LG ICR18650D1 battery pack build

LSBW

LSBW

100 W
Joined
Sep 30, 2012
Messages
298
Location
Toronto, Canada
Inspired by these guys, http://electrotransport.ru/ussr/index.php?topic=8660.msg322126#msg322126
I've decided its time to upgrade from crappy konions and get some real stuff.

I've got 200 pcs of LG ICR18650D1 from this lady http://www.powertrading.com.pl/?page_id=4&lang=en
Cost with 3 days delivery to Canada by UPS was $800.

I've made 2 of 10P6S bricks and 1 of 10P8S brick.
Should be good for 87 volt and 30 Ah, once I get a hold of 87 volt bulk charger.

LG-ICR18650D1_1.jpg


Finished battery pack:

Ready-pack-LG.jpg


Yesterday was first test of my new LG battery pack:

Start voltage 84 volt
End voltage 74.5 volt
Distance 68 km
Used 17.62 Ah
1312 Watt-hours
19.1 Wh/km
48 Amp max
Max speed 63 km/h
Average speed 28.8
Pack weight is 10 kg and it fits into 400x150x100 mm box
Bike weight is 42 kg or 90 lbs.
Lyen 18 FET controller (limited to 45 Amp battery) and Cromotor in 21" wheel.

Most of the riding was in city with stop and go traffic.
I did big hill climbing (100 m over 1.2 km) around 4 PM and then headed straight home, 28 km thru city.

[youtube]CJbXNziUK1k[/youtube]

Pretty impressive, except for one thing, battery pack was very warm in the end.

One more thing, please do not compare this to HK lipo, as it is useless for me.
 
According to the product spec these cells have 300 cycles to 75% capacity at 0.2C discharge rate
http://caxapa.ru/thumbs/406271/LRB-PS-ICR18650D1.pdf

For a 800$ pack it means 2.6$ / journey
 
It is a valid point. However, 300 cycles times 70 km equals 21.000 km
And yesterday's ride was pretty brutal, I've never assaulted my bike or battery like this before.
I'm pretty sure I can get 100 km on a single charge.
Since March of this year I've done so far on my bike 1300 km.
Let's say 220 km/month, most of it is my work travel, 10 km round trip or 200 km/month

If I continue at this rate, this battery will be good for 95 month, or 10.5 years, since I usually don't ride in Dec, Jan and Feb.
So, never mind 10 years, if this battery will last 5 years, I'll be very happy ebiker.
 
cwah said:
According to the product spec these cells have 300 cycles to 75% capacity at 0.2C discharge rate
http://caxapa.ru/thumbs/406271/LRB-PS-ICR18650D1.pdf

For a 800$ pack it means 2.6$ / journey
Click to expand...

yet at 75% of remaining capacity the cells still have an energy density of 173WH\KG compared to the starting energy density of lifepo4 of about 100wh/kg.

Also remember that with these cells they have great compression and manufacturing quality which equates to much improved shelf life compared to most cheapo lipo packs.

Honestly though he paid quite a lot for his cells 8 dollars a cell is too much in my opinion i would have personally gone with a Samsung INR18650-20Q 15A rated output per a cell but still with a energy density of around 167wh/Kg and for his application when built into the same size pack they would handle the 48A load much better without getting hot.
 
chilledoutuk said:
cwah said:
According to the product spec these cells have 300 cycles to 75% capacity at 0.2C discharge rate
http://caxapa.ru/thumbs/406271/LRB-PS-ICR18650D1.pdf

For a 800$ pack it means 2.6$ / journey
Click to expand...



Honestly though he paid quite a lot for his cells 8 dollars a cell is too much in my opinion
Click to expand...

Actually, it was $4 per cell, I've got 200 cells in total for $800, pls see my first post.
 
LSBW said:
It is a valid point. However, 300 cycles times 70 km equals 21.000 km
And yesterday's ride was pretty brutal, I've never assaulted my bike or battery like this before.
I'm pretty sure I can get 100 km on a single charge.
Since March of this year I've done so far on my bike 1300 km.
Let's say 220 km/month, most of it is my work travel, 10 km round trip or 200 km/month

If I continue at this rate, this battery will be good for 95 month, or 10.5 years, since I usually don't ride in Dec, Jan and Feb.
So, never mind 10 years, if this battery will last 5 years, I'll be very happy ebiker.
Click to expand...

