Search found 437 matches

by kdog
Jan 26, 2018 2:33 am
Forum: Battery Technology
Topic: Voltage difference BMS vs direct from battery
Replies: 6
Views: 234

Re: Voltage difference BMS vs direct from battery

your BMS may be in an off state due to having not been charged. you can still detect near battery voltage on the output but if you put any load on this youll find that it drops away to zero immediately. try putting a load across it and see what happens. some BMSs require a charge to turn them back o...
by kdog
Nov 16, 2017 6:03 am
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Re: Need help with this blown KT controller

Yeha! She lives again... Hopefully for more than the first ride but so far so good.
Soldering all those little mosfet legs in is easier said than done... With all those smd parts right next door just waiting to float off or bridge to... Damn fiddly.
Thanks for the help everyone.
by kdog
Nov 16, 2017 5:57 am
Forum: E-Vehicles General Discussion
Topic: Step Down EV battery voltage for lights, alarms, etc
Replies: 4
Views: 297

Re: Step Down EV battery voltage for lights, alarms, etc

Try an AC-DC smps ( wall wart) of suitable voltage and amps on the out put. plug AC side into main battery, if it doesn't work battery voltage might not be high enough. I run my lights directly off my ebike battery... Works great.
by kdog
Nov 15, 2017 9:47 pm
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Re: Need help with this blown KT controller

To late- I already did :? It was a tiny 1mm bit that fitted through an empty hole so hopefully it's ok.
We'll see...
by kdog
Nov 15, 2017 8:58 pm
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Re: Need help with this blown KT controller

Ok my replacement mosfets arrived so I got started on the repair. I broke out the old ones and desoldered the legs one by one, then I drilled out the solder in the hole. Is there a better way to do this? ..It worked fine though. Annoyingly just one mosfet in each phase was blown, but I couldn't know...
by kdog
Nov 09, 2017 7:30 pm
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Re: Need help with this blown KT controller

Ok thanks fellas... I'll see how it goes in a day or two when the bits arrive
Cheers for the help.
by kdog
Nov 09, 2017 1:14 am
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Re: Need help with this blown KT controller

I've got 15 fets on order.. Should be here in a day or two( 3spare). Hopefully that solves it, but I'm not overly hopeful, there's always something more. :(
Is there a way to test the gate drivers? or do I just try the new fets and see.
by kdog
Nov 05, 2017 9:40 pm
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Re: Need help with this blown KT controller

I'll try to elaborate/ clarify ( but bear with me- it's not my strong point) the controller seems to be shorted in all phases- there is cogging in all combos of phase wires. There is no ebrake signal on LCD ( and this does work when I engage brake) an the controller communicates with the LCD (respon...
by kdog
Nov 05, 2017 6:12 am
Forum: Motor Technology
Topic: Need help with this blown KT controller
Replies: 16
Views: 360

Need help with this blown KT controller

Hi all A friend has asked for some help with his ebike (cause I put it together for him) it's a 500w DD hubby with a KT controller and LCD display. I built the battery for him which is a 13s6p. All pretty standard, it's been going well for 3500 k's but he's had a series of failures in a week (which ...
by kdog
Oct 28, 2017 12:47 am
Forum: E-Bike Photos & Video
Topic: Freeride Ebike QS205 22s10p sabvoton 72150 unlocked
Replies: 46
Views: 3052

Re: LUDICROUS Freeride Ebike-QS205 22s10p subvoton 72150

that's a better layout for your cells, except that in your drawing you have only 4 series connects... 200a/4= 50amps per series connect. then there is the issue of the cells nearer the connectors doing an unfair share of the load and the ones further away not pulling their weight. For 200A you NEED ...
by kdog
Oct 26, 2017 7:27 am
Forum: E-Bike Photos & Video
Topic: Freeride Ebike QS205 22s10p sabvoton 72150 unlocked
Replies: 46
Views: 3052

Re: LUDICROUS Freeride Ebike-QS205 22s10p subvoton 72150

Use .2mm Ni minimum thickness. Rearrange your pack to double the depth ( rows 10 deep)so you have 10 series connects rather than the 5 you have now. 8x.2mm Ni can take about 8-10 amps continuously and 15 for short periods. More than that heats it up quick smart. At 20A it gets hot, 30A very very hot...
by kdog
Oct 14, 2017 8:40 pm
Forum: Battery Technology
Topic: Can I spot weld copper strips?
Replies: 42
Views: 1291

Re: Can I spot weld copper strips?

