Search found 192 matches

by flippy
Dec 11, 2017 6:20 am
Forum: Battery Technology
Topic: Super capacitors to save battery life?
Replies: 41
Views: 649

Re: Super capacitors to save battery life?

For the weight balance it would logical to have 2 batteries on either side of the bike. But it would indeed be prudent to both batteries at the same time. It would extend the life of both packs and increase range.
by flippy
Dec 09, 2017 7:17 pm
Forum: Battery Technology
Topic: Super capacitors to save battery life?
Replies: 41
Views: 649

Re: Super capacitors to save battery life?

there is absolutly no reason to use those LTO batteries. a 3kW pack made of regular 18650's can be charged with 2kW+. st such a large capacity the question is not "can you carge it fast enough", the question should be "can the outlet deliver the wattage without popping the breaker of the establishme...
by flippy
Dec 09, 2017 12:57 pm
Forum: Motor Technology
Topic: Game Changer Page 3 with video of 1700amps!!!!
Replies: 84
Views: 9411

Re: Game Changer Page 3 with video of 1700amps!!!!

i know the old style connectors suck by todays standards. (the new stuff is quite nice actually. but lets be honest, if you are messing around like we are with currents well into the triple digits you need to think hard about what you are doing. and everyone knows that there are people that will thi...
by flippy
Dec 08, 2017 2:52 pm
Forum: Motor Technology
Topic: Game Changer Page 3 with video of 1700amps!!!!
Replies: 84
Views: 9411

Re: Game Changer Page 3 with video of 1700amps!!!!

i am talking about using proper milspec connectors rated for the task, not stuff to fix dodgy undersized connectors.
by flippy
Dec 08, 2017 8:43 am
Forum: Battery Technology
Topic: So confused, please help (24s 99.6V battery charging/safety)
Replies: 20
Views: 300

Re: So confused, please help (24s 99.6V battery charging/safety)

999zip999 wrote:
Dec 07, 2017 3:12 pm
I would like to know how those cells handle that motor and controller and at what amps
they can do about 100A.
by flippy
Dec 08, 2017 7:19 am
Forum: Motor Technology
Topic: Game Changer Page 3 with video of 1700amps!!!!
Replies: 84
Views: 9411

Re: Game Changer Page 3 with video of 1700amps!!!!

its stupidly expensive and is not a solution for having crappy connections. just get better connectors to solve the problem at its base. if you are really paranoid you can get milspec stuff.
by flippy
Dec 08, 2017 4:27 am
Forum: Battery Technology
Topic: Super capacitors to save battery life?
Replies: 41
Views: 649

Re: Super capacitors to save battery life?

with your "desired" weight target of around 30 pound you are basically on the same weight as my battery i have built for my 30mph scooter. if i were to re-build that battery with high capacity B panasonics instead of the PF cells i used then i could make a 4+kWh battery that would still be under 40 ...
by flippy
Dec 07, 2017 8:02 am
Forum: Battery Technology
Topic: Super capacitors to save battery life?
Replies: 41
Views: 649

Re: Super capacitors to save battery life?

tesla charges to 4.05v and if you enable range mode you get 4.1v. but you need to enable that every time you charge.
and why buy tesla cells when you can just buy NCR18650B's from most retailers?
by flippy
Dec 07, 2017 3:44 am
Forum: Battery Technology
Topic: Super capacitors to save battery life?
Replies: 41
Views: 649

Re: Super capacitors to save battery life?

in you case i would recommend going to a specialist and get a custom battery made for your bike with regular high end 18650's. form factor can be made exactly to spec instead of huge square blocks and under 2 inches wide if needed. having the abillity to closely monitor and change settings of your b...
by flippy
Dec 05, 2017 6:10 pm
Forum: Battery Technology
Topic: Super capacitors to save battery life?
Replies: 41
Views: 649

Re: Super capacitors to save battery life?

your batteries are wrong for the use case. if you charge up to 4.1v and cut off at 3.2 you should get thousands of cycles, not dozens. get the proper cells for the task at hand and make a battery with the proper capacity. a battery within spec is a happy battery. in order to help you answer these fo...
by flippy
Nov 07, 2017 4:06 am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 649
Views: 89755

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

i am running it on 220. you do need a heavy MCD (al LEAST a C rating) in order to prevent it popping the MCD when turning it on. or use a in line resistor and an bypass switch to control the massive short that the transformer creates when powering on. i was running it quite hard, full power is neede...
by flippy
Nov 02, 2017 4:09 am
Forum: Battery Technology
Topic: Plausible to build custom variable voltage Lion charger?
Replies: 30
Views: 848

Re: Plausible to build custom variable voltage Lion charger?

that thing is not suitable for lipo. lead only.
by flippy
Oct 23, 2017 12:03 am
Forum: Battery Technology
Topic: Plausible to build custom variable voltage Lion charger?
Replies: 30
Views: 848

Re: Plausible to build custom variable voltage Lion charger?

