Homemade Battery Packs

Batteries, Chargers, and Battery Management Systems.
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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Sep 02 2019 7:49am

DrkAngel wrote:
Sep 01 2019 10:00am
.
...
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 ...
Though, with my multitude of 3s2p LiPo, a 15s BMS might be my choice for for a "48V" battery.

48V 750w hub motor ...

Series .... Nominal V ... Charged V ...
12s .......... 43.2V .......... 50.4V = 720w motor output
13s .......... 46.8V .......... 54.6V = 775w motor output
14s .......... 50.4 ........... 58.8V = 840w motor output
15s .......... 54V ............. 63V = 900w motor output - confirm > 63V caps? (61.5V = charged to, lifesaving, 4.10V per cell)
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Re: Homemade Battery Packs

Post by Hillhater » Sep 02 2019 6:21pm

DA... sorry to drift a little OT..but, ref Capacity Mapping,...
.....have you ever done a “capacity Map” for the Boston Power 5300 cell ?
viewtopic.php?f=14&t=90938
I checked but could not find one in your extensive index .
Thanks ..HH
This forum owes its existence to Justin of ebikes.ca

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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Sep 04 2019 7:41am

Hillhater wrote:
Sep 02 2019 6:21pm
DA... sorry to drift a little OT..but, ref Capacity Mapping,...
.....have you ever done a “capacity Map” for the Boston Power 5300 cell ?
viewtopic.php?f=14&t=90938
I checked but could not find one in your extensive index .
Thanks ..HH
Did a quick Capacity map in "Capcity Mapping thread", see - Boston Power Swing 5300
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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transposon   100 W

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Re: Homemade Battery Packs

Post by transposon » Nov 06 2019 10:37am

DrkAngel,

Do you still recommend using tinned copper braid? I assume you use the flat braid. Do you use it for both the series and parallel connections? What about stranded copper wire? Also, I am having trouble seeing the braids rated by gauge on Ebay. I am just seeing the width listed. E.G. 1/4", 1/2" etc. What width do you recommend? I only plan on pulling around 25A max.


Also, do you recommend using an extra cell or two in series to cope with the increased voltage sag seen in these laptop pulls?


Thanks a lot. I am glad someone is putting work into making all of this information easily available. This helps batteries go on bikes and not in landfills.

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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 07 2019 7:10pm

I cleaned out someones inventory of odd length pieces, don't remember the size. Pulled long and squashed flat it is about 5/16" wide. Works good for me, guessing about 8ga?

However, been using a lighter gauge in my power tool upgrades and have had 2 packs fail do to degraded-broken TCB. Just not heavy or tinned sufficiently for the amps. I guess.
Stranded copper is subject to the same deterioration if too light or exposed, thin stranded particularly.
Just a point ... Tinned Copper Braid is stranded copper, "tinned" with a protective coating.
Last edited by DrkAngel on Nov 07 2019 8:13pm, edited 1 time in total.
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methods   10 GW

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Re: Homemade Battery Packs

Post by methods » Nov 07 2019 7:21pm

Wow - nice Links pack!

-methods

DrkAngel wrote:
Mar 27 2011 10:20am
Index - April 2019 Updating

Tools and Parts

..........................................

#2. New RC Lipo 10 - 11.1v 5700mah packs.
20C surge 15C sustainable.
30 3.7v 5.7ah cells
Total cost ? About $200.
48v 11.4ah pack.
37v 17.1ah pack
25.9v 22.8ah pack
Charger and PCB - about $100 - $120, can use my Li-ion components.

#3 LiFe from recycled battery packs.
80 - 3.2v 5ah cells,.
Cost? about $160.
25.6v 50ah pack
38.4v 30ah pack
48v 25ah pack
Charger and BMS not priced yet, but should be near $150.

All cells acquired, am presently charging-testing individual Lipo cells.
Will do preliminary tests with a 22.2V, (25.2v at full charge), 21.6ah pack, on a 24v bike, (batteries are arranged in 3 cell, (11.1v), "bricks").

