Search found 103 matches

by Jan-Erik-86
Jan 09 2021 5:33am
Forum: E-Bike Technical
Topic: XT 90 antispark
Replies: 6
Views: 479

Re: XT 90 antispark

How fast are you plugging it in? I'm not using anti spark connectors myself, but I'm guessing the resistor wont be able to charge the caps in the controller fast enough to prevent a spark if the caps are discharged completely and you plug it in very fast. It's also possible the resistor is simply bu...
by Jan-Erik-86
Nov 28 2020 2:10pm
Forum: E-Bike Technical
Topic: Homemade Ebike battery randomly failed.
Replies: 9
Views: 297

Re: Homemade Ebike battery randomly failed.

Sounds more like your cell group was bad from the start and the bms only shut down at 68v to protect you and the battery because that group was over-discharged. In other words, it did exactly what it was supposed to. I can't explain why it smoked when you reconnected the leads though, but it seems m...
by Jan-Erik-86
Oct 30 2020 8:12am
Forum: Battery Technology
Topic: 20s x 30p pack using Vruzend V 1.6
Replies: 5
Views: 319

Re: 20s x 30p pack using Vruzend V 1.6

For that current i would use the v2.1 instead of the v1.6, as its rated for 20A per cell instead of the 3.5A rating the v1.6 have.
by Jan-Erik-86
Oct 04 2020 3:41am
Forum: Battery Technology
Topic: how do you solder without seeing?
Replies: 15
Views: 483

Re: how do you solder without seeing?

If you fear you'll be unable to hit only the positive part of the battery when welding, maybe a kit like vruzend is better for you? I've personally built my 14s8p with it and it worked really well. Sure it gets a bit larger, but it's a welding-free option, and replacing cells or reconfigureing the p...
by Jan-Erik-86
Jul 26 2020 10:40am
Forum: Battery Technology
Topic: paralleling in battery packs.
Replies: 17
Views: 831

Re: paralleling in battery packs.

1v difference is fine on a pack like that, you can probably go much higher than that also without any risks. The current flowing from one battery to another is very low as its limited by the voltage difference x battery pack resistance (including all the cables etc). Think about how much current you...
by Jan-Erik-86
Jul 16 2020 4:40am
Forum: Battery Technology
Topic: paralleling in battery packs.
Replies: 17
Views: 831

Re: paralleling in battery packs.

By different voltage, do you mean different state of charge, or different types of battery packs (like 13s vs 14s)? If only different state of charge, simply change both packs to within 1v different, then connect them together and it will work fine for both charge and discharge (assuming both have a...
by Jan-Erik-86
Jul 08 2020 2:54pm
Forum: Battery Technology
Topic: Bad charger or bad cell?
Replies: 1
Views: 110

Re: Bad charger or bad cell?

Probably just a voltage drop between the cell and the voltage meter if both meters show same voltage unloaded. Cell is likely fine if there is no excessive voltage drop when measuring directly at the cell with load.
by Jan-Erik-86
May 07 2020 4:09pm
Forum: Battery Technology
Topic: Change the BMS for a bigger one?
Replies: 19
Views: 709

Re: Change the BMS for a bigger one?

I see. Do you have a link to the battery you are considering? Although its not technically much harder to make a 100+v pack then a 12v pack, the risk involved is huge in comparison. While i would say go for it for a 24-52v pack, i wouldn't recommend that you put together a 100+v pack designed for 25...
by Jan-Erik-86
May 06 2020 1:44am
Forum: Battery Technology
Topic: Change the BMS for a bigger one?
Replies: 19
Views: 709

Re: Change the BMS for a bigger one?

I agree a new controller might be the best option if you can afford it, especially seeing that motor!

Did you find out what cells are being used in your battery pack though? Might be a good idea to make sure the battery pack can handle the extra power before buying a new controller.
by Jan-Erik-86
May 04 2020 2:58pm
Forum: Battery Technology
Topic: Change the BMS for a bigger one?
Replies: 19
Views: 709

Re: Change the BMS for a bigger one?

Those 5 bridges are the current sensing shunts, yes. It's fairly easy to add some solder to them to increase the current draw, but it's very tricky to get exactly the current you want. I don't have experience with those FETs, but with a 24x 120A FET controller it's not likely to blow up from a light...
by Jan-Erik-86
May 03 2020 12:55pm
Forum: Battery Technology
Topic: Change the BMS for a bigger one?
Replies: 19
Views: 709

Re: Change the BMS for a bigger one?

1) The easiest way to do so is buying a new kit or at least matched parts. Depends. If your controller is programmable and the FETs can handle higher current. If so, you could just reprogram it for more power. If it's not programmable, but have good FETs, you could gamble and do a shunt mod. Safest...
by Jan-Erik-86
Apr 10 2020 4:37pm
Forum: E-Bike Technical
Topic: Changing Tire Size
Replies: 2
Views: 154

Re: Changing Tire Size

Hi, and welcome!

