

Post by DrkAngel » Oct 07, 2017 8:40 pm

Similar unbranded, ultrafire also, prove out closer to 300mAh than to 3000mAh
A little learning is a dangerous thing;
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There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: Homemade Battery Packs

Post by dequinox » Oct 07, 2017 9:23 pm

I do know to stay away from ultra fire... those are akin to button cells.

I might try a small qty of these and test their capacity. I'm still working thru my used 18650 backlog, but thought I'd like to find a good source for new cells soon.
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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Oct 09, 2017 12:20 pm

Genuine Samsung 2200mAh cells $1.10 -$1.25 each
May be all sold?

Same seller with LG and Sona cells!

LG 2200mAh of poor to fair C rate but good reputation

Sona(?) 2000mAh of excellent C rate but unknown reputation

Samsung 2200mAh of good C rate and excellent reputation
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Spongeworthy
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Re: Homemade Battery Packs

Post by Spongeworthy » Oct 13, 2017 6:33 am

I see alot of builds that run the + and - leads along all the cells in the first and last groups, what are the benefits to this? I'm building a triangle pack so this isn't an option for me due to the weird cell arrangements.

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Oct 13, 2017 6:54 am

Spongeworthy wrote:I see alot of builds that run the + and - leads along all the cells in the first and last groups, what are the benefits to this? I'm building a triangle pack so this isn't an option for me due to the weird cell arrangements.
All the + series end cells and - series end cells must be connected!
Ideally with a reasonably heavy (large gauge) "rail" to provide good equal discharge from each series of cells.

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A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

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Endless Sphere Wiki

Spongeworthy
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Re: Homemade Battery Packs

Post by Spongeworthy » Oct 13, 2017 2:50 pm

DrkAngel wrote: All the + series end cells and - series end cells must be connected!
That pretty much goes without saying.
DrkAngel wrote: Ideally with a reasonably heavy (large gauge) "rail" to provide good equal discharge from each series of cells.
Why is it more important for the ends of the pack to have more conductive mass than say in between each parallel group? Doesn't the same amount of current run through both? I'm just a bit confused since I see some packs that don't do this at all and just solder leads directly onto the + and - ends of the pack, and other packs with thick copper bus bars at the end.

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