Search found 159 matches

by obcd
Feb 18 2020 8:03am
Forum: Battery Technology
Topic: Lithium battery question
Replies: 85
Views: 6691

Re: Lithium battery question

A 20 Amps BMS will limit the current to 20 Amps. It usually does this by switching off the battery output voltage when there is 2 much current asked. Sometimes you need to connect a charger to the battery to bring a BMS that went into current protection back to life. So, you don't want it to go into...
by obcd
Feb 17 2020 10:36am
Forum: EV Business World
Topic: EV charging prices in Europe increase 500%
Replies: 29
Views: 4412

Re: EV charging prices in Europe increase 500%

Our gouvernment stopped giving a fee to individuals who bought an EV. They claimed it wasn't used much anyhow. Companies are able to add such a car to their expenses for 120% the first 2 years and for 100% a couple more years. My boss drives electric, and it's surely not because he's worried about t...
by obcd
Feb 17 2020 9:14am
Forum: EV Business World
Topic: EV charging prices in Europe increase 500%
Replies: 29
Views: 4412

Re: EV charging prices in Europe increase 500%

Most EV's are bought by companies. They are simply charged at the company during daytime. So the charging stations are not used enough to pay off for their investment. Solution: increase the price for a charge. People still using the charging station have no alternative as they clearly need some cha...
by obcd
Feb 17 2020 8:14am
Forum: Battery Technology
Topic: Fast Charging - What is the secret?
Replies: 36
Views: 2548

Re: Fast Charging - What is the secret?

The first e-bikes using super capacitors as energy storage start to appear on the market. They can't beat lithium considering energy density, but it's sure something to keep an eye on. Those super capacitors can also charge very fast. I wouldn't be suprised if we will see hybrid batteries in the fut...
by obcd
Feb 17 2020 8:04am
Forum: Battery Technology
Topic: Lithium battery question
Replies: 85
Views: 6691

Re: Lithium battery question

Are you sure your cells can handle a 30 Amps discharge rate.
I seem to remember it's a 4P which means only 4 cells in parallel.
Assuming the cells are 2500mAh. If you pull 20A they will be empty after a 30 min. ride.
by obcd
Feb 17 2020 7:54am
Forum: Battery Technology
Topic: Bosch powertube repair
Replies: 6
Views: 1113

Re: Bosch powertube repair

Bosch doesn't like it if you mess with their batteries. If you disconnect the cells from the bms or even disconnect one of the balance wires, the bms "shuts off" and refuses to restart afterwards. It needs some factory hocus pocus to come back to live. I have no idea if your packs are like...
by obcd
Feb 14 2020 6:22pm
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

Are you sure you can reflash the 850C with a CH340 based usb2ttl serial adapter? I was under the impression the flashing software only supported adapters with the CP2102 chipset. Besides appearing as a comport, some windows drivers have a "low level" way to access the usb2 serial bridge ch...
by obcd
Feb 13 2020 5:32pm
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

They are not hugely overpriced as they only use quality cells and quality bluetooth bms boards. (At least that's what they claim to do) Do you want to pay a little more or constantly live with the fear they might set your house on fire one day? The battery still is the most expensive and important p...
by obcd
Feb 13 2020 11:35am
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

60V and 16A makes 960W and will melt your motor unless you have a temperature sensor installed that automatically reduces the motor current.
by obcd
Feb 08 2020 6:29pm
Forum: Battery Technology
Topic: 4.1V 4s2p - bms with adjustable top and bottom cutoff
Replies: 29
Views: 3020

Re: 4.1V 4s2p - bms with adjustable top and bottom cutoff

A BMS should not only protect a battery against over charging, but also against over discharging. Finally, it should also protect the battery against over current. And, there are balancing BMS and non balancing BMS. IMHO, a bluetooth BMS is worth it's money as it allows to inspect the voltage of eve...
by obcd
Feb 08 2020 8:15am
Forum: Motor Technology
Topic: Tsdz2 firmware open source adapted to vlcd5, vlcd6 and xh18
Replies: 1554
Views: 174918

Re: Tsdz2 firmware open source adapted to vlcd5, vlcd6 and xh18

The open source firmware uses "simplified FOC" to drive the motor. That should be more efficient than the standard firmware. The open source firmware has options to adjust maximum battery current and motor winding currents. This allows the motor to produce higher peak power when needed if ...
by obcd
Feb 03 2020 1:52pm
Forum: Battery Technology
Topic: Ebike battery charger
Replies: 22
Views: 993

Re: Ebike battery charger

I assume you try to avoid a BMS with this method. Let's not forget that a BMS also disconnects the battery if one of the cell group it's voltage becomes lower than the allowed treshold. Discharging lithium cells 2 much will damage them and will increase the risk of catching fire when you recharge th...
by obcd
Feb 03 2020 4:22am
Forum: Motor Technology
Topic: Bafang SW102 Bluetooth LCD - OpenSource firmware and mobile app
Replies: 433
Views: 64930

Re: Bafang SW102 Bluetooth LCD - OpenSource firmware and mobile app

I have no experience, but don't you have to press f instead of t for flashing?
by obcd
Jan 29 2020 1:03pm
Forum: E-Vehicles General Discussion
Topic: Get bucked by shorting old hub motor?
Replies: 23
Views: 2669

Re: Get bucked by shorting old hub motor?