The new tires will be a little bit smaller/thinner, but will not cause any issues. If you want, you can simply transfer your current tires to the new wheel.
by Jan-Erik-86
Mar 19 2020 6:04am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

What loads are we talking about, and what battery do you have? Individual cell voltage is looking normal to me. A smaller 13s pack at 45v could easily sag enough during high load that the controller shuts dow due to low voltage protection (often around 39v). Are you able to read the voltage right wh...
by Jan-Erik-86
Mar 05 2020 5:22am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 509
Views: 56678

Re: Li-ion cells cycle ageing

. Pretty weak cell if you ask me(mine were about 1500mah) and I just noticed they commit suicide charged under zero C* conditions ifs cell is higher than 65 m-ohm. Some studies have shows you can charge below freezing at an extremely slow charge rate, but in practice any liion cell charged normally...
by Jan-Erik-86
Jan 06 2020 5:16am
Forum: E-Bike Technical
Topic: Push Button Throttle
Replies: 19
Views: 789

Re: Push Button Throttle

Hi, and welcome to the forum! What bike or controller du you have? By push button, do you mean a simple on/off switch that switch from no power to full power, or do you want like a thumb swith where you can adjust the power? Both are usually simple to connect if your controller support a throttle, b...
by Jan-Erik-86
Dec 17 2019 7:15am
Forum: Battery Technology
Topic: Lithium battery question
Replies: 85
Views: 6620

Re: Lithium battery question

What kind of motor do you have? Normally a motor for this kind of use is a 3 phase motor, and connecting a battery directly to any of the phases will only lead to a quickly fried motor, not a spinning motor.
by Jan-Erik-86
Nov 25 2019 8:59am
Forum: E-Bike General Discussion
Topic: Winter riding and keeping battery warm
Replies: 6
Views: 1172

Re: Winter riding and keeping battery warm

I have a thin layer of insulation around my battery pack inside the hard-case, and it seems to keep the temperature quite well while in use. I tested it a couple of weeks ago when it was -9c outside. Starting temp was around +18c, and after a 35 minute ride the battery temp had only dropped around 2...
by Jan-Erik-86
Nov 20 2019 6:21am
Forum: Battery Technology
Topic: Acceptable Battery Sag
Replies: 24
Views: 2187

Re: Acceptable Battery Sag

R1112 is just the date code, meaning march 2013. The actuall modell number should also be written on it, but its not easy to read the text on Sanyo cells...
by Jan-Erik-86
Nov 20 2019 3:17am
Forum: Battery Technology
Topic: Acceptable Battery Sag
Replies: 24
Views: 2187

Re: Acceptable Battery Sag

You don't tell exactly which cell it is, but by the specs it looks like it's Sanyo UR18650A? Since these are used cells, did you test each cell for capacity, DCIR, and self discharge before putting them together? I'd charge full and check that all are at 4.2V, then discharge and check again if all c...
by Jan-Erik-86
Nov 14 2019 6:31am
Forum: Battery Technology
Topic: Acceptable Battery Sag
Replies: 24
Views: 2187

Re: Acceptable Battery Sag

I'd say 3V is normal, but it all depends on what cells you're using, what wires, what connectors, and most of all how much power you're pulling from it. As for balancing, there are basically 3 ways: 1, best) Use a programmable BMS and set it to balance at lower voltage. Also set overcharge voltage t...
by Jan-Erik-86
Nov 13 2019 3:33pm
Forum: Battery Technology
Topic: New 14s battery pack, US18650VTC6 vs NCR18650GA
Replies: 190
Views: 17210

Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Yes, but where it is only two bus bars i've made them at least double. No connections got hot during load test (constant ~2000W load over some time).
by Jan-Erik-86
Nov 13 2019 1:24pm
Forum: Battery Technology
Topic: New 14s battery pack, US18650VTC6 vs NCR18650GA
Replies: 190
Views: 17210

Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Erik possibly decided to break his Vruzend DIY into two Vruzend packs with one 4P14S up front in the frame and a 3P14S cojoined on a rack above the rear wheel? Would be helpful if Erik uploads a photo once he's satisfied with final situaton. I went with a triangular battery that fit inside the fram...
by Jan-Erik-86
Nov 10 2019 12:45pm
Forum: Battery Technology
Topic: New 14s battery pack, US18650VTC6 vs NCR18650GA
Replies: 190
Views: 17210

Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

I suppose you could, but they do not appear as common and easy to get for a 48-52V system as for a 12V system. Is there anything i'm not seeing that would make my option not work just as well with the only two disadvantages being a bit lower efficiency and an additional small box (the one i found is...
by Jan-Erik-86
Nov 09 2019 3:36pm
Forum: Battery Technology
Topic: New 14s battery pack, US18650VTC6 vs NCR18650GA
Replies: 190
Views: 17210

Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

I see some of you recommend NCR, and some say forget the GA, so i'm a bit confused.. What about NCA or is that too mild-mannered? How close are you to narrowing your choice down to your final selection? I'm not sure if i understand what you're asking? My confusion was due to people recommending NCR...
by Jan-Erik-86
Nov 09 2019 7:43am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 509
Views: 56678

Re: Li-ion cells cycle ageing

So maybe to give MJ1 the benefit of doubt and another chance need to test it again (just a suggestion). He was talking about the MG1, not MJ1. These are two very different cells and must not be mixed up. MJ1 have already been tested and turned out to be a very good cell. From what i understood, the...