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 » Tue Apr 25, 2017 9:27 pm

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Solution to my batteries of various voltages, cheap throttle is 3s-23s compatible, but battery requires voltage monitoring due to controllers fixed LVC.

Found some interesting throttles ~ $12 each

12V-99V Electric Scooter E-Bike Throttle - $12
Handy
voltage monitor
and
throttle key lock!
Update - Red LED is worthless in bright daylight!
Key switch was not reliable through LED circuit, but spare wire can be used as positive key function.
(Waiting on 2nd sample for disassembly and alternate wiring. will document ... have blue LED that might replace for better visibility.)

Image

Left hand 12V-99V throttle with 3 position switch, as turn signals or other? - $12
Received right hand with on\off switch = bad listing but got free after struggled for refund.

Image

See - EBike Toolbox - Bargains! $

Solution to my batteries of various voltages, cheap throttle is 6s-12s compatible, but requires voltage monitoring due to 21V LVC.
Last edited by DrkAngel on Sun Jul 02, 2017 1:18 am, edited 2 times 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
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Re: Homemade Battery Packs

Post by DrkAngel » Sun May 07, 2017 8:39 pm

.
...
I know ... hardly a "Homemade Battery Pack".
But, it is a combining-re tasking project.
Best of all it is a substantial performance, capacity, durability and price improvement over the oem offerings!
DrkAngel wrote:
Floureon 7S 5000mah 25.9V 40C Lipo Battery <$60
delivered from USA


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

1 $60 brick = capacity of $120 SLA pack
2x ($120) = capacity of $570 10Ah oem Lithium RMB battery
4x ($240) @ 10lb = 2x $570 10Ah oem Lithium RMB battery or 4x $120 (65lb) SLA
(4x leaves room for 22mm x 650mm x 150mm BMS)

7s BMS ≥$9
$9 20A continuous has 30A surge ...
might be adequate for 350-450watt motors in typical use?

Important!
Quality of cells not yet determined.

Sample ordered!
Will test for self-discharge and matched capacity ...
Will update after received and tested.

If of very good quality ... will add single brick to next 18650 recycled laptop cell build to improve pack IR, surge capability.
.
Update: 1st sample looks extremely good.
Battery came with all cells within 4/1000th V.
After charging and balancing, let set 4 days and no cell lost even 1/100th V.
Look to be good quality ... ordered up 4 more packs and will conduct capacity, IR tests next.
Everything looks good enough that I will build a capacity map to pinpoint optimal charged and discharged voltages.

If all test prove out will order in quantity for several 25.9V eZips, upgraded to 25.9V (24V) electric mower and as 14s (51.8V) for 48V rear hub eBike.
Last edited by DrkAngel on Sat May 13, 2017 7:47 pm, 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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TheBeastie
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Re: Homemade Battery Packs

Post by TheBeastie » Mon May 08, 2017 2:33 am

DrkAngel wrote:
Floureon 7S 5000mah 25.9V 40C Lipo Battery <$60
delivered from USA


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 ...

http://www.ebay.com/sch/i.html?_from=R4 ... Po&_sop=15
Wow that does look nice. Nice thick size for 5000mah lipo if I remember correctly. Also those balance tap wires look really thick and solid as well.
Sometimes I wish Australia could invade and take over America so I could enjoy such convenient purchase options.

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Re: Homemade Battery Packs

Post by DrkAngel » Mon May 08, 2017 7:07 pm

And ... just found another great 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.
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 "LCD blackage"?
Last edited by DrkAngel on Thu May 11, 2017 8:57 am, edited 1 time 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.

New & Improved - Acronym Definitions

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markz
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Re: Homemade Battery Packs

Post by markz » Mon May 08, 2017 7:12 pm

You gotta link for that Smart Battery Meter

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Mon May 08, 2017 8:08 pm

Oops ... sorry. Smart Battery Meter with low voltage alarm!!!
DrkAngel wrote:.
...
7s add-ons

7s LCD battery meter
Fuel level meter
Monitor cell voltages
IR tester (questionable accuracy)
Balance function (overheated in latest test!)
Image

Better selection - 5 in 1 Smart Battery Meter - ~$7
Black model not the same = crappy!

