Search found 176 matches

by vex_zg
Jan 30, 2018 7:17 pm
Forum: Battery Technology
Topic: Lipo fire - Accidentally charged 14S with BMS @ 84V - should BMS have prevented this?
Replies: 22
Views: 799

Re: Lipo fire - Accidentally charged 14S with BMS @ 84V - should BMS have prevented this?

I've tested my Besttech BMS and it allowed my pack to go overvoltage, to 4.25-4.3V per cell (this was for a short while, I ended this manually and I don't know when it would have stopped) I can't tell exactly why but the BMS might be counting on bleeding resistors to relieve some voltage (which they...
by vex_zg
Jan 14, 2018 10:45 am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 164
Views: 16419

Re: Spot Welding Copper Strips to 18650 Battery Cells

.1mm copper is a really thin thing. Yes weldable, some people use it, but it's really weak mechanically. I'd rather use double .2mm nickel for the same conductivity. That's just my opinion, some will disagree.
by vex_zg
Oct 09, 2017 3:50 am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 2142
Views: 64474

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

In the meantime: I asked the seller who sold me this bluetooth module if he can get more. He might be able to get some from the KT factory. Is anybody interested? I only asked because somebody here wrote BT modules can't be purchased separately. I would like to buy 3 units of this module. OK, I wil...
by vex_zg
Oct 08, 2017 11:44 am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 2142
Views: 64474

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

great work Stan with the lishui bt adapter / app.

I presume the app will only work with lishui controllers, and not KT controllers?
by vex_zg
Oct 08, 2017 6:18 am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 2142
Views: 64474

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

In the meantime: I asked the seller who sold me this bluetooth module if he can get more. He might be able to get some from the KT factory. Is anybody interested? I only asked because somebody here wrote BT modules can't be purchased separately. I would like to buy 3 units of this module. OK, I wil...
by vex_zg
Oct 08, 2017 2:29 am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 2142
Views: 64474

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

The markings on the chip are CC2540 F256 TI65J P123 G4 If the lack of BT module is a blocker to your work I can consider borrowing you this sample. Thank you. Can ypu please take the pictures with day light and maybe see if you can use the macro option on your mobile phone? And pictures also from t...
by vex_zg
Oct 07, 2017 2:35 pm
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 2142
Views: 64474

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

FYI Kunteng recently issued a bluetooth adapter which plugs into the controller instead of the usual LCD3 http://www.szktdz.com/en/news_show.php?article_id=485 I managed to get a hold of one factory sample. So perhaps you can only implement this KT or CA protocol, and use one of the android apps fo...
by vex_zg
Oct 07, 2017 3:43 am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 2142
Views: 64474

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

FYI Kunteng recently issued a bluetooth adapter which plugs into the controller instead of the usual LCD3 http://www.szktdz.com/en/news_show.php?article_id=485 I managed to get a hold of one factory sample. So perhaps you can only implement this KT or CA protocol, and use one of the android apps for...
by vex_zg
Sep 21, 2017 5:48 am
Forum: Items for Sale - New
Topic: 5-16S Smart Tiny BMS preorder - 30/150/750A rated
Replies: 135
Views: 15906

Re: 5-16S Smart Tiny BMS preorder - 30/150/750A rated

Freemann wrote:Does anybody known if its possible to use one the 3 motor hall sensor as input for the BMS?

So one hall-sensor will be connected to both the Controller as the BMS.
What would be the purpose?
by vex_zg
Sep 20, 2017 6:14 am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 164
Views: 16419

Re: Spot Welding Copper Strips to 18650 Battery Cells

Anyone tried to weld or solder 5*0.2mm nickel plated copper solar bus wire ? It's cheap, supposedly copper and already protected against corrosion and, with a cross sectional area of 1mm2, it should be able to handle 12A. I wonder how the plating would influence the welding process. I just ordered,...
by vex_zg
Sep 20, 2017 2:33 am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 164
Views: 16419

Re: Spot Welding Copper Strips to 18650 Battery Cells

Anyone tried to weld or solder 5*0.2mm nickel plated copper solar bus wire ? It's cheap, supposedly copper and already protected against corrosion and, with a cross sectional area of 1mm2, it should be able to handle 12A. I wonder how the plating would influence the welding process. I just ordered,...
by vex_zg
Sep 17, 2017 8:49 am
Forum: Motor Technology
Topic: regain throttle sensitivity after controller shunt mod?
Replies: 4
Views: 498

Re: regain throttle sensitivity after controller shunt mod?