After individual charging, bricks will be precisely discharged, any voltage variance between cells, should pinpoint anything, weak, damaged, or substandard, and will be eliminated before "pack" assembly.



Will post pictures and progress reports
Increasing battery voltage and controller current limit will result in a non linear experience

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 15 2019 6:48am

Just got a case of new Samsung ICR18650-26F 120 @ $1 each (plus shipping) from US

Image

Sold out - but have restocked several times!

Cells are rated at 2C max discharge, which is great for most of my builds. Typical are near 1C max and <0.5C sustained.
Problem is I have so many optimal uses and only 120 cells ...
25.9V 31.2Ah for eZips (84 cells)
33.3V 31.2Ah for Turbo eZips (108 cells)
Watseka XP 37V 4.4Ah Samsung 22p hoverboard battery paralleled, through BMS with 60 cells for 37V 20Ah 250w geared hub for .5C max
3s1p BMSed for 12V Lanterns etc?
A little learning is a dangerous thing;
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There, shallow draughts intoxicate the brain,
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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 17 2019 5:49am

DrkAngel wrote:
Nov 15 2019 6:48am
Just got a case of new Samsung ICR18650-26F 120 @ $1 each (plus shipping) from US
Nice items, with identical voltage. Modules seem not "powered", might require some circuit to additional contacts to "power on" the battery. Shame, have use for some batteries with protection circuit.
Will try to keep in 3s construction for convenience, but tormenting myself over best or most needed application. I need more! Might have to get more before I can decide and get started on their 1st project.
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 » Nov 29 2019 11:39pm

Bargain! Cells or 36V 5.1Ah bricks x 10 @ $24.99 each.
36V 5.1Ah

Limited time super bargains for this weekend!
Last edited by DrkAngel on Nov 30 2019 1:50am, edited 2 times in total.
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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john61ct   10 GW

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Re: Homemade Battery Packs

Post by john61ct » Nov 30 2019 12:41am

Samsung INR18650-29E

so you're de-rating to 2550mAh each at 2P to get 5.1Ah?

36V means 10S, so each pack 10 cells?

Or do you mean must buy 10 packs to get that price?

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 30 2019 1:50am

DrkAngel wrote:
Nov 29 2019 11:39pm
Bargain! Cells or 36V 5.1Ah bricks x 10 @ $24.99 each.
36V 5.1Ah

Limited time super bargains for this weekend!
fixed the link to 36V 5.1Ah batteries !
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 john61ct » Nov 30 2019 2:48am

Thanks, clearer now. Can they be wired in series for usage at 72V 20S

charge with 2x 41V chargers at the midpoint tap long as isolated

as is, leaving their BMS in place?

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 30 2019 3:01am

john61ct wrote:
Nov 30 2019 2:48am
Thanks, clearer now. Can they be wired in series for usage at 72V 20S

charge with 2x 41V chargers at the midpoint tap long as isolated

as is, leaving their BMS in place?
Sounds feasible.
I ordered up a dozen for various projects and spares. Plus some of the 200A Li-ion, Ryobi packs, 9s fireproof, AAA's, and power banks.
Pondered for quite a while before I ordered 31 - 8Ah 200A Li-ion.
2 - 7s2p 25.9V 16Ah eZip batteries + 3s1p 12.6V (charged) 8Ah 12V car starter or light system PS
or
1 - 14s2p 51.8V 16Ah + 3s1p 12.6V (charged) 8Ah 12V car starter or light system PS
or
1 - 10s3p 37V 24Ah + 1 spare
or
1 - 10s2p 37V 16Ah + 1 - 10s1p 37V 8Ah + 1 spare
Last edited by DrkAngel on Nov 30 2019 4:00pm, edited 1 time in total.
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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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 30 2019 3:29am

DrkAngel wrote:
Nov 29 2019 11:39pm
Bargain! Cells or 36V 5.1Ah bricks x 10 @ $24.99 each.
36V 5.1Ah

Limited time super bargains for this weekend!
Specs on the cells in the $25 36V 5.1A battery bricks - EVE icr18650/26V
Interesting is the 4.2V vs 4.1V deterioration chart.
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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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Nov 30 2019 9:38am

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%.
Well, starting at 42V and ending at 33V invokes a drastic and noticeable performance drop.
Got to thinking, since I just got a bunch of batteries and like to build oversize packs anyways ...

