HK Lipo Bricks - what do I choose and why?

Hillhater said:
Another member used those 4cell holders to build a large pack.
There are some learning points in there for you.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=70605&p=1089157&hilit=Battery+case+box#p1089157
Click to expand...

That was a good read. Thanks for posting it.

Hmmm...so maybe I will have hot battery holder issues. He built his where there are 8 cells in parallel and using the solder pin out the bottom was the current transfer point and probably also the source for the heating issues. Once he ran a copper wire across the tops of the battery clips, he had no more heating issues. I'm using the same pin, but there's only one cell feeding through each pin. I don't know yet, but maybe, I'll be OK. His packs are "wide" and then connected in series. Mine are "thin" and connected in parallel. It might make the difference...we will see. Also, I will have dual 18 awg wires running between cells...that ought to help too. Worst case, I drop a small piece of copper wire over the pins and beef them up a little. I'll definitely watch out for this possible issue, but it's easily resolved too. If there is one thing I have tons of...it is copper wire.

Ventilation and cooling may be an issue for me. I think a small readily available louvered vent cover in the front and back of the box will do the trick and of course a fan or two. I have several temperature controlled fan controllers that run off of 12 volts. I conveniently have a DC-DC converter in my scooter that outputs 12 volts. The converter turns off via a simple mosfet switch tied to a 5 volt line on the speed controller. It would be super easy to run that 12 volts out to the back deck to run the fans. When the key gets turned off, it disables the motor controller which then drops the 5 volt line and shuts off the mosfets. It's worked quite well and my key-off current draw is 10mA. In a weeks time, I don't even notice that much draw on my batteries.

On an up-note, he was pretty happy with his battery holder solution and said it was working well with more range/capacity than his SLAs (ugg!). I think with solar cells slathered all over his bike he would have done better than SLAs...OK...slight exaggeration. He confirmed that the cells were not vibrating out of the holders which is great news. I was wondering if vibration would wiggle them loose, but apparently not.

After a while I need to just make a thread for this build. This was originally about LIPO R/C packs and it evolved into this build. LOL

Hey Circuit! I ran across your thread on battery holders of some kind, but there were no pictures. Can you post them up somewhere please?
 
If anyone is interested,,,DrkAngel posted a good thread on testing batteries here.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=53017#p788170

I've used his method 2 in a modified way to find weak cells.
 
999zip999 said:
I'm thinking this battery pack good for 4 amp discharge ? Why a 130 amp controller ?
Click to expand...

LOL...times 7 and then 3 8000mah LIPO packs.
 
My existing lipo's are completely redone into 20S1P packs now. And there's room in the box for a third pack so I have ordered more 8000mah LIPO cells. I can't fit enough 18650's in there to make a significant difference so I decided going with more of the same cheap LIPOs was a better use of the space considering how I would get 8000mah of capacity at 20S1P that fits perfectly in that space. The cells I bought are $9 each shipped to me. Admittedly they are 3C discharge, but that's easy to overcome with multiple parallel packs. Still 24 amps per pack is respectable and I ran half of last year with 3 of them and then later added a fourth pack since I had the space. I just looked on HK at the 10C LIPO packs. They have a higher discharge rate, but I'm still half the price per cell for what I bought and I won't typically exceed 2C per pack anyway. Unlike the HK 10C packs which are really more like 5C, I know these cells will legitimately do 3C. I can do 72 amps from the LIPOs and the LION packs are a bonus on top of that. Conservatively 2 amps per LION pack is 14 amps (7 packs). I think 86 amps will get me where I need to go! with my old controller I could only pull 40 amps and that was while going 32mph up a hill. I will have doubled that in capability or more and increased the voltage to 72 volts. I should be A-OK for speed, but range might be an issue. With 4 LIPO 12S packs, when they were new, I was able to go 24 miles on a charge and that was riding hard. Capacity has dropped off with time and use. If I can get 15 miles...that will be more than enough. I really only need 10 miles to make the round trip from home to work to home again.

