Search found 73 matches

by kilou
Feb 25 2021 8:16am
Forum: Battery Technology
Topic: 10S4P with Samsung 29E vs 10S5P with Samsung 26H
Replies: 8
Views: 236

Re: 10S4P with Samsung 29E vs 10S5P with Samsung 26H

Who is the vendor of the unoriginal pack? I am really surprised that someone wants to sell such crappy sells at bosch prices. See here: https://www.e-bike-vision.de/product/powerpack-for-bosch-classic/en In fact the 468Wh pack has Samsung 26J cells (not 26H) but AFAIK the characteristics are the sa...
by kilou
Feb 25 2021 4:14am
Forum: Battery Technology
Topic: 10S4P with Samsung 29E vs 10S5P with Samsung 26H
Replies: 8
Views: 236

Re: 10S4P with Samsung 29E vs 10S5P with Samsung 26H

Thanks! Then I think I'll stick with the original Bosch 400Wh since I've been extremely happy with the cycle life of my pack (8 years and about 30'000km). Another advantage is that being a 4P, it is slighlty lighter than a 5P. Having more range would be great but I doubt that going from 400 to 468Wh...
by kilou
Feb 23 2021 7:46am
Forum: Battery Technology
Topic: 10S4P with Samsung 29E vs 10S5P with Samsung 26H
Replies: 8
Views: 236

10S4P with Samsung 29E vs 10S5P with Samsung 26H

Hi, I'm about to buy a new battery pack for my Bosch ebike. My ebike is 36V with a 350W nominal motor. However afaik the motor can draw up to 540W peak. Not sure whether this is exact but I guess that max amperage should always be <18A anyway. I'm considering two different packs: - 10S 4P made with ...
by kilou
Dec 24 2020 1:24pm
Forum: EBike Non-hub Motor Drives
Topic: Bosch mid drive with vesc controller
Replies: 41
Views: 10339

Re: Bosch mid drive with vesc controller

@mechhead If I understand it correctly, you use a VESC 4.12 in sensorless mode with the Bosch motor. I would be interested to know if you use sensorless BLDC mode or sensorless FOC mode and whether you experience cogging when the motor starts to assist at low RPM? I'd be interested to do the same i....
by kilou
Aug 15 2020 10:50am
Forum: Battery Technology
Topic: BMS or Hobby Charger
Replies: 7
Views: 1236

Re: BMS or Hobby Charger

Using that BMS with the charger is safer and simpler I'd say, since you don't need to mess around with the Balance plug everytime you want to charge your scooter up. Which for me can be daily. I'm also considering using a hobby charger (iCharger 3010B) instead of a BMS for a Li-ion (10S6P samsung 2...
by kilou
Jun 14 2020 8:29pm
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 790
Views: 195983

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

OK guys so i've just built a B52 Bomber battery 22S10P using LG MJ1 3500 mAh cells i've used 5mm wide 0.2mm thick solar panel bus tape - its tinned copper. scotchbrite the tops/bottoms of the cells and tinn them with solder and 80W iron, takes less than a second using fairly heavy gauge solder. Int...
by kilou
Jun 13 2020 4:33pm
Forum: Battery Technology
Topic: 18650pack cell protection idea. PTC + fuse & diode).
Replies: 25
Views: 1682

Re: 18650pack cell protection idea. PTC + fuse & diode).

In my case, the battery would be used without BMS and would be charged with a balance RC charger. Since the balance wires must be connected/disconnected on every charge, withthe balance plug sitting outside the pack, I'd have seen some potential benefits if fuses placed on the balance leads (the fus...
by kilou
Jun 12 2020 11:50pm
Forum: Battery Technology
Topic: 18650pack cell protection idea. PTC + fuse & diode).
Replies: 25
Views: 1682

Re: 18650pack cell protection idea. PTC + fuse & diode).

If you want to go that route then you need a regular fuse, never ever put passive or active parts between the bms and the cells. Sorry I don't get it. A regular fuse (i.e. non PTC) is a passive element so he cannot go that route either then. Do you mean he should only use a regular fuse after the B...
by kilou
Jun 10 2020 8:53am
Forum: Battery Technology
Topic: BOSS LEVEL CUSTOM SPOT WELDER
Replies: 471
Views: 63105

Re: BOSS LEVEL CUSTOM SPOT WELDER

Really sorry to read that, Rojitor. Take care!
by kilou
Jun 08 2020 3:48am
Forum: Battery Technology
Topic: BOSS LEVEL CUSTOM SPOT WELDER
Replies: 471
Views: 63105

Re: BOSS LEVEL CUSTOM SPOT WELDER

I did this weekend a shockproof pack for a Trampa mountainboard. My customer is more of an animal than a human so it really needs to be rock solid to last in his hands. I used both welding and the neodinium magnets technique. The welds are really really unlikely to fail due to vibrations and contin...
by kilou
Jun 03 2020 9:07am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

If your pack will end up all pretty much permanently spotwelded together, there really is not much difference, S&P connections can also happen at the same time with a laser-cut plate rather than using strips. That's what I wanted to read :) Indeed the pack will always remain in the 10S6P format...
by kilou
Jun 03 2020 9:05am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