Good answer! I just hope that using almost 10 times the standard discharge rate (0.2C) will still give you at least 200 cycles. And there is also the calendar life but nobody knows.

Do you use a BMS? Was it difficult to solder the pack together?
 
This was posted before, notice Panasonic NCR18650B 3400 mah right below LG D1:

HighEnergy-5.0.png


I have dual Hyperion 1420 for charging and CA 2.3 for monitoring pack while riding, also my controller cuts off at 63 volts, to limit discharge voltage.
Soldering was pretty easy, I've used Weller SPG 80L, silver bearing 1.6 mm SAC800 solder wire and lead free solder paste, 10 AWG single strand household copper wire for pack connections and 18 AWG Turnigy wire for balance taps.
Took me one evening and couple Buds to do one 26 volt brick :)
Saving me at least $200 in process per each pack, if I had it ordered with welded tabs.
Which you still need to solder in series and add balance wires too.

More graphs, not sure how meaningful these are, looks like made up by LG PR people :)

cycle.png


dis.png


discharge-slope1.png


Courtesy of http://e-motion.lt/
 
So a bit of solder paste and a 80W solder iron is all you need to solder these cells together?

Why do you need solder bearing (http://www.ebay.co.uk/itm/Silver-bearing-resin-cored-solder-1-6mm-LEAD-FREE-1metre-/180750372719) and solder wire together? (http://www.amazon.com/Bernzomatic-SAC800-8-Ounce-Bearing-Acid-Core/dp/B0002JM8BS)

I might try what you do but with a BMS
 
You mean silver bearing solder and solder paste? I've been soldering various doohickeys since at least 1980, and found it to work better, but its just IMHO.
 
ok ok, if just using solder paste is enough to solder on the cell tab it's perfect. I should give a try. I'm just a bit concerned about cycle life but... ahah who knows..

Why did you choose these LG over other cells? cheaper?
 
I have considered these LG cells also and bought a couple last year to test. The capacity was decent and the voltage higher than most cells. However I just found a data sheet from LG and noticed that the discharge rating below a temperature of 5 deg C is only .5 C or 1450 mA. From 5 to 45 deg C it is 2C or 5800mA which is decent. This would be a problem in cool weather.
It may be necessary to limit the current when below 5 deg C until they warm up.


Data Sheet:
http://caxapa.ru/thumbs/406271/LRB-PS-ICR18650D1.pdf
 
.
 
Park battery outside of house or garage, Not in or under. Look with a loop as hot solder and cold joint's may make snow balls of solder landing under post's ect. ?
Plus amp. limit = battery life.
 
Hillhater said:
999zip999 said:
P..... Look with a loop.....
Click to expand...
???? what is a "loop" ??
Click to expand...

I believe that is like a Jewelers Loupe, which is a magnifier for one eye in a tube format.
otherDoc
 
Here you go. Not sure what you have in UK

http://www.homedepot.ca/product/soldering-paste-flux-50g/959954

http://www.canadiantire.ca/AST/brow...2P/Bernzomatic+Acid+Core+Solder.jsp?locale=en

http://www.amazon.ca/Weller-SPG80L-Marksman-Stained-Soldering/dp/B006KBLKIE

Make sure soldering tip is always clean and has enough solder on it.
I've had zero problem soldering various laptop, konion and LG batts. Good luck.

Which one are you using to solder aluminium?
Click to expand...

Aluminium? I don't think 18650 elements have any AL parts.
 
how are the cells holding up?

If the pack is getting very hot new, it may be an issue when they get more cycle as resistance will keep increasing.

Just wondering if the pack can still be used after 50 cycles.
 
I did a destruction test on some dodgy 18650's that were included with some lights that I bought.

Basically I soldered a few cells together using a large and very hot soldering iron. I could hear the inside of the cell I was soldering boil on the negative side. Just saying be careful as boiling inside a cell can't be good for it.
 
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