I received the 5S balance cables last night so I added them to my rebuilt LIPO packs and then closed them up. About 6 months ago I made 2 6S balance charge cables that included banana connectors from when I was running off of 12S packs. I used them for balance charging my LIPO packs and for charging 18650's 6 cells at a time. I'll need to make several 5S balance charge cables so I can use my many R/C chargers simultaneously when I want to balance charge all my new packs. I have another idea percolating around too. I can buy a single 20S BMS and adapt its balance connectors to work with my 5S balance connectors. That way I can balance an entire pack all at once and use my 84 volt battery charger. The same BMS will work on all the LIPO and LION packs and be lots cheaper than buying BMS's for each pack. It will be used once a month or so anyway so this might be a great time saver for balancing cells all at once. Most charging will be done without it.

20S%20LIPO%20packs%20Complete_zps58jbmzf0.jpg
 
I'm moving off this thread since this was originally about HK lipo packs and starting a new one that's specific to my battery builds. If you see a lot of repeats of stuff I wrote on the new thread it's because I'm going to do a lot of copying and pasting.
 
Hi Guys,

I recently killed my Batteries (discharged to zero while gone for some weeks) and was looking for a suitable replacement.
So I have read this thread and want to thank everyone who contributed!
Particularly it was enlightening to see the comparison of LiPo-Bricks to 18650 cells.
I have ordered 120 Sanyo 18650 GA cells now to replace my dead Lipos.

Of course Murphy's law dictated that a super-attractive offer would pop in the next day ;)
I thought you might want to take advantage of this while it lasts:
BUT NOTE: This is only a 2C pack, so only suitable for commuter-bikes not hot-rods...
http://www.hobbyking.com/hobbyking/store/__77791__Multistar_High_Capacity_Lightweight_4S_6000mAh_2C_Multi_Rotor_Lipo_Pack_UK_Warehouse_.html

lipo-hk-sale.png
Here is a overview table I have made for myself to compare the different solutions,
Sorry that it is a bit chaotic and a messy.
batt-comparison.png
As you can see I can build a similar battery pack to what I had before for half the price with this special offer.
Before: (Column 1) Zippy 6S/8000: 1066Wh for 390Euro
Offer now: (Col 5) Multistar 4S/6000: 1332Wh for 201Euro!
Sure, the big difference is of course that one is a 30C pack the others are 2C, so the comparison is not very fair...

The comparison also shows that the lightest and smallest (volume) pack will be the one with the 18650 cells.
And given that members here say that one can expect at least 2 times the cycles out of these cells, the price is still very attractive.

Cheers, Ulli
 
I read interesting thread on ES about Multistar batteries.
I am a little disappointed about factual “C” of Multistar batteries (max. 2,5C, no stated 10C)
I think about some upgrade on my ebike.
Now I have:
Canyon DH frame, Rock Shox Boxxer, 200mm travel, 19 x 3`` tires, max speed about 60km/h on the flat
Cromotor V3
Kelly KLS7230S controller
http://kellycontroller.com/kls7230s24v-72v300asinusoidal-brushless-motor-controller-p-1343.html?osCsid=au7tfk6i1k4le5farblqjuiaq2
Battery LiFePo4 72V nominal (24s 3.2V 15Ah 3C WINA)
http://www.ev-power.eu/WINA-30Ah-100Ah/WINA-LiFePO4-Power-3-2V-15Ah-aluminium-case.html
+ Cycle analyst V2
I supposed to replace my LiFePo4 battery by 20s LiPo Multistar battery (2x 6S + 2x 4S 20Ah). Will there be any improvement? Now I have on CA max. 80-100A, continuously about 30-50A.
I use my bike first of all off road. I don`t need the highest speed, I need controlled power on the hills.
I am not commuter. More likely high power guy. :D What battery should I go in?
Thanks. Karel
 
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