Kit ordered the 20th, the post office tried to deliver yesterday (my nice neighbours sold their bar so no one to take delivery). I will pick it up today.
Diy solderless 18650 battery kit.
- Thread starter Nealh
- Start date
Technical question: how many bus bars for a serial connection?
My battery has a triangular end and it is going to be hard to have more than two bus bars in series. Everywhere else there are three bars. I am at work so no pic before tomorrow afternoon.
My battery has a triangular end and it is going to be hard to have more than two bus bars in series. Everywhere else there are three bars. I am at work so no pic before tomorrow afternoon.
On the ES thread page 10 Micah Toll has shown a diagram for your scenario and seems to have doubled up on one of buss bar connections..
Before connecting any buss bars in P double check your continuity voltage for each cell . Having put my 5p 10s pack together tonight on rechecking, 3 cells had no voltage even after mallet and block and a cramp. I had to part disassemble to pull out the cap spring connection.
One thing I didn't try before disassembly was to put a nut on the offending bolt thread to see if any of the three needed pulling up yo make the contact.
One thing I didn't try before disassembly was to put a nut on the offending bolt thread to see if any of the three needed pulling up yo make the contact.
Last edited:
Ta much! Same strategy I was going to use. I have a group of 4 cells at the pointy end in a 2x2 square. I will test with the tired cells and the SS bus bars things will be easier with the nickel connectors.
Yeah I noticed that some of the springs are slightly depressed so will pull all the caps up before inserting the cells. Thanks for the heads up!
When I pull a pack apart I find the battery contacts all most pushed together,not much spring action. Don't know how many times you would be able to pull up on the contacts before they would snap. Instead of cable ties round the pack I decided to drill the holders and bolt them together.
Someone on ES and Vruzend said this would not be advisable on a large pack and I would be better off sandwiching the pack between two pieces of wood/plastic,then bolting it together.This would really squash the contacts this makes me question the need for them.And makes me think could they be replaced by brass bolts.
I can't use the sandwich idea I don't have enough room in my battery box. 5s battery won't fit in my box.
Had to get the grinder out and shave a bit off the packs.
They fit OK now.
Made some end caps from ice cream tubs.
Going to order another kit. My battery box holds two lawn mower batteries 40 cells I can fit 60 cells in it with the Vruzend holders.
I can't use the sandwich idea I don't have enough room in my battery box. 5s battery won't fit in my box.
I like your brass bolt idea, better conductivity than nickel. Surely there are brass springs around?
I used a nut to pull a bolt up on a cell (10s pack) with no voltage it did the trick, contact made and 3.55v registered which is how they arrived from Nkon.
10s pack built and buss bars bolted on and BMS to wire up next , waiting for a new iron as I broke/shorted my existing one
.
Pleased with the 7s pack built, recharged it tonight bang on 29.4v via the BMS I soldered.
10s pack built and buss bars bolted on and BMS to wire up next , waiting for a new iron as I broke/shorted my existing one
.Pleased with the 7s pack built, recharged it tonight bang on 29.4v via the BMS I soldered
.
D
Deleted member 4366
Guest
this is beginning to look terribly Heath Robinson-ish,
whats the weight and size when finished compared to a similar aH Case battery?
how are you going to protect it from the elements?
what if you want to mount it to the frame, how can you do that?
can you disconnect it easy enough from the bike to charge etc?
whats the weight and size when finished compared to a similar aH Case battery?
how are you going to protect it from the elements?
what if you want to mount it to the frame, how can you do that?
can you disconnect it easy enough from the bike to charge etc?
Some of us have complicated frames...
1. Slightly larger about the same weight
2. In a bespoke battery box
3. Screwed to the bottle holder rivnuts like a commercial battery
4. Yes, the battery box will have a door that locks but most charging will be done on the bike because I can...
1. Slightly larger about the same weight
2. In a bespoke battery box
3. Screwed to the bottle holder rivnuts like a commercial battery
4. Yes, the battery box will have a door that locks but most charging will be done on the bike because I can...
Sounds a bit heath however my finished shrink wrapped 100a 7s pack looks pretty much as neat as the one Jimmy made for me, just a different way of engineering the battery.