... why not tack on an extra "s" in series to the end of these BMSed packs ?
3.7V x 11 = 40.7V
3.5V x 11s = 38.5
Now 40.7V - 38.5V is a performance variance I can live with! (probably charge to 41V (3.71V per cell) or even OEM charge to 42V (3.82V per cell))
Will need to monitor empty voltage, but 10s BMS will cut power near 33-34.1V.

And, of course, I can always charge up to 45.1V (11s @ still life doubling 4.10V) for any trippin'.
ICR18650-26V.jpg
ICR18650-26V.jpg (65.4 KiB) Viewed 3545 times
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.
36V 5.1Ah.jpg
36V 5.1Ah.jpg (62.5 KiB) Viewed 3492 times
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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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Dec 07 2019 6:36am

.
...
abbondanza

Receiving a wealth of battery potential!
Battery Hookup (alarmhookup on ebay) had-has a great discount on some recycled batteries.
36V 5.1Ah BMSed batteries, as low as $24.99 each (for 10x quantity) - got 12
8Ah LiPo cells 25-50C discharge and 15C charge $4 each - got 31
Ryobi 40max 3Ah for $6 - parts or repair - got 12
Ryobi 18V 1.5Ah batteries - parts or repair - $1.50 - got 20
9s2.89Ah LiPo modules in fireproof shell @ $4.99 - got 6

Much more available and sale still going on (12/7)
https://batteryhookup.com/ overwhelmed with sales - expect delivery delays!
No, I am not affiliated, just spreading the good cheer ...
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 Tony01 » Dec 07 2019 6:28pm

Spim08hp cells from alarmhookup on eBay. 21s3p. Custom battery bars made from 6101 aluminum. Build was run in the summer now finishing it up.

Pics too big to upload, here’s build thread on gas mb site.
https://motorbicycling.com/threads/worl ... ost-679798

Cost me $500ish total plus about 12hrs labor.
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Re: Homemade Battery Packs

Post by DrkAngel » Dec 07 2019 10:49pm

Finally received shipment notifications on all items ...
Plenty of projects to help keep me busy through the long cold Winter.
DrkAngel wrote:
Dec 07 2019 6:36am
.
...
abbondanza

Receiving a wealth of battery potential!
Battery Hookup (alarmhookup on ebay) had-has a great discount on some recycled batteries.
36V 5.1Ah BMSed batteries, as low as $24.99 each (for 10x quantity) - got 12
Have 5 36V compatible eBikes
8Ah LiPo cells 25-50C discharge and 15C charge $4 each - got 31
48V 1000w hub kit needs POWER! 14s2p with 3 spares or 15s2p with 1 spare?
Ryobi 40max 3Ah for $6 - parts or repair - got 12
Need something to play with, try to resurrect packs ... then buy Ryobi 40V tools? or parallel for 36V eBikes? or my 36V SLA mower?
Ryobi 18V 1.5Ah batteries - parts or repair - $1.50 - got 20
Got lots of Ryobi 18V tools, resurrect or scavenge cells to rebuild some packs?
9s2.89Ah LiPo modules in fireproof shell @ $4.99 - got 6
Will reassemble as 3s3p for "12V" 8.67Ah modules

Much more available and sale still going on (12/7)
https://batteryhookup.com/ overwhelmed with sales - expect delivery delays!
No, I am not affiliated, just spreading the good cheer ...
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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DrkAngel   100 GW

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Re: Homemade Battery Packs

Post by DrkAngel » Dec 08 2019 12:32pm

Copied from Optimal Charge Voltage thread -
DrkAngel wrote:
Nov 30 2019 9:10am
EVE ICR18650/26V looks to have greatest energy density between 15% and 60% (approximately from 3.5V to 3.7V)
I will likely parallel enough 36V batteries to limit controller draw to <1C and limit charge dependent on anticipated need.
1 advantage is the ability to "timer" charge at full Amps, dependent on battery voltage to obtain fastest charge, without the annoying trickle charge incumbent with CC\CV charges.
Set 36V .5C "charger" to 41V but limit with timer to add the required number of Ah.
As a "reserve", there is substantial energy density down to 33V.

