Search found 279 matches

by thepronghorn
Nov 28 2020 3:10am
Forum: Battery Technology
Topic: Daisy chain active balancer
Replies: 7
Views: 179

Re: Daisy chain active balancer

If there is more than 0.1v difference between the parallel cell group the board will transfer the highest parallel group voltage to the lowest parallel group until every parallel cell group is equalized. The tolerance is 0.03v, which is very good. I know what an active balance board is suppose to d...
by thepronghorn
Nov 17 2020 9:20pm
Forum: Motor Technology
Topic: Efficiency of stator oriented control
Replies: 11
Views: 356

Re: Efficiency of stator oriented control

I think you should clarify that this is what you mean before going around posting that you "think energy recover hardly justifies regen" That is also my opinion generally, not just for my use cases. I was answering your question as to what I meant by "personally". If measured ac...
by thepronghorn
Nov 17 2020 6:39pm
Forum: Motor Technology
Topic: Efficiency of stator oriented control
Replies: 11
Views: 356

Re: Efficiency of stator oriented control

I choose low maintenance for my own bikes, meaning direct drive hub motors without regen. So I sacrifice a little efficiency on both counts, in favor of reliability. How do you figure regen to negatively affect reliability of a system? Reversing reaction torque at the axle tends to loosen threaded ...
by thepronghorn
Nov 16 2020 3:20pm
Forum: Motor Technology
Topic: Need help : number of pole pairs
Replies: 5
Views: 520

Re: Need help : number of pole pairs

Easy way to find out number of coils in electric motor is to connect classic voltmeter to its power lines and slowly turn wheel by 360 degrees counting numbers of movement of the needle (pointer). Just verified that way my 205 50H V3 QS Motor, has 16 coils. Voltmeter was set to 3V DC... Hi Maciek, ...
by thepronghorn
Nov 16 2020 3:16pm
Forum: Motor Technology
Topic: Efficiency of stator oriented control
Replies: 11
Views: 356

Re: Efficiency of stator oriented control

Not sure what you mean by "personally," but there are definitely routes where it is possible to recover significant amounts of energy from regen... There are more situations where regen isn't worth the energy lost by not having freewheeling. Most people live in areas that became populated...
by thepronghorn
Nov 16 2020 3:14pm
Forum: Motor Technology
Topic: Efficiency of stator oriented control
Replies: 11
Views: 356

Re: Efficiency of stator oriented control

Personally I think the energy recovery hardly justifies regen Not sure what you mean by "personally," but there are definitely routes where it is possible to recover significant amounts of energy from regen... I mean wrt my own decision-making, prioritizing among the myriad factors. I set...
by thepronghorn
Nov 14 2020 3:57am
Forum: Motor Technology
Topic: Efficiency of stator oriented control
Replies: 11
Views: 356

Re: Efficiency of stator oriented control

Personally I think the energy recovery hardly justifies regen. It's all about more efficient / effective braking, greater control on long descents with heavy loads afaic. With saving brake pad wear in between. Not sure what you mean by "personally," but there are definitely routes where i...
by thepronghorn
Nov 04 2020 12:30am
Forum: Battery Technology
Topic: Parallel balancing 20S12P battery
Replies: 15
Views: 392

Re: Parallel balancing 20S12P battery

You CANNOT do this unless you disconnect the series connections between the 4S subpacks. Otherwise you will SHORT CIRCUIT the packs. Also the imax B6 at 50W max is going to take ~50 hours to charge a 20S12P battery assuming each cell is ~10Wh.
by thepronghorn
Nov 03 2020 5:25pm
Forum: Battery Technology
Topic: bluetooth BMS?
Replies: 1609
Views: 204944

Re: bluetooth BMS?

I know that the cell counts are configurable in the PC software, but can they be set below the range that they are advertised as being capable of handling? For example, if I buy the 15S version of the 10S-15S BMS linked below, can I configure the BMS to work properly on 8S? I am running 8S right no...
by thepronghorn
Nov 03 2020 3:15pm
Forum: Battery Technology
Topic: bluetooth BMS?
Replies: 1609
Views: 204944

Re: bluetooth BMS?

I know that the cell counts are configurable in the PC software, but can they be set below the range that they are advertised as being capable of handling? For example, if I buy the 15S version of the 10S-15S BMS linked below, can I configure the BMS to work properly on 8S? I am running 8S right now...
by thepronghorn
Nov 03 2020 2:19pm
Forum: Items for Sale - New
Topic: N.E.S.E. the no solder module
Replies: 427
Views: 67344

Re: N.E.S.E. the no solder module

The link in his signature works for me (albeit slowly). I think PLA can work, but PETG/ABS/PC are much preferred due to their higher temperature handling capabilities. Thats weird. I moved my site to bluehost which is in US so americans would have faster service, gues its not that great I think it'...
by thepronghorn
Nov 02 2020 3:30pm
Forum: Battery Technology
Topic: Single 20S9P with 12v step down or 20S9P with 4S2P
Replies: 10
Views: 226