If after riding the balance is off, takes more than 5min to correct, either get a new checker (they're cheap) or get a faster balancer. Good point! I think that's what I'll do. Anyway the balancing power is probably not going to be an issue (my RC charger can do up to 500mA to balance cells). That'...
by kilou
Jun 03 2020 7:56am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

.. unless of course you plan to “go commando” with no BMS ? :o In fact this is what I plan to do: no BMS but charging using a hobby balance charger (incl. temperature sensor) + use 2 lipo checkers as low voltage alarms, as suggested by Shawn McCarty in this video. https://www.youtube.com/watch?v=pl...
by kilou
Jun 03 2020 6:50am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

Thanks for your reply dogman dan. I think there may be some misunderstanding about what I intend to do. I understand that building series first effectively means building 6 10S1P batteries. But if all the individual cells (from all these 6 batteries) have exactly the same voltage, I don't get why it...
by kilou
Jun 02 2020 12:21pm
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

I think I'll end up using M2 bolts and nylok nut instead of solder to secure the tabs between cells. The connections would look like this (I may still add a washer below the nylok nut): https://i.imgur.com/DhFBqbm.png Keeping everything Nickel plated should avoid any corrosion issue. The series conn...
by kilou
May 28 2020 1:23am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

:shock: What you have shown is impossible to assemble with any voltage in the cells, and would burst into flames if you tried to charge it ! If you Do not understand the problem here, ..or the point about the BMS requirements, then i urge you not to attempt to assemble a battery until you have rese...
by kilou
May 28 2020 1:21am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

A common pack build might use a style of nickel bus that is shaped like a ladder, and it accomplishes the series and parallel connections at the same time with a single layer of nickel sheet. I'm thinking about building a DIY 10S6P battery pack using new Samsung 29E cells bought with Z-solder tabs ...
by kilou
May 28 2020 12:59am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

I was thinking about a situation like this, considering for example a 10S3P battery. https://i.imgur.com/7CuwxDQ.png Suppose that I have 30 cells each with a capacity of 1C and I start by making the 3 series strings (grey connections) and then start with the first parallel connection (blue). At this...
by kilou
May 27 2020 2:59pm
Forum: Battery Technology
Topic: Any lipo checker that is not powered only from first cell?
Replies: 17
Views: 523

Re: Any lipo checker that is not powered only from first cell?

For one hour, it would only draw 50MaHr of pack capacity. For a 10AH pack, it would take 200 hours to deplete pack (10,000Mahr/50MaHr = 200). For a one hour ride, you would use about 1/2 percent of pack. Is it possible to calculate the voltage difference that would result between the first cell (po...
by kilou
May 27 2020 2:18pm
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

Re: DIY Li-ion battery: first connect cells in series, then in parallel

I do not grok at all what you are saying about different capacities while building - I think you are imagining something there that is not the case. All cells should be at exactly the same SoC/voltage, capacity/SoH etc before you start. IMO do not bother with scrap cells. My wording was probably in...
by kilou
May 27 2020 11:19am
Forum: Battery Technology
Topic: DIY Li-ion battery: first connect cells in series, then in parallel
Replies: 22
Views: 886

DIY Li-ion battery: first connect cells in series, then in parallel

Hi, when building a Li-ion battery, it seems usual to first build groups of parallel cells and then connect these in series. Is it actually safe to do it conversely: first build groups of cells in series and then connect these groups in parallel? I understand that groups of cells connected in series...
by kilou
May 25 2020 3:17am
Forum: Battery Technology
Topic: Any lipo checker that is not powered only from first cell?
Replies: 17
Views: 523

Re: Any lipo checker that is not powered only from first cell?

Put a switch on first input wire to lipo checker.....just turn it off when not in use and it does not draw current. A switch wouldn't really help in my application because I'd like to use it while riding so that it monitors the voltage continuously and beeps if one cell gets too low, in replacement...
by kilou
May 25 2020 3:06am
Forum: Battery Technology
Topic: (semi)-solderless design: Attaching cells with solder tags using brass bolts
Replies: 16
Views: 579

Re: (semi)-solderless design: Attaching cells with solder tags using brass bolts

After reconsidering @Hillhater suggestions, I may also consider soldering the U tabs on the copper bus bars instead of using brass bolts but this is still to be decided. Anyway, here are a few picture of the layout for a 10S6P battery: top view: https://i.imgur.com/r40b5UB.png bottom view: https://i...
by kilou
May 22 2020 11:29am
Forum: Battery Technology
Topic: (semi)-solderless design: Attaching cells with solder tags using brass bolts
Replies: 16
Views: 579

Re: (semi)-solderless design: Attaching cells with solder tags using brass bolts

...50-100+ Multiples of unproven small bolted connections, lies in the increased probability of a bad contact, loose nut, corrosion, etc. Reliability is improved by keeping things simple with temporary connections and part count at a minimum A spot-welded or soldered connection can also fail, espec...
by kilou
May 22 2020 11:15am
Forum: Battery Technology
Topic: Any lipo checker that is not powered only from first cell?
Replies: 17
Views: 523

Re: Any lipo checker that is not powered only from first cell?

amberwolf wrote:
May 21 2020 6:04pm
They don't all--many do but you must check that the one you want to use does so.
Ok thanks for the information, I did not know that. Or would it be possible to mod a lipo checker so that it draws power from an external source rather than the one being tested?