Image
Older LiCo cells were near empty at 3.6-3.7V, this provided a reasonably narrow power band of 42V-37V full to empty for a 12% differential.
Newer LiCo like the Samsung ICR18650-22p "emptied" near 3.4V for a ~20% differential.
Even worse, the EVE ICR18650-26V cells I just ordered near "empty" at 3.3V for a ~22% differential.
This "differential" is the difference between performance from a full battery and a near empty battery.

As displayed a 42-33V differential has a drastic speed-torque-power variance.

Image
Then I noticed a very dense region of energy in these EVE cells. A very large percentage resided between about 3.5V and 3.7V, more than from 3.7V to 4.2V.

Image

How best to take advantage ... ?
Well 37V to 35V is a nice tight differential ~`5.4%. But 37V is fairly pitiful on an eBike used to 42V!
So, decided to build a battery and add 1s to the 10s BMSed battery packs.
Current plan is for 4x 10s2p +1s10p for an effective 11s8p, with larger added 1s as safety, being without BMS support. (4.5 packs = 10lb - $112.50)
This will give me (11x 3.72V) 41V "full" and (11x 3.5V) 38.5V "empty". Now that is a performance differential that I can live with.
Compare to above

Image

This would give me near 10Ah for daily use, with a nice safety buffer towards empty and a massive additional 11Ah if I decide to "fully charge" to 46.2V for some long trip?. ( I built and charge with "MeanWell Mega-mod" S-150-48 modded with dual meter and dual external pots for 29-54V, 0-5A adjust ability)

The 15-60% cycle, within the best energy rich voltages, and the large pack ensuring low C - rate should provide a very long life with stable performance throughout each cycle! (near the voltage stability of LiFe)
.
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 » Dec 13 2019 7:12am

.
...
Resurrecting "dead" ( extreme low voltage Lithium cells ? )

Bought a quantity of Ryobi 20V and 40V batteries for recycling cells.
I was at 1st dismayed to find none that would charge in oem chargers. Listed as for cell acquisition but still ... well, started opening packs and found cells were very empty, not like 3.0V, more like 0.3V-0.1V. Spent some good money, so stated charging 10s2p and 5s1p at .1A with the NiMh setting on my iMaxes. Monitored cell voltages and saw a nice gradual and equal voltage progression.
Note: 0.1A charge as recommended for optimal cell rejuvination and as a safety factor to negate the energy needed to initiate thermal runaway. Low energy input can "safely" dissipate as "warmth" rather than "heat".
WARNING: Any charging of "questionable" cells or batteries should be conducted in fireproof and well ventilated area! Do not leave unattended!

Now this flies against the accepted recommendation that deeply discharged cells are damaged >> destroyed (also unsafe, but not factored ... yet), but continued to watch till cells progressed to a fairly equal 3.0V each (13 of 20 - 7 with "bad!" 0.0V cells). Then I placed the 5s1p Ryobi into their oem charger and was surprised when 12 of 20 charged to good capacity >> tested in drill. Then I manually fine tuned, equalized, voltages at the oem 4.08V. Had no 40V 10s2p charger, so after reaching 30V I placed packs on a MeanWell at 41V 2.5A "charger" and was able to metered charge 13 of 14 batteries to nice equal oem 2.6Ah fullness. All presently display the 4 LED "full" on their indicators.

Does this mean that deeply discharged cells are still safe and usable?
I would say a tentative ... some - "possibly" ... please note that these cells are very high output 1300mAh and 1500mAh INR* type cells.
And I will monitor for self-discharge and actual capacity before placing "in service".