Pretty easy to pull apart in the future, no welded tabs to break or re-weld. Design a build to suit your own needs and requirements, large or small pack for long range or light pack for short local riding. Choose any cell you want use even reclaimed cells from 3rd party usage, good if you can get them for free or very very cheaply.
See Doc Bass on ES and the 100's/1000's of good cells he reclaims for free from Bosch tool packs from Bosch centres in Canada.
Go watch the Vruzend video on the links in this thread.
My house wring won't support a welder at 60 amps plus so a simple diy pack build is welcome, great knowledge and know how to how a pack is built and works. Valuable insight in to knowing how to assemble and fault diagnose a pack and how bms is actually wired up.
A bespoke frame housing/hard case for a frame mounted battery could be made, for me my shrink wrapped battery with foam outer covering will be carried in panniers.
My 10s 5p 14.5ah/50a pack 6lbs 4oz, size is 220mm L x 110mm W x 89mm H with bms to add and shrink wrap.
14,5ah dolphin 6lbs 12oz 315mm L x 85mm H x 125mm W.
No harder to remove then a hard case pack, charging no different whether on or off bike.
I'm still like I was when a kid, I like building stuff. A bit old for wooden go-carts Lego, airfix but a bit of battery tech I find is good and easy peasy once you understand it. And now can easily afford it, it would easier to go to Jimmy or get a ready made pack but no where near the knowledge base or pleasure of building a simple pack.
Pretty easy to pull apart in the future, no welded tabs to break or re-weld. Design a build to suit your own needs and requirements, large or small pack for long range or light pack for short local riding. Choose any cell you want use even reclaimed cells from 3rd party usage, good if you can get them for free or very very cheaply.
See Doc Bass on ES and the 100's/1000's of good cells he reclaims for free from Bosch tool packs from Bosch centres in Canada.
Go watch the Vruzend video on the links in this thread.
My house wring won't support a welder at 60 amps plus so a simple diy pack build is welcome, great knowledge and know how to how a pack is built and works. Valuable insight in to knowing how to assemble and fault diagnose a pack and how bms is actually wired up.
A bespoke frame housing/hard case for a frame mounted battery could be made, for me my shrink wrapped battery with foam outer covering will be carried in panniers.
My 10s 5p 14.5ah/50a pack 6lbs 4oz, size is 220mm L x 110mm W x 89mm H with bms to add and shrink wrap.
14,5ah dolphin 6lbs 12oz 315mm L x 85mm H x 125mm W.
No harder to remove then a hard case pack, charging no different whether on or off bike.
I'm still like I was when a kid, I like building stuff. A bit old for wooden go-carts Lego, airfix but a bit of battery tech I find is good and easy peasy once you understand it. And now can easily afford it, it would easier to go to Jimmy or get a ready made pack but no where near the knowledge base or pleasure of building a simple pack.
Last edited:
I have now finished the second battery a 5p10s 50a using 2900mah PF cells.
Wasn't impressed with the BMS as after the first charge balancing was woeful, 2 P strings had 4.18v and the rest about 3.86 - 3.92 average battery voltage was 39.8v. A bit of manual discharging and charging to get the cells even and another charge was given, managed to get pack voltage of 40.6v and again cell balancing was still poor.
Not trusting this BMS I swapped it out for a different smaller one with and old fashioned shunt and got a 41v average charge with a bit better cell balancing, so decided on a 40 mile discharge run along the Worth way to Groombridge and back on Tuesday evening. Paralleled it with my 13ah Oxydrive batt and measured 38.7v on return, the following day I checked the cell discharge balance and had a 0.6 v variation. Placed on charge and left today and battery is looking much better now voltage has finished at 41.9v and balance looking good may check P strings with DVM tomorrow but generally all looking a lot better now.
I have two spare chargers and found on both the output voltage on the high side not having any adjustment have decided to get a 42v enclosed HLG 100 Meanwell adjustable supply.