Re: Single 20S9P with 12v step down or 20S9P with 4S2P

How do you turn on your bike? Sometimes a standalone 12V battery is needed to power the coil on the contactor of the main battery. This is standard for large electric vehicles that are running 300V+ main battery packs. For a 20S battery, you may be electing to forgo a contactor in which case you co...
by thepronghorn
Nov 02 2020 4:18am
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

Thinking some more about what pronghorn wrote (among others), and wondering: thepronghorn wrote: ↑20 Oct 2020, 22:46 I'm not saying the per cell charge current decreases, just saying the total pack charge current decreases. 4P at 10A is 2.5A/cell, so a 2P pack would only be able to do 5A total. to ...
by thepronghorn
Nov 02 2020 4:00am
Forum: Items for Sale - New
Topic: N.E.S.E. the no solder module
Replies: 427
Views: 67344

Re: N.E.S.E. the no solder module

The link in his signature works for me (albeit slowly). I think PLA can work, but PETG/ABS/PC are much preferred due to their higher temperature handling capabilities.
by thepronghorn
Nov 02 2020 3:54am
Forum: Battery Technology
Topic: Single 20S9P with 12v step down or 20S9P with 4S2P
Replies: 10
Views: 226

Re: Single 20S9P with 12v step down or 20S9P with 4S2P

How do you turn on your bike? Sometimes a standalone 12V battery is needed to power the coil on the contactor of the main battery. This is standard for large electric vehicles that are running 300V+ main battery packs. For a 20S battery, you may be electing to forgo a contactor in which case you cou...
by thepronghorn
Oct 27 2020 4:43pm
Forum: Battery Technology
Topic: 10w solar panel connected to lead acid battery
Replies: 10
Views: 346

Re: 10w solar panel connected to lead acid battery

This sounds like one of those trickle chargers that people leave on car batteries that they don't drive very often. I think it will work. You'll want to make sure the open circuit voltage of the 12V nominal panel minus the diode voltage drop matches the float charge voltage of the battery (normally ...
by thepronghorn
Oct 27 2020 4:33pm
Forum: Battery Technology
Topic: Battery Design advice sought
Replies: 14
Views: 633

Re: Battery Design advice sought

Looks like a nice, well thought out layout. I think the area you need to focus on is the row to row connections. Everything else seems pretty standard. You've written "bend or side bus bar". I don't really like the bend - you'll have to do the welds first then bend it and it seems like it ...
by thepronghorn
Oct 21 2020 3:44am
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

I'm not saying the per cell charge current decreases, just saying the total pack charge current decreases. 4P at 10A is 2.5A/cell, so a 2P pack would only be able to do 5A total. Sure - but 5A at 72V, vs 10A at 36V, isn't it? = 360W. The actual voltage from the hub is something else, transformed by...
by thepronghorn
Oct 20 2020 9:46pm
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

.... querkus wrote, In my experience adding more P cells works better than a longer serie. Reason for that is that internal resistance of cells is greater than properly sized nickel/copper between cells. My reply: if this is true, then my plan to go to higher voltage is doomed. Is this also why the...
by thepronghorn
Oct 20 2020 9:35pm
Forum: E-Bike Non-hub Motor Drives
Topic: Calibrating The Torque Sensor On A TSDZ2 in simple English
Replies: 3
Views: 327

Re: Calibrating The Torque Sensor On A TSDZ2 in simple English

The procedure doesn't look too hard to do. Which part do you not understand?

Basically you're just putting several different weights on the pedals and recording the weights and measured torque values to calibrate the sensitivity of your sensor.
by thepronghorn
Oct 19 2020 7:56pm
Forum: E-Bike Non-hub Motor Drives
Topic: Calibrating The Torque Sensor On A TSDZ2 in simple English
Replies: 3
Views: 327

Re: Calibrating The Torque Sensor On A TSDZ2 in simple English

It might help if you posted the github link you need translated.
by thepronghorn
Oct 12 2020 4:04am
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

I think you have an error in your voltage calculations. 42V for a 10S battery is 4.2V/cell. 54.6V for a 14S battery is 3.9V/cell. If you redo your math with the correct voltages, you'll find that the charge power is exactly the same no matter which way you configure the cells. Correct - thanks for ...
by thepronghorn
Oct 12 2020 3:10am
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

Do you have experimental data to support this ? In my experience adding more P cells works better than a longer serie Sure, but I think you're talking about something else. The original was, I think, about available regenerative braking force given a 10A charge limit. If you can put in only 10A at ...
by thepronghorn
Oct 12 2020 3:06am
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

Hi again. Pronghorn, that is a very interesting statement, and begs questions about definitions. You said: ... there is going to be a certain limit on the charge rate which limits the regen power. If you want more regen power, you need more cells. [/i] Is that true? The charge rate would be the cur...
by thepronghorn
Oct 08 2020 6:34pm
Forum: E-Bike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 1736

Re: raising voltage to maximize regen. braking?

For a given battery cell, there is going to be a certain limit on the charge rate which limits the regen power. If you want more regen power, you need more cells. Whether you arrange the cells in series for higher voltage or parallel for higher current doesn't matter from the battery's point of view...