1-8S Lipo Battery Low Voltage Tester Buzzer Alarm <$2
Programmable, individual bank LVA- Low Voltage Alarm
Displays pack voltage then individual bank voltages
Use multiple for larger packs. 2 for upto 16s, 3 for 24s etc.
I ran to front bars using 8 wire Ethernet cable (7s 25.9V Li-ion)
Use as voltage meter only, hook to wires going to 24V leds on throttle. (30V max)

Also, now, comes in hard case shell
Image

7s BMS ≥$9
$9 20A continuous has 30A surge ...
might be adequate for 350-450watt motors in typical use?

Note: Low cost items of varying accuracy! Some bank readings can differ by hundredths. Test before relying on!
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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markz
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Re: Homemade Battery Packs

Post by markz » Wed May 10, 2017 7:03 pm

Homemade Battery Packs would be better built then stuff bought online. Because 1) you made it and know how its made and 2) you know exactly what bms you are using and if its good quality and 3) you use quality materials and do not skimp on things to make an extra buck like perhaps some online retailers might do who live oversea's.

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Wed May 10, 2017 10:54 pm

I take a great deal of care to test cells for self-discharge, capacity and IR.
My past half dozen builds, with recycled laptop cells, have retained good balance for hundreds of bulk charges ... with no form of BMS.

RC high output LiPo are designed for high output and a comparatively brief life.
Matched cells with no self-discharge at moderated charged voltage and discharge rate could prove reliable and durable!

Such a bargain ... I feel extra thorough testing to be worth the effort.
Received 5 bricks ... undergoing various stages of testing, before use.
Looking very good, so far, but still have capacity test to complete, before duty trials.
1 spare pack?
Personally, I am not afraid to shuffle cells ... if necessary!
Last edited by DrkAngel on Thu May 11, 2017 1:49 pm, edited 1 time 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.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

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RollinB
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Re: Homemade Battery Packs

Post by RollinB » Thu May 11, 2017 12:53 pm

Tesla 18650 (p90) cells , thanks to the great service of Edison Motors via JD, kudos!
12s8p
48v 27.2ah.
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riba2233
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Re: Homemade Battery Packs

Post by riba2233 » Thu May 11, 2017 1:19 pm

What is that black goo? How are cells going to vent underneath that?

RollinB
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Re: Homemade Battery Packs

Post by RollinB » Thu May 11, 2017 1:38 pm

The black goo is liquid electrical tape.
I am monitoring cell temp, so far no issue.

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Re: Homemade Battery Packs

Post by Hillhater » Fri May 12, 2017 2:00 am

RollinB wrote:Tesla 18650 (p90) cells , thanks to the great service of Edison Motors via JD, kudos!
12s8p
48v 27.2ah.
Do you have any cell test data ?
Discharge graph, capacity , DCIR measurements. Etc
Hard data for Tesla "P" cells is not easy to find.
This forum owes its existence to Justin of ebikes.ca

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Re: Homemade Battery Packs

Post by RollinB » Fri May 12, 2017 9:49 am

I am away from home, for a while. I will get BigB to submit data.
I used two full cycles before I left. What I found was
Start V =50.4. (Cycle analyst low V cutoff set to 40v
Max amps;(dead stop-full acceleration to top speed of 53kms/hr) was 48a
Used 16Ah to go 40kms. Dropped to 40.8 v.
The second cycle, capacity increased.
Start 50.4v.
Max amps 48.*a top speed 54 km/hr
Used 22 Ah to go 67 kms
Volts dropped to 41.3.

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Re: Homemade Battery Packs

Post by RollinB » Fri May 12, 2017 10:48 am

Temp never reached higher than ambient temp. Was 27•c that day.

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Re: Homemade Battery Packs

Post by RollinB » Fri May 12, 2017 1:51 pm

Update;
50.4 v start, max amp 48 pulled.
13.4Ah used. 56.4 kms. Only dropped to 44.3 V
Would seem that the capacity increases every cycle at this point.

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Re: Homemade Battery Packs

Post by Hillhater » Fri May 12, 2017 4:53 pm

Ideal is single cell test data .
But thanks, any data is good. :D
This forum owes its existence to Justin of ebikes.ca

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riba2233
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Re: Homemade Battery Packs

Post by riba2233 » Sat May 13, 2017 2:23 pm

RollinB wrote:The black goo is liquid electrical tape.
I am monitoring cell temp, so far no issue.
I was thinking in event of some kind of failure, not in normal use.