if you want short charge times you should get a more powerful charger that is limited by what current the battery can handle. when the current tapers off too about 0.3A per cell you are at about 4.1v at rest. this does not work for high cell count packs above 10kg or so as you would need a 4+kW char...
by flippy
Oct 21, 2017 5:03 pm
Forum: Battery Technology
Topic: Plausible to build custom variable voltage Lion charger?
Replies: 30
Views: 848

Re: Plausible to build custom variable voltage Lion charger?

the problem with keeping cells on the charger is that it forces the cell to keep 4.2v. something the cell does not want to do. keeping cells at 4.2v for extended periods kills them slowly. this is not a issue if you keep them at 4.05v, then you can keep them floating on the charger until the cows co...
by flippy
Oct 06, 2017 8:08 am
Forum: Battery Technology
Topic: Your DIY battery weight survey
Replies: 11
Views: 480

Re: Your DIY battery weight survey

I got a 4.2kWh battery. I am not taking it outbof my scooter to weigh it. But it should be a hair under 20kg.
by flippy
Oct 05, 2017 7:13 am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 649
Views: 89755

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

yes i used the welder from him for a 200 cel pack and i like it. the only problem is that my battery is a bit too much i think. i need to have it at 2~3ms at best because of the insane current my 60Ah lifepo4 pack (60Ah winston cells) can deliver. it's weird to need to have a more shitty battery in ...
by flippy
Sep 17, 2017 3:45 am
Forum: Battery Technology
Topic: 18650pack cell protection idea. PTC + fuse & diode).
Replies: 1
Views: 229

Re: 18650pack cell protection idea. PTC + fuse & diode).

Read into how a PTC works. More power means more heat wich means more resistance. It is not a "switch". You will physically burn out the pack due to heat generation.

Buy a proper bms, its cheaper once you add up the cost of building such a rube goldberg sysyem.
by flippy
Sep 10, 2017 3:18 am
Forum: Battery Technology
Topic: BMS limiting my charge to 54V
Replies: 9
Views: 346

Re: BMS limiting my charge to 54V

It sounds like the charger is working properly but the BMS is sensing a high cell and stopping charge early. It's possible the pack is just out of balance too far for the BMS to compensate in a reasonable time. Need to measure those cell voltages. This. Dont be a dumb idiot and check voltages. The ...
by flippy
Sep 04, 2017 9:33 am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 649
Views: 89755

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

I saw that welder as well when looking for a replacement. But in the end i would face the same problems with overheating and popping MCB's that i went "frock it" and bought a battery based welder. Much more effixient, no more extentions from the breakerbox for the dedicated D class MCB i had for it....
by flippy
Sep 03, 2017 11:32 pm
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 649
Views: 89755

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

its basically even smaller then a microwave core. not really usable. considering the primary core blew up means it will need a full rebuild. no way i am going to put that effort into it.

and i already have a good 180W temp controlled soldering iron.
by flippy
Sep 03, 2017 2:41 pm
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 649
Views: 89755

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

https://i.imgur.com/QJ5oEkJh.jpg and that was the end of a sukko 709. had to run it on full power to weld 0.15 and after about 5000 welds it finally gave up with a huge flame, one popped D16 in the distribution box and one entire house smelling like someone blew up a 1970's stereo by running the am...
by flippy
Aug 14, 2017 5:48 am
Forum: Battery Technology
Topic: 18650 Cell Source
Replies: 44
Views: 2347

Re: 18650 Cell Source

Which is completely unprofessional and insufficient. there is only 1 or 2 shipping companies that deal with shipping large quanitites of dangerous goods in europe. there are simply no other options. i dealt with the same issue for my work. such companies are horrible to work with but you have no ch...
by flippy
Jul 17, 2017 2:34 am
Forum: Motor Technology
Topic: 10" hub motor rubs after new bearings
Replies: 1
Views: 125

Re: 10" hub motor rubs after new bearings

found the problem and solution: due to heating of the side covers that hold the bearings it warped slighty. removed everything and bolted the covers (without stator and bearings) to the hub and reheated the covers to straighten them again. removed one cover after cooling, heated the other one still ...
by flippy
Jul 16, 2017 12:26 pm
Forum: Motor Technology
Topic: 10" hub motor rubs after new bearings
Replies: 1
Views: 125

10" hub motor rubs after new bearings

I have "rebuilt" my 10"hub motor (scooter, not a bike) with new SKF bearings to replace the chinesium ones that were completly shot. had to resort to using propane to heat it up to get them out. i just froze the new bearings and tapped them in. removed all the rust (a bit from water that got in) fro...
by flippy
Jul 10, 2017 6:22 am
Forum: Battery Technology
Topic: 18650 Cell Source
Replies: 44
Views: 2347

Re: 18650 Cell Source

there is plenty to find on the forum if you seach for "current volt mod charger" or something. i basically bought a 1.2kW charger for my moped and asked the factory (aliexpress/baba) to add a volt and current knob on the front of the unit wich they were happy to do. you can also just open it up, and...