DC carries more power for a given time than AC. 0.1mm cu is doable with a .3ni capable machine Slots are a given, and discussed elsewhere in detail Thicker than .1mm cu requires so much power you are approaching the limit of the can to survive. Any minor misalignment etc results in a hole perforatin...
by kdog
Oct 03, 2017 7:22 am
Forum: E-Bike General Discussion
Topic: Suspension Stems
Replies: 13
Views: 528

Re: Suspension Stems

Alright! So now it's maybe not dangerous!! :lol:
I'll stick with my pikes I reckon, Ta anyway :wink:
by kdog
Oct 03, 2017 6:29 am
Forum: E-Bike Non-hub Motor Drives
Topic: BBSHD Setup - Luna Eclipse chain ring has bent tooth
Replies: 4
Views: 335

Re: BBSHD Setup - Luna Eclipse chain ring has bent tooth

Get a bigger chain ring and run higher tooth counts on the rear. 11t sprockets are poor for power transfer both in efficiency and also rapid wear. Running even a 12t is a ~9% improvement in chain tension. Ideally you'd be minimum of about 14t on the rear but this is might be too slow with your curre...
by kdog
Sep 27, 2017 4:18 am
Forum: E-Vehicles General Discussion
Topic: Technical info on spot welding?
Replies: 9
Views: 1014

Re: Technical info on spot welding?

Oh- hahaaaa! Totally didn't see that!
Better late than never... :pancake:
by kdog
Sep 20, 2017 6:32 pm
Forum: Items for Sale - Used
Topic: Lyen 12 mofsets Controller + CA 3.1
Replies: 17
Views: 1220

Re: Lyen 12 mofsets Controller + CA 3.1

If you don't sell the CA I'd be interested. I'm in Aus though so it would depend on shipping.
What type of CA is it?
Cheers
by kdog
Sep 17, 2017 4:27 am
Forum: E-Bike Non-hub Motor Drives
Topic: After 97 blissful BBSHD miles, it's all come to an end...
Replies: 4
Views: 748

Re: After 97 blissful BBSHD miles, it's all come to an end..

Sweet best outcome. Clean them well, get all that oxide off and you should be good to go ( with your spacer)
by kdog
Sep 17, 2017 4:15 am
Forum: E-Vehicles General Discussion
Topic: Technical info on spot welding?
Replies: 9
Views: 1014

Re: Technical info on spot welding?

Hey Sam Here are my answers to your qs, not by any stretch the only answers. Too many variables without more details but anyway.. For my AC single pulse spotwelder... 1) depends but btw 2v and 20v. Most AC welders would be about 2-4v I use 6v. Cd welders are variable. 2) depends but about 800-1000a ...
by kdog
Sep 16, 2017 12:58 am
Forum: E-Bike Non-hub Motor Drives
Topic: After 97 blissful BBSHD miles, it's all come to an end...
Replies: 4
Views: 748

Re: After 97 blissful BBSHD miles, it's all come to an end..

sorry- I meant to say, before you do that, check all connections for a dodgy contact. hopefully its just something simple like that.
by kdog
Sep 16, 2017 12:57 am
Forum: E-Bike Non-hub Motor Drives
Topic: After 97 blissful BBSHD miles, it's all come to an end...
Replies: 4
Views: 748

Re: After 97 blissful BBSHD miles, it's all come to an end..

hmm sounds bad- contact luna if its still new. you will have problems trying to ship a faulty battery though... as is I don't think you can. but if you want/need to go it alone, sounds like there's a short in the battery somewhere. you'll need to open her up to get an idea. could be simple :) could ...
by kdog
Sep 14, 2017 9:58 pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 159
Views: 14322

Re: Spot Welding Copper Strips to 18650 Battery Cells

Just over a month ago I did these... image.jpeg Which I was really happy with. A really solid DIY method for providing a high current solution for series connects. The only draw back was that it took ages to do all the welding. It probly took me 20hrs to cut, shape, weld all the nickel to the copper...
by kdog
Sep 09, 2017 4:11 am
Forum: Battery Technology
Topic: Fixing a (new) dud 36V10Ah battery pack.
Replies: 35
Views: 1198

Re: Fixing a (new) dud 36V10Ah battery pack.

15mins to 3.2 then 80mins to 3.5 is a positive sign... Fingers crossed.
by kdog
Sep 08, 2017 11:55 pm
Forum: Battery Technology
Topic: Fixing a (new) dud 36V10Ah battery pack.
Replies: 35
Views: 1198

Re: Fixing a (new) dud 36V10Ah battery pack.

I guess you could use the 3v power supply but I'd go with the 4.75v cause it'll be a bit slower, and the 3v one will stop charging at 3v, which is fine but the power is a bit high (1a. Yes you can connect both v meter and power supply but it'll be in accurate (high). Measure whilst off the charger f...
by kdog
Sep 08, 2017 6:07 am
Forum: Battery Technology
Topic: How can I discharge a 36v battery pack
Replies: 11
Views: 436

Re: How can I discharge a 36v battery pack

Take the element out of an old 2000w heater and dump the power into that. it'll probly run near 6-700w (assuming you're on 110v) if that's too high choose a lower wattage one. Put it in a bucket of water if it needs cooling or blow it with a seperate fan. Old school kettle would probly work too. Ple...
by kdog
Sep 08, 2017 1:42 am
Forum: Battery Technology
Topic: Fixing a (new) dud 36V10Ah battery pack.
Replies: 35
Views: 1198

Re: Fixing a (new) dud 36V10Ah battery pack.

this is fine to do at home, just be sure on your connections, polarity and monitor temp and voltages (never above 4.2 never below 2.5 (well after this episode!)) id check it like a newborn say every 10 mins (depending on your parenting style). Aim for no more than 0.05V between the cells at the end ...