18650 pack build using plastic battery holders

Batteries, Chargers, and Battery Management Systems.
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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by www.recumbents.com » Oct 01 2015 1:58pm

I am abandoning the aluminum box pack build. Instead I am planning on using 18650 battery holders that hold 4 batteries in series or parallel. They look reasonably beefy. Revised plan is:

* Use the batteries in each holder in parallel.
* Add add bus bars to connect 12 of them in series.
* Mount them flat in a 3 x 4 arrangement on a sheet of Lexan.
* Pop-rivet sides on the flat sheet.
* Screw the Lexan top down.

It should be about 11" x 12" and about 1.5" thick. This will be easier to mount on my bike, and I'll also have a spot to mount the CC HV160 controller and the DC-DC converter, etc. As you can see below, a good mounting location will be on the shelf below the seat bag.

Image

Now I just have to wait an indeterminate amount of time for them to be shipped from Hong Kong.

I recently took this bike all apart, painted it rattle-can loss black, and am now re-assembling it.

-Warren
Last edited by www.recumbents.com on Nov 07 2015 6:56pm, edited 1 time in total.

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by 999zip999 » Oct 01 2015 5:26pm

Most never get to the plate and swing the bat. Thanks for sharing. Step back. Things will get clearer.

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by clockwork247 » Oct 01 2015 5:50pm

www.recumbents.com wrote:I am abandoning this for now as there are too many potential problems. Instead I am planning on using 18650 battery holders that hold 4 batteries in series or parallel. They look reasonably beefy. Revised plan is:

* Use the batteries in each holder in parallel.
* Add add bus bars to connect 12 of them in series.
* Mount them flat in a 3 x 4 arrangement on a sheet of Lexan.
* Pop-rivet sides on the flat sheet.
* Screw the Lexan top down.

It should be about 11" x 12" and about 1.5" thick. This will be easier to mount on my bike, and I'll also have a spot to mount the CC HV160 controller and the DC-DC converter, etc. As you can see below, a good mounting location will be on the shelf below the seat bag.

Image

Now I just have to wait an indeterminate amount of time for them to be shipped from Hong Kong.

I recently took this bike all apart, painted it rattle-can loss black, and am now re-assembling it.

-Warren
the holders are expensive IMO... I saw them but scrape the idea, I wanted a pack with tons of battery, and this will cost too much. I've seen some design using them and it's really nice.

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by markz » Oct 01 2015 6:17pm

Yeah those holders are expensive, lucky they are a bit cheaper on ebay but still works out to $0.50 for each battery. $0.25 for each connection.
For a 100 pc battery, thats $50 on a $300 battery or 17% of the cost.

Whats wrong with these?
http://www.batterysupports.com/battery- ... 53_57.html
Works out to $3 for 10pc 3x unit. So 30 connects, 15 batteries. $0.20. Plus shipping $11 for
supower 231.jpg
supower 231.jpg (129.35 KiB) Viewed 2749 times
But $8 shipping minus the 2650 holders. I dunno about their shipping speed. Would be good to know before I buy from them.

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by www.recumbents.com » Oct 01 2015 7:58pm

I agree, they aren't cheap and I probably could have purchased a pre-built pack for the cost of the cells and various other parts needed to build a pack. The items from supower are just battery holders. The ones I ordered have the spring tabs built in.

Image

Thanks guys I won't give up, just changing plans...

-Warren

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by markz » Oct 01 2015 8:13pm

Spring tabs for low power batteries, or low draw.

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by www.recumbents.com » Oct 02 2015 11:08am

I am planning to use copper sheet in front of them to create maximum beefyness.

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Re: Abandoned build of 18650 pack in an off-the-shelf metal

Post by markw » Oct 16 2015 1:30pm

In terms of holding the batteries together in configuration, are you opposed to using hot glue? I seen this used in multiple 18650 battery assembly videos and it seems to be very successful!
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Re: 18650 pack build using plastic 18650 battery holders

Post by www.recumbents.com » Nov 07 2015 6:32pm

The cell packs finally arrived. I think they were $12 for each pack of five 4 cell holders, with free shipping from Hiflungpoo. I have 15 holders now. Initially they sent me one pack of 4 cell holders and two packs of 3 cell holders and I had to post some bad reviews, etc before they acquiesced and send the other two packs of 4 cell holders. Fun.

To build this battery I will need 12 of these holders. Each battery holder will have 4 groups of cells in parallel, and the 12 cell groups will be arranged in a flat 3 x 4 array. I will end up with a pack that is about 12" x 9", and will be about 1.5" thick. This will fit well on the the rack of my ebike. The whole pack will be inside a box built of Lexan (polycarbonate). It will be nearly bulletproof.