.
Wasn't impressed with the BMS as after the first charge balancing was woeful, 2 P strings had 4.18v and the rest about 3.86 - 3.92 average battery voltage was 39.8v. A bit of manual discharging and charging to get the cells even and another charge was given, managed to get pack voltage of 40.6v and again cell balancing was still poor.
Not trusting this BMS I swapped it out for a different smaller one with and old fashioned shunt and got a 41v average charge with a bit better cell balancing, so decided on a 40 mile discharge run along the Worth way to Groombridge and back on Tuesday evening. Paralleled it with my 13ah Oxydrive batt and measured 38.7v on return, the following day I checked the cell discharge balance and had a 0.6 v variation. Placed on charge and left today and battery is looking much better now voltage has finished at 41.9v and balance looking good may check P strings with DVM tomorrow but generally all looking a lot better now.
I have two spare chargers and found on both the output voltage on the high side not having any adjustment have decided to get a 42v enclosed HLG 100 Meanwell adjustable supply.
.
15 more HE2's arrived today so with 30 caps left over a 5P 3S 100a pack is going to be built, give me the option of putting it in series with the 100a 7s pack for my 36v bikes.
I still have another box/kit in the garage so one for the future.
The upgraded kits should be under development by now with nickel plated copper fittings.
I still have another box/kit in the garage so one for the future.
The upgraded kits should be under development by now with nickel plated copper fittings.
When I ordered some equipment from India a few years ago now, I got hit heavily with customs duty and even the courier charging me a high fee to collect the customs fees. If I recall, the value of the goods charged for import duties and customs charges incorporated the hefty carriage charges as well.
However, a question if the more techie amongst us can answer. When I disassembled an old lithium ebike battery a few weeks ago there was some complicated looking electronic battery management circuitry inside together with wires running here and there.
Are these lithium kit batteries simply charged as we usually charge a lead/acid type battery? That is, just stick the charger onto the pos and neg leads of the battery, observing polarity and, of course, using a dedicated lithium battery charger?
Also, has anyone discovered a supplier for the 18650 cells to make these batteries up from a cheap source? If I was to make one up then I would need 40 cells for my 36v system.
On the face of it, the biggest advantage of these DIY kits would enable us to service our batteries, ability to change single duff cells when required, etc. etc.. When I stripped my old battery the cells were spot welded to the bus-bars and virtually had to rip them apart.
Joseph
D
Deleted member 4366
Guest
You need to install a BMS to manage the battery. That's the circuit board and wires that you mentioned. Charging is simple if you have installed the BMS.
Thank you, it does make sense to me to install BMS. I notice there are dozens from China on eBay but wondered if I should look out for a branded product, if indeed there is such a thing?
I have to say, I'm fascinated with the idea of making my own battery, just for the hell of it but reading one or two posts here, some have been copped for customs etc., on top of all the rest of the outlays and doing some sums, I wonder if a project would be cost effective? To put it into perspective, I bought, a short time ago, a 15.6 AH battery for £227 and comes in a nice shiny can, all sealed and ready to go and rail to fit to the bike to make the installation, with a battery status suite of LEDs, a rear light, an ignition switch, a charging socket and a couple of power leads to the controller with bullet connectors and not forgetting the purpose matched battery charger.
Having said that, I do admire the pioneers who have posted their efforts and top marks to skill and enthusiasm.
Joseph
D
Deleted member 4366
Guest
If you want to practice, I have a load of cells you can have. they're from faulty e-bike batteries, but most of the cells are OK.
I was charged VAT because the value was over the £39 chargeable threshold, I should have checked the HRMC site first .
Nkon is really the only place for new cells at reasonable a price and no extra scrutiny from HMRC etc.
Cells from China are a lot cheaper but with postage they aren't then there is the chance you will be charged VAT and import duty.
.Nkon is really the only place for new cells at reasonable a price and no extra scrutiny from HMRC etc.
Cells from China are a lot cheaper but with postage they aren't then there is the chance you will be charged VAT and import duty.