Have a large selection of Ryobi 20V, so nice to have another dozen low capacity packs. Sadly, I have no 40V tools or charger, so can't test or charge the 40V batteries as intended, the batteries have protection that won't allow non-oem charging through the voltage terminals, some thermal safety, gauged resister or such through the additional contacts? Easy to bypass all BMS functions but will more likely add an external neg charge point. Probably use will be to parallel 4 and put into 36V SLA battery shell of electric lawnmower. Should retain balancing and LVC functions. 10.4Ah Lithium replacing 7Ah SLA for an expected 300% run time!

* INR = Lithium Manganese Nickel
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 » Dec 14 2019 1:21am

.
...
36V 5.1Ah "bricks" @ $24.99

Look to be of excellent quality. Annoying is the prevalent LEDs,
Shipped at precisely 3.60V, BMS has a blinking blue LED, charging presents a blinking red LED and charged to 42.0V has a constant blue LED.
Monitored charge through the charging leads shows a pulse type charge that looks to stress MeanWell power supply and is liable to take an extended time to charge so I charged @ 2,5A through the output leads for a much smoother, presumably quicker, charge.

1st test charge was 3.65Ah from 36.0V to 42.0V for 2p or 1825mAh from 3.60V.
Which looks to be ~100%+ rated capacity:

Image

Look like a good deal, my only concern is the prevalent LEDs, indicating the BMS is continually consuming some current?
Will use my Fluke, with 1/1000V metering to precisely monitor all cells on 1 as shipped pack and 1 freshly charged pack, for several weeks. (to determine energy drain)

Preliminary measure looks like I might be able to squeeeeze 4 into Watseka XP 8Ah SLA shell, using swastika pattern, for 20.4Ah? Tight enough might need to warm it up and make bulge a bit ... but worth it!

Price just jumped!
Bonus: just found 42V 5Ah Lithium charger with trimmable voltage for <$20!
$20.99 alternate listing = best price! Check seller listings for various chargers , some with voltage trimmer, search "13s", "14s" or "15s" etc.
.
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 - December 2019

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Re: Homemade Battery Packs

Post by john61ct » Dec 14 2019 5:13pm

I believe not all their chargers feature "autostop".

To me that's a power supply not a charger

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DrkAngel   100 GW

100 GW
Posts: 5316
Joined: Dec 15 2010 11:14am
Location: Upstate-Western-Southern Tier NY. USA

Re: Homemade Battery Packs

Post by DrkAngel » Dec 16 2019 7:19am

DrkAngel wrote:
Dec 14 2019 1:21am


Price just jumped!

Bonus: just found 42V 5Ah Lithium charger with trimmable voltage for <$20!
$20.99 alternate listing = best price! Check seller listings for various chargers , some with voltage trimmer, search "13s", "14s" or "15s" etc.
.
Price keeps changing, with various % discounts, many, presently, < $20!
Price went up? - Check back later!

Highest voltage is up to 84V 23s = 96.6V @ 3-8-15A!
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 - December 2019

EBike Toolbox - Bargains! $

Endless Sphere Wiki - Lost?

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DrkAngel   100 GW

100 GW
Posts: 5316
Joined: Dec 15 2010 11:14am
Location: Upstate-Western-Southern Tier NY. USA

Re: Homemade Battery Packs

Post by DrkAngel » Dec 17 2019 9:03am

DrkAngel wrote:
Dec 07 2019 10:49pm
Finally received shipment notifications on all items ...
Plenty of projects to help keep me busy through the long cold Winter.
DrkAngel wrote:
Dec 07 2019 6:36am
.
...
abbondanza

Receiving a wealth of battery potential!
Battery Hookup (alarmhookup on ebay) had-has a great discount on some recycled batteries.
36V 5.1Ah BMSed batteries, as low as $24.99 each (for 10x quantity) - got 12
Have 5 36V compatible eBikes
8Ah LiPo cells 25-50C discharge and 15C charge $4 each - got 31
48V 1000w hub kit needs POWER! 14s2p with 3 spares or 15s2p with 1 spare?
Ryobi 40max 3Ah for $6 - parts or repair - got 12
Need something to play with, try to resurrect packs ... then buy Ryobi 40V tools? or parallel for 36V eBikes? or my 36V SLA mower?
Ryobi 18V 1.5Ah batteries - parts or repair - $1.50 - got 20
Got lots of Ryobi 18V tools, resurrect or scavenge cells to rebuild some packs?
9s2.89Ah LiPo modules in fireproof shell @ $4.99 - got 6
Will reassemble as 3s3p for "12V" 8.67Ah modules