I initially thought I would connected them using tabs made from copper sheet, but I decided that thick copper wire would be better. This is 14 gauge wire from a house wiring project. I bent clips to go between the tabs on adjacent battery packs.

Image

Next I soldered the clips to the tabs, and to a "bus bar" connecting all the cells groups in parallel. Not perfect but I think the solder connections are solid.
I was happy to see that these plastic packs are fairly heat resistant, and that the soldering does not make them melt down. They do melt but it takes a lot of high heat to do it.

This technique is much easier than the method I tried previously and abandoned. It will probably take about 10-12 hours to get the pack all soldered together.

Image

Here's a test fit of the batteries. They still fit (whew!). They are very tight, and will require a ribbon or a strip of cloth under each group of cells to make it easy to pop the cells out of the holder.
There will be three rows of four packs in series.

Image

The ends of each row will use some thick copper plate as a bus bar to connect to the next row, and as the main battery pack positive and negative terminal.

I'll post more in a couple days when the pack connections are done.

-Warren

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Re: 18650 pack build using plastic battery holders

Post by markz » Nov 07 2015 9:29pm

This is a clever idea, even without pre-bought plastic 18650 holders, which I find to be too expensive.
If I can find a way to make the holders, out of plastic, or wood then your bus bar idea would work for SURE!!!!

It gives me renewed hope for a solderless/tabless battery setup.

Have you thought about using duct tape, or something else to make the batteries absolutely secure, even with the tight fit they still could pop out.



I have to look into how to build holders, maybe I can buy a 3d printer. I have to look into that, I've seen cheap ones for sale and used ones.

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 07 2015 10:20pm

Markz - I will probably just use some foam or something between the batteries and the cover to ensure that they don't ever bounce loose.

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Re: 18650 pack build using plastic battery holders

Post by markz » Nov 07 2015 11:39pm

Yeah that will work, I didnt realize they had covers. RIght now I'm looking into Acrylic Sheets from HomeDepot and Acrylic Glue, 3d printers and cnc's are too pricey. Its hard to find that stuff, luckily I just found a place in town that sells it all. Rather buy local then pay extra to ship stuff in.

You are using 14awg solid copper for house wiring?

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 08 2015 8:04am

No, the battery holders don't have covers, I am building a polycarbonate cover for the entire pack. Yes I'm pretty sure that the wires are 14 awg. 12 awg is too thick for me to bend and solder easily. Did you already buy a bunch of loose 18650 cells? Half of the reason I bought these cell holders is for the spring clips. Those will be hard to make with any kind of precision by hand. Note that acrylic cracks pretty easily.

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 08 2015 10:09am

The ends of each row use some thick copper plate as a bus bar to connect to the next row, and as the main battery pack positive and negative terminal. It's pretty hard to solder to the thick copper.
The battery holders have nice slots to allow them to be fastened together with plastic wire ties. I'm about half done.

Image

Warren

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Re: 18650 pack build using plastic battery holders

Post by parabellum » Nov 08 2015 10:54am

markz wrote:This is a clever idea, even without pre-bought plastic 18650 holders, which I find to be too expensive.
If I can find a way to make the holders, out of plastic, or wood then your bus bar idea would work for SURE!!!!

It gives me renewed hope for a solderless/tabless battery setup.

Have you thought about using duct tape, or something else to make the batteries absolutely secure, even with the tight fit they still could pop out.



I have to look into how to build holders, maybe I can buy a 3d printer. I have to look into that, I've seen cheap ones for sale and used ones.
Expensive? It always depends, versatility and ease to reconfigure exchange cells is priceless. I did 4x 6s4p packs out of those holders to make 24s4P battery for my bike, but because I still have my lipos holding strong and no spare 400US$+ for new cutting edge 18650cells, I took old konions reversed half of the cells in every pack and use them as 3s32p in one 12V Inverter (We have some electricity problems here). Week ago, I noticed 1 group out of ballance, took group cells out, found the sucker cell and replaced it, 5 min job. :D

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 08 2015 11:35am

Exactly. 2 years from now when 18650 cells are 5000 mah and 20S for a reasonable price I can just swap out all the cells quickly and be done with it.

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 10 2015 7:41pm

It took me about 8 hours to build the basic pack. This picture shows 12 batteries in series (one in each holder), producing 43.7 volts. The ribbon of cloth is in place to help remove the batteries as they are very tight.