Maybe when we have finished our OpenSource firmware for Kunteng STM8 controllers, we can develop a feature to configure different values for regen. I am always looking if I could find a way to join but I have a baby on the way and wife watching my every step :) I am not asking about anything regen ...
by vex_zg
Sep 15, 2017 5:21 pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 164
Views: 16419

Re: Spot Welding Copper Strips to 18650 Battery Cells

I did a lot of experiments with welding copper, I have a 600Ws fully programmable spot welder, can weld copper including 0.2mm and probably thicker, but my conclusion is that for sufficient mechanical strength you need at least 0.2mm copper, but to weld 0.2mm copper you need to use power levels whic...
by vex_zg
Sep 10, 2017 3:15 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

Your FET choice looks good. I haven't seen that one before. If the cap internal resistance is high, the ripple current will heat it up and they can fail from overheating. More caps will help spread out the heat, or if you can find ones with a lower IR it will help. Usually there isn't much room for...
by vex_zg
Sep 09, 2017 12:28 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

My old analog Crystalyte controller did 80A for short bursts. Continuously it could probably do 50A. Those had a very hefty heat spreader and weighed considerably more than the typical 12 FET cans you see today. If you have enough cooling to keep it from overheating, it might last for a while. The ...
by vex_zg
Sep 09, 2017 12:13 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

it's 16s, so 67.2 Fully charged. The caps are 100V, 3 of them. I could add more caps if needed. I think 3077s are too low rated with 75V Vds, since I wouldn't bet that transient spikes have been dealt with entirely. The FET side of the casing doesn't get more than some 35-40*C. I'm in Sweden so it's...
by vex_zg
Sep 08, 2017 12:21 pm
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

Ah sh** now I realized that I was using the speed switch wrong and that those 85A were in mid setting and that the max setting is probably around 120A battery DC current so probably more than 200A AC phase current. Well this can't last long. I will send pics when controller fries :) Those new FETs a...
by vex_zg
Sep 06, 2017 9:43 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

Due to imbalance one of the FETs will carry considerably more than 80A. I had a 24 FET controller carrying those kind of currents that failed multiple times. So it really depends how well the balance is achieved. The more FETs the harder it is to have good balance. You could carry a spare set for l...
by vex_zg
Sep 06, 2017 9:13 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

The FET leads must carry the motor (phase) current. They rely on the circuit board traces to pull heat out of the leads. With high current they often unsolder themselves if insufficient heat is removed, or just vanish when there's a fault. I didn't consider unsoldering, good point. In my case it's ...
by vex_zg
Sep 06, 2017 6:49 am
Forum: Motor Technology
Topic: here's a very nice 300A mosfet
Replies: 18
Views: 1288

Re: here's a very nice 300A mosfet

That package has limited production use in large parallel arrays due to legs being so rigid and tending to have PCB trace fatigue and cracking from thermal cycling stress. It's an excellent part if used correctly, but doesn't lend itself well towards an aluminum PCB due to cooling, and has limited ...
by vex_zg
Sep 06, 2017 5:31 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

I just don't get how those little legs support any more than 10amps, that's completely aside from the body. People say 'oh they're short so it doesn't matter'...I can't quite believe that. If I grabbed a piece of wire that thin and pumped 80amps through it, it would vaporise within a second so what...
by vex_zg
Sep 06, 2017 3:13 am
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Re: Can a 12FET controller handle 85A DC / 160A phase?

It'll probably last a while, but for continuous reliable operation you'd be looking at more like 30-40A max per FET rather than >80A. Well there is no turning back now! :) I'll let you know how long it lasts. I like the smaller size of a 12FET controller. I have 18FET on the way as backup. If my ma...
by vex_zg
Sep 05, 2017 3:17 pm
Forum: Motor Technology
Topic: Can a 12FET controller handle 85A DC / 160A phase?
Replies: 16
Views: 885

Can a 12FET controller handle 85A DC / 160A phase?

I have a KT40 kunteng controller, 12 x 4110 FETs http://www.szktdz.com/en/news_show.php?article_id=502 I beefed up traces etc, and did a shunt mod. This made it go to some 85A battery current / 160A AC phase current measured with clamp current meter. So in this 12FET controller of course two 4110 FE...
by vex_zg
Sep 05, 2017 7:15 am
Forum: Items for Sale - New
Topic: 5-16S Smart Tiny BMS preorder - 30/150/750A rated
Replies: 135
Views: 15906

Re: 5-16S Smart Tiny BMS preorder - 30/150/750A rated

Thanks. Just ordered it. Will try to find time to do the android app. Need wife permission :)
by vex_zg
Sep 05, 2017 5:11 am
Forum: Items for Sale - New
Topic: 5-16S Smart Tiny BMS preorder - 30/150/750A rated
Replies: 135
Views: 15906

Re: 5-16S Smart Tiny BMS preorder - 30/150/750A rated

I understand the questions might be overwhelming but if you put the answers in one place it will be easier for you in the future. Digging around hundreds of posts to mine the information is not efficient for customers either. When you find the time please explain more about current handling capacity...