Much more available and sale still going on (12/7)
https://batteryhookup.com/ overwhelmed with sales - expect delivery delays!
No, I am not affiliated, just spreading the good cheer ...
36V 5.1Ah BMSed "bricks":
appear of good quality , designed for Segway scooters, May have to remove BMSs to fit 4 (36V 20.4Ah) in eZip oem 10Ah SLA battery shell, can "swastika" 4 into Watseka XP 8Ah SLA battery shell - for 36V 20.4Ah. Both have room to push to 11s for 36V 10Ah "performance" battery = minimal voltage sag & extreme life!

8Ah 200A LiPo cells:
15s2p capable of 400A output for eMotorcycle.
Way more output power than needed but capable of 5 minute to 90% charge! Requires massive charger and high voltage-Amp mains power.

Ryobi 40V Lithium 2.6Ah batteries:
13 of 14 restored, all metered near 100% on direct to cells charge.
Ordered 40V charger to confirm on board charging circuit functional.
Output terminals will not charge except with oem charger, possibly using additional terminals to activate charging pathway?
Can path charging wire from battery neg to external charge point for paralleling batteries into eBike, or other? Will manually charge but BMS will still control balance and LVC.

Ryobi 20V 1.5Ah:
12 of 20 restored via internal charge at cells.
Charged to ~3.0V per cell then finished in oem charger.
Capacity not metered but all cells charged in near perfect "balance" indicating reasonably good condition?

9s 2.89Ah LiPo modules:
Took partial charge, will need to crack open to safely monitor and charge ...
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 - December 2019

EBike Toolbox - Bargains! $

Endless Sphere Wiki - Lost?

User avatar
DrkAngel   100 GW

100 GW
Posts: 5316
Joined: Dec 15 2010 11:14am
Location: Upstate-Western-Southern Tier NY. USA

Re: Homemade Battery Packs

Post by DrkAngel » Dec 20 2019 4:25am

DrkAngel wrote:
Dec 17 2019 9:03am
36V 5.1Ah BMSed "bricks":
appear of good quality , designed for Segway scooters, May have to remove BMSs to fit 4 (36V 20.4Ah) in eZip oem 10Ah SLA battery shell, can "swastika" 4 into Watseka XP 8Ah SLA battery shell - for 36V 20.4Ah. Both have room to push to 11s for 36V 10Ah "performance" battery = minimal voltage sag & extreme life!
EVE 10s2p 36V 5.1Ah bricks come nicely balanced @ ~ 3.60V.
Of concern is a constant LED blinking.
Charging port supplies pulses of charge from my MeanWell power supply, so altered charge to power output for nice smooth charge.
Blue LED turned constant LED as charged topped off near 42V and cells were near perfectly balanced in 2 different segments. 1 segment of 5s2p was within 1/1000V, the other was within 1/000V but ~1/100V lower than 1st segment. Very good but "different"?

BMS does draw some noticeable power!
After several days, 1 battery dropped below 41V and LED began blinking again.
Guess I can't recommend using BMS, if subjecting to any prolonged storage!
Balance function seems excellent though ... might leave 1 BMS and parallel 6s more of bare cells for a 10s8p 36V 20.4Ah build.
Bricks are ideal for simple BMS removal, leaving nice connected cells for simple reassembly!

Will charge all bricks and monitor voltage drop. any with faster "drop" will be recharged, BMS removed and cells monitored for self-discharge.

Preliminary charge , from 36V to near 42V difficult to determine actual capacity but guesstimate near 100% capacity, will discharge 1 brick to 33V for a capacity charge test.
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 - December 2019

EBike Toolbox - Bargains! $

Endless Sphere Wiki - Lost?

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