A single phase short will work as a serious regenerative brake as the voltage generated in that phase will be shorted with only the wire resistance as current limiting factor. A motor with internal gearing that allows freewheeling is indeed the safest way to prevent injuries. I have seen a hub motor...
by obcd
Jan 29 2020 12:47pm
Forum: Motor Technology
Topic: Motor internal temp?
Replies: 5
Views: 462

Re: Motor internal temp?

I can't speak for inductance, but the magnetic strength of the magnets decreases at higher temperature. No idea if it's a temporary issue or a permanent issue that only happens above a certain temperature treshold.
by obcd
Jan 29 2020 5:38am
Forum: Battery Technology
Topic: Help pls - New battery Unbalanced after 3 cycles
Replies: 7
Views: 702

Re: Help pls - New battery Unbalanced after 3 cycles

Some of the cells of that high voltage group not being connected or being bad is the most likely cause of what you see. Discharging the cell group with the 5V lamp is a good idea, but you should monitor that cell group voltage all the time. After discharge, measure the voltage of each individual cel...
by obcd
Jan 29 2020 5:22am
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

Well, yes, display pinout and motor pinout should match, but the 850C is a display for bafang mid drive motors and you are using it on a TSDZ2 motor.
So originally, it's not just plug and play. If it worked before with the TSDZ2 motor, wiring should match.
by obcd
Jan 29 2020 3:38am
Forum: Battery Technology
Topic: Using cheap adjustable power supply to get 80% charge?
Replies: 29
Views: 2493

Re: Using cheap adjustable power supply to get 80% charge?

I was just explaining how a good lithium battery charger is suposed to work. If you charge lithium batteries for 100% every time, you will reduce battery life doing so. If you only charge up to 80%, battery life can be 2 - 3 times higher. In your case, the batteries will never reach the voltage you ...
by obcd
Jan 27 2020 3:42pm
Forum: Battery Technology
Topic: can't increase current when charging (boost inverter)
Replies: 5
Views: 582

Re: can't increase current when charging (boost inverter)

Pc power supplies don't like it if the 5V and 3V3 rails aren't loaded.
They also usually deliver more current on that 5V and 3V3 volt rail.
Some ATX supplies don't even start up if they aren't properly loaded. Maybe those server supplies are different?
by obcd
Jan 27 2020 3:34pm
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

Multimeters set to voltage have a very high input resistance. So measuring between +Vin and TxD shouldn't cause a problem. You should be able to find the gnd wire by disconnecting your battery and waiting several minutes. next, measure the voltage between the battery minus connection (motor side) an...
by obcd
Jan 25 2020 8:04am
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

How well is the SW102 readable in direct sunlight? I also like the idea of having a minimalistic cheap display that doesn't attract thiefs. The setup and advanced stuff could eventually be done with a smartphone using the bluetooth interface. In such case you have something simple for those who like...
by obcd
Jan 25 2020 7:55am
Forum: Battery Technology
Topic: Using cheap adjustable power supply to get 80% charge?
Replies: 29
Views: 2493

Re: Using cheap adjustable power supply to get 80% charge?

The power supply also has a current control, so you can limit current. If you set the voltage to the maximum you want to go, you can set the current to the amount you want the batteries to charge. So, basically, it will work equal to a CC/CV charger. Good chargers will keep charging, even when the m...
by obcd
Jan 24 2020 10:03am
Forum: Battery Technology
Topic: Using cheap adjustable power supply to get 80% charge?
Replies: 29
Views: 2493

Re: Using cheap adjustable power supply to get 80% charge?

If someone accidently turns up the voltage or sets it wrong, you can overcharge your batteries.
A good BMS should be able to prevent this. Otherwise, it should work fine, but I would never use it without a BMS.
by obcd
Jan 24 2020 9:49am
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

Is there a way to keep the SW102 in it's bootloader so that a new firmware can be uploaded over bluetooth, so that it can be flashed without opening it? I know geeksville was working on that, but still had an issue that jumping from firmware back to (original) bootloader didn't work as it didn't ena...
by obcd
Jan 22 2020 5:37am
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 6507
Views: 481875

Re: TSDZ2 mid drive and 850C and SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

The whole point of the calibration is to allow the assists levels to give motor power proportional to your own power. So, after calibration, it will likely give less assistance on assist level 1 and that assistance should increase when you increase your assist level. It will work like that till it r...