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Re: Homemade Battery Packs

Post by Kapalek » Mon Jun 05, 2017 1:19 pm

An example of soldered cells and not very tidy pack example.
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Re: Homemade Battery Packs

Post by DrkAngel » Mon Jun 05, 2017 10:04 pm

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++.
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Works OK but, since I run as a mulching mower, the extra rpm and torque seems advisable.
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.
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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!

Home Depot finally has the 20" mulching blade available again so will get a spare, only $9.95 for the Homelite cordless mower.
Straightened and filed the worst nicks out of the old blade but new blade will probably improve even more.

Cells are surrounded and set upon closed cell foam.
Prevents movement and protects from vibration and rough handling.
At probably less than 1C discharge, I am not worried about battery heat.
Last edited by DrkAngel on Sun Jun 25, 2017 11:13 am, 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.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Tue Jun 06, 2017 7:58 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 possibly 25Ah+.
7s = 116.66% capacity with 116% torque and speed
Will confirm bank "comparative capacity" by bank voltage level after partial discharges, in steps.
8 x 9 x 2" space above battery to add cells to any bank, if needed
1 charge at 6s mowed store grass area several times 3-4 mows per charge, with no cell ever dropping near 3.70V

This is my 1st large battery using the Sony LiPo (from Dell media bay batteries).
They have an excellent capacity profile with 90% capacity at 4.10V and a 75% capacity at 4.00V. (4.10 looks optimal and might outlive me - these are 8-10 year old cells that have maintained excellently!)
This could produce 1000's of cycles at still double the oem SLA usable capacity.
Might have to sell to industrious youngster with daily mowing route - in city = lots of small yards.
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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miro13car
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Re: Homemade Battery Packs

Post by miro13car » Wed Jun 07, 2017 2:01 pm

[quote="DrkAngel"]And ... just found another great 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".

[img]https://endless-sphere.com/forums/downl ... ?id=214962[/img]

How can this gadget shows capacity/real capacity/ by measuring voltages of cells.
Real capacity is shown by measuring charge going into battery .

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Fri Jun 09, 2017 4:05 am

miro13car wrote:Image
How can this gadget shows capacity/real capacity/ by measuring voltages of cells.
Real capacity is shown by measuring charge going into battery .
It does not show "capacity/real capacity".
It roughly estimates percentage of capacity based on arbitrary empty\full voltages of lithium-ion cells.
E.G.
Image

Not precisely accurate, more a yardstick method that does not reflect the newer technologies of 3.2-3.4V discharged voltages.

.
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

EBike Toolbox - Bargains! $

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Mon Jun 26, 2017 9:03 pm

Bulk cells for build. $231 \ kWh
DrkAngel wrote:.
...
20 "new" Samsung ICR18650-22P cells for $34.99

In a 10s2p 36V 4.4Ah "brick", With BMS!
BMS type varies
XT60 connector

Image

Intend on use as:
supplemental cells in laptop cell 7s 25.9V pack builds as buffer for surge demands
2, or more packs, in 36V cordless mower + 2600mAh laptop cells
For 36V front hub bike
As rebuild for 2 x 5s2p "18V" Ryobi, or similar, 4Ah packs - upgrade to 4.4Ah with 20A continuous 50A surge!

.
Bulk Price

200 Cells - $249.99 - $165 \ kWh
2200mAh 10A continuous - 20A surge

Large Bulk Price

1000 cells - $1100 $135 \ kWh

.
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

EBike Toolbox - Bargains! $

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cheapcookie
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Re: Homemade Battery Packs

Post by cheapcookie » Wed Jun 28, 2017 1:36 am

DrkAngel wrote:Bulk cells for build. $231 \ kWh

Bulk Price

200 Cells - $249.99 - $165 \ kWh
2200mAh 10A continuous - 20A surge

Large Bulk Price

1000 cells - $1100 $135 \ kWh

.
I have seen this offer before, doesn't look bad at all, I might it a try.

How are the floureon cells ?

Are they really 7s and not 6s ?

How much do you pay a $/KWh ???

Thanks Bye

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DrkAngel
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Re: Homemade Battery Packs

Post by DrkAngel » Wed Jun 28, 2017 5:30 am

Floureon LiPo deal all gone.
You snooze you lose!

Samsung 18650 deal ...
Same seller has similar deal wit LG brand cells! ... if preferred.
18650 cells 10s2p 36V w/BMS
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

EBike Toolbox - Bargains! $

Endless Sphere Wiki

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