Easy Ebike Battery Building Kit - Join 18650 Cells with No Welding! - Vruzend V2.1 Review


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10:14 AM
Jun 16, 2018
The VRUZEND V2.1 is a high power battery building kit. The caps are similar to the V1.5 kit, but the SS components are upgraded to copper coated with pure nickel for the highest level of conductivity and the best level of corrosion resistance. The V2.1 kit replaces the V2.0 kit by adding barrel bolts to compress the pack’s connections. This helps ensure consistent connections even under high vibration environments.

Order here:

Each V2.1 kit comes with enough components to build a battery with up to thirty-two (32) 18650 cells.

To build a battery with more than 32 cells, simply combine multiple kits together to reach any battery size you need. They also sell half size kits for your convenience.

Each basic kit includes:

  • 64 cell terminal blocks with nickel coated copper alloy spring contacts (enough for 32x 18650 cells)
Vruzend 64 cell terminal blocks.jpg

  • 64 copper-alloy screw terminals and nuts
Vruzend 64 copper-alloy screw terminals and nuts.jpg

  • 80 pure copper bus bars coated in pure nickel for corrosion resistance and high conductivity
Vruzend 80 pure copper bus bars nickel coated.jpg

  • 4 nickel-coated copper main wire clamps (for charge/discharge wires)
Vruzend 4 nickel-coated copper wire clamps.jpg

  • 8 barrel bolts for securing the pack
Vruzend 8 barrel bolts for securing the pack.jpg

The VRUZEND 2.1 kit includes all the parts necessary to join your cells together and create all of the electrical connections. However, you’ll still need a charger to charge the battery and a BMS if you you’d like to use one (recommended for safety). You’ll also need 18650 cells.

  • No soldering or spot welding required… at all! You can finally build a battery with nothing more than a socket driver or wrench and your bare hands!
  • End cap standoffs – four posts on the end of each cap keep the conductive metal components off of your workbench and help reduce the chance of short circuits. Safety first!
  • Customizable and adjustable – build a battery of any size, and increase the battery voltage or capacity as your needs change. By simply moving or adding cell blocks and series or parallel connections, you can increase the voltage or amp-hour capacity of your battery easily!
  • Serviceable – if a cell ever dies, you can open up the pack and replace it!
  • High power – The V2.1 kit is rated for 20A per cell, allowing you to power even your highest power devices!
For assembly you’ll need a 5.5 mm socket wrench or nut driver. We know that’s a bit of an odd size, and even if you have a metric set of drivers, it usually jumps from 5 mm to 6 mm. So we’ve made it easy by supplying an inexpensive 5.5 mm nut driver which you can order from our tools category

Vruzend 5.5 mm nut screw driver.jpg

We recommend that for best results, you limit the current draw of the battery pack you build with Vruzend V2.1 battery caps to approximately 20 A continuous per cell. Current bursts of up to 25 A are acceptable, but for periods not exceeding 10-15 seconds. Higher current results in more waste heat being generated which can rob your pack of performance. That means that if you build a battery with 3 cells in parallel, you should try not to exceed about 60 A continuously with that pack, though bursts of higher current are ok. Also keep in mind that if your pack is contained without air flow around the cells, you’ll want to use somewhat lower current per cell as well, as the kits are rated at 20A per cell with sufficient air flow. We believe that 20A per cell will be enough for nearly any project though, and few 18650 cells can even withstand higher current than that anyways!

Beginning with the V1.5 update, the caps have been widened very slightly to make the assembly process easier. This means that the caps aren’t as extremely tight as they were in previous generations though.
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I built my 48 Volt 13S/5P battery using this system. I greatly enjoyed making it and in practice it has worked wonderfully. The only thing I have learned is that while I have the battery encased and lying on my rear pannier I would have liked it to sit withing the triangular bike frame with the cells lying horizontally, however due to the increase of the width (from 65mm) due to the Verzund caps this is not possible. (Unless your legs are very far apart!)
Also the cell spacing adds to the overall battery dimensions.
Anyone else with comments
See pics as attached


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I have built 2 10s1p batteries with this kit. One of them recently stopped working, and I took it apart to check on it. This kit is poorly made. Caps have cracked in less than a year of use, and most of the time it’s just sitting in a storage box, and even when in use, I had it padded with foam. Out of the 20 caps on the battery, only 7 made it out unscathed (all orange caps), all the other ones became loose and came apart easily. If you look at the 2 flat head screws visible. You can see that one is bigger than the other, and the smaller one did not hold the caps together well as well is the larger one.

When putting it together though, it wasn’t bad, and it didn’t have much problems except for the smaller flathead screw, but in the long term (not even that long), thing may fall apart.

Overall not very high quality, and somewhat messy. Would not buy again.

Edit: Customer support isn't bad though, and I opened up my other battery pack. This time only 5 survived (also only orange caps)

You can see the cracks for yourself
Not reliable. Multiple failure reports. Examination of attachment methodology shows the issue.
I had the first kit about 6 or 7 years ago. The plastic melted. I do not recommend it.

I just wrap the cells with electric tape. i cut a 12" strip in half and wrap the ends then use gorilla tape and a zip tie to make cell banks 1S 8P.

Then I wire them in series. I just finished two 5S 8P 26650 LIFEPO4 packs. I am working on a third for 15S - 8P. I do not recommend 18650 lion cells. LFP is way safer for indoor charging. They will take up more space and weigh about double than lion but will have 5 to 10 times the charging cycles.

Used A123 cells are reasonable from Battery Clearinghouse.

I also bought the 8Ah Headway cells and am running a 12S 2P pack but out of 36 cells only 24 were > 5 Ah tested. However the company did send me replacements for the low capacity cells free of charge and even paid the shipping.

I hooked the 12S Headway pack in series with a 5S - 8P A123 pack and got 59V on the meter. That is 56V under load and will run on most 48V controllers. I ran it with a 1,500W 38 amp brushless controller for > 30 mph with my 1,800W brushless motor.

I have about 7 ebikes and still building them. I have a 3 kilowatt brushless motor and plan on running two 5S 8P packs in series with the 12S 2P Headway for 22S and 72V.

See my post DIY LFP packs for more information.


Curtis out.