I took it to the garage to see how it fits on the bike and its a bit larger than the shelf but will work fine.

Image

Now I need to add the main power wires and the balance wires and build the Lexan box.

-Warren

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 14 2015 6:29pm

Added wires to the pack and removed the motor controller (ESC and wiring from my old LiPo pack. I cut out and bent up the bottom half of the polycarbonate plastic case. As shown it has room to mount the ESC and stash the wires.

Image

Here's the top cover. The jumble of wires will be hidden in one compartment of the case. The controller will be screwed to the bottom of the case and be exposed for cooling. The case is 1 1/8" thick, 13" wide and 14" deep with a notch to clear the set stays.

Image

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 17 2015 12:09pm

Over the weekend I finished the wiring for main power, charging, cell group testing and balancing. I added a switch and a fuse but could only find a 40A fuse for the holder I bought. I'll have to do some testing to see if that is adequate. I already know the system can pull up to 90A, but just for very short periods. The battery holder array, ESC, etc. are now attached the to the bottom of the plastic case.

I just need to add an LED to indicate power, load up the cells and then, test ride time!

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Re: 18650 pack build using plastic battery holders

Post by steveo » Nov 17 2015 12:42pm

looks really cool

for low current levels should work great

i like that you could take the cells out to easily replace them lol...

wish i could do that with my lipo packs lol

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Re: 18650 pack build using plastic battery holders

Post by parabellum » Nov 17 2015 12:49pm

www.recumbents.com wrote:Over the weekend I finished the wiring for main power, charging, cell group testing and balancing. I added a switch and a fuse but could only find a 40A fuse for the holder I bought. I'll have to do some testing to see if that is adequate. I already know the system can pull up to 90A, but just for very short periods. The battery holder array, ESC, etc. are now attached the to the bottom of the plastic case.

I just need to add an LED to indicate power, load up the cells and then, test ride time!
Better use 2 fuses in parallel or find other fuse holder, you do not want a failed fuse were you less expect it, in middle of nowhere. Once I had a fuse value just on the edge of its designed capability failing after half a year of use, in the worst place and moment. :)

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 17 2015 1:00pm

Yes you are right, I will order the larger fuse holder.

Oh, also I found that if I use some acid-zinc flux, my silver solder flows fine. I will need to be sure to get the solder with a flux core next time...

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Re: 18650 pack build using plastic battery holders

Post by www.recumbents.com » Nov 18 2015 4:13pm

On my previous LiPo pack I had used a loopback cable with large Anderson connectors as my on/off switch. This worked great. I thought this time I would use a large DPDT switch as a power switch for my battery pack. I added a battery in the last row of my pack which completed the circuit to the controller as apparently the switch was on. I smelled a whiff of that electronic ozone smell and immediately removed the battery. Hmm, the switch was stuck. Apparently it welded itself together. Looks like I will not not using that switch. Along with the larger fuse holder I have ordered one of those big twist switches to switch a car battery as I had good luck with that on another e-bike build. Fun.

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Re: 18650 pack build using plastic battery holders

Post by parabellum » Nov 19 2015 1:48pm

www.recumbents.com wrote:On my previous LiPo pack I had used a loopback cable with large Anderson connectors as my on/off switch. This worked great. I thought this time I would use a large DPDT switch as a power switch for my battery pack. I added a battery in the last row of my pack which completed the circuit to the controller as apparently the switch was on. I smelled a whiff of that electronic ozone smell and immediately removed the battery. Hmm, the switch was stuck. Apparently it welded itself together. Looks like I will not not using that switch. Along with the larger fuse holder I have ordered one of those big twist switches to switch a car battery as I had good luck with that on another e-bike build. Fun.
I just use regular 120V household breaker, they worked well until now and even interrupt DC over current sometimes :D (mostly the spark interrupts after lowering throttle. You hear kick, then khhhh, then after throttle down everything dies). But you can get DC breakers in same format.

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Re: 18650 pack build using plastic battery holders

Post by markz » Nov 19 2015 1:55pm

Solar stores will have DC circuit breakers. RV Parts stores as well. Those stores are everywhere now. I found a few at around $10 to about $15 then of course all the way up. I cant remember precisely what range I was looking at.

http://solarwholesaler.ca/product-categ ... -breakers/

or these fuses with hooks on them, $2 each. These are what I will use. I was thinking for my 65A controller, I will use a 100A for a battery fuse. Anything that shorts will instantly go way higher then 200A.
http://kellycontroller.com/fuses-c-34.html

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