Search found 2086 matches

by flippy
May 12 2021 3:50pm
Forum: EScooters/EMotorcycles
Topic: More low end torque for up hill climbing power
Replies: 15
Views: 295

Re: More low end torque for up hill climbing power

does the motor even have a temp sensor? i am willing to bet it was the controller that shit the bed.
by flippy
May 12 2021 2:05pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1339
Views: 206820

Re: kWeld - "Next level" DIY battery spot welder

the Kcap has balancing on board. you only have to feed it 8V. i use a mean well HRP-300-7.5. it works perfectly even when doing rapid fire welding. but you are not faster then the recharge speed. unless you are really on the ragged edge with copper and/or phat nickel 0.3 welds you dont need to worry...
by flippy
May 12 2021 7:27am
Forum: Battery Technology
Topic: Amount of cells? many or few
Replies: 145
Views: 2662

Re: Amount of cells? many or few

stop with the outright mistreatment of facts. your opinion is NOT facts and $/kWh is not a factor when talking about safety. if you want pouches to be at the same safety level as cyclindrical cells are you need a LOT more money and mass to compensate the fact that you MUST have compression and crash...
by flippy
May 12 2021 6:02am
Forum: Battery Technology
Topic: Amount of cells? many or few
Replies: 145
Views: 2662

Re: Amount of cells? many or few

My honest truth id dump 18650 on a bike and go for a prismatic less connections to worrys about and on a bike that bashes about the road vibration is gonna find any weak links over time so for road use id want a fully potted pack like tesla do it or prismatics with flexible tap connections to absor...
by flippy
May 11 2021 12:20am
Forum: Battery Technology
Topic: Amount of cells? many or few
Replies: 145
Views: 2662

Re: Amount of cells? many or few

i dont use that double row stuff for this reason. its too restrictive for most pack designs or real high currents. and often cheap steel. i use hex shaped holders only if there is a space restriction. otherwise i only use straight holders so the pack is stronger and there is more air between the cel...
by flippy
May 10 2021 7:01pm
Forum: Battery Technology
Topic: Amount of cells? many or few
Replies: 145
Views: 2662

Re: Amount of cells? many or few

the pic is from a very old pack i made long ago and was halfway during construction. you use 8mm because that is what you are already using. there is zero reason to use a different strip for that. prehaps thinner like .1 or .15 if you are doing the series with .2 for example. ps: 8mm fits exactly in...
by flippy
May 10 2021 6:35pm
Forum: EScooters/EMotorcycles
Topic: More low end torque for up hill climbing power
Replies: 15
Views: 295

Re: More low end torque for up hill climbing power

https://kellycontroller.com/shop/kls-mn/ 72V and the amps is a budget concern. more give you more power and higher efficiency and helps preventing hitting the "amp-wall" as you are bound to upgrade more parts. next stop will probably be a aftermarket 4~8kW QS motor for example. if you want...
by flippy
May 10 2021 5:02pm
Forum: Battery Technology
Topic: Amount of cells? many or few
Replies: 145
Views: 2662

Re: Amount of cells? many or few

the parralel strip only keeps the cells in balance. it does not carry any meaningful current. that is why they go on top last and generally stick out the side so you can attach your balance leads. extreme/perfect example in this 20S18P pack: https://i.imgur.com/tNN0dEp.jpg note that there is just a ...
by flippy
May 10 2021 1:12pm
Forum: Battery Technology
Topic: Makita battery built in bms at 36v?
Replies: 7
Views: 405

Re: Makita battery built in bms at 36v?

I have batteries with BMS they are 36v 9ah. My question is can i connect 4 em series to make 144v nominal and then have 13 groups (117ah) of this 4 batteries in parallel (total of 52 batteries) ?? no, it cant. if you read the datasheet for the mosfet you can see that its only rated for 85V max so i...
by flippy
May 10 2021 9:05am
Forum: Battery Technology
Topic: DIY surron 72V battery build (my first battery build)
Replies: 9
Views: 655

Re: DIY surron 72V battery build (my first battery build)

dont use epoxy. it blocks the venting capabillity of the PTC wich prevents a cell from going "ppppht" instead of "boom".
by flippy
May 10 2021 4:15am
Forum: EScooters/EMotorcycles
Topic: More low end torque for up hill climbing power
Replies: 15
Views: 295

Re: More low end torque for up hill climbing power

i dbout your original motor actually is 3kW. its generally just a upselled 1.5~2kW motor they sell as 3kW because the controller puts out 3kW. if you still have the original controller you need to replace it with something better first. a kelly is generally the cheapest way to get more power.
by flippy
May 08 2021 2:01pm
Forum: Battery Technology
Topic: Super Capacitors for "Burst Mode"?
Replies: 34
Views: 1903

Re: Super Capacitors for "Burst Mode"?

Bazaki wrote:
May 08 2021 1:14pm
Just a fantasy guys I want to share. Wrong idea?
yes, wrong idea. capacitors dont work that way.
by flippy
May 08 2021 10:26am
Forum: EScooters/EMotorcycles
Topic: special pleading
Replies: 70
Views: 1912

Re: special pleading

most industrial motors (parker just to name 1 brand) sells their motors with or without integrated brakes.
by flippy
May 08 2021 8:18am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 531
Views: 87927

Re: Spot Welding Copper Strips to 18650 Battery Cells

i havnt done testing, but if you have say 120mm wide pack that fits in a frame and can't be wider, and you want to pull say 250 or 300A from that pack, i think it would be tricky to get enough nickel in there. provided you have the right welder, its really not much work that is what i am interested...
by flippy
May 08 2021 3:28am
Forum: Battery Technology
Topic: bluetooth BMS?
Replies: 1655
Views: 221363

Re: bluetooth BMS?

dont go below 0.05V. below that they tend to start messing up. the black units with active balacing can go lower to 0.005 because they have better components.
by flippy
May 08 2021 3:25am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 531
Views: 87927

Re: Spot Welding Copper Strips to 18650 Battery Cells

has someone done any A-B testing in how much you actually gain from this in terms of current load compared to 0.15,0.2 and 0.25 x8mm nickel with actual temperature measurements and (sustained) current loads? this is very interesting in concept but we can all agree that its a LOT of work and added po...
by flippy
May 07 2021 3:28pm
Forum: Battery Technology
Topic: Ebay Kastar 12v 12AH SLA-cased LiFePO4 - AVOID
Replies: 5
Views: 156

Re: Ebay Kastar 12v 12AH SLA-cased LiFePO4 - AVOID

I was going to respond with something addressing your point, but after reading a few of your posts I've determined that would be a waste of time. Enjoy your righteousness. trust me, i made mistakes like this in the past, very expensive mistakes. i am here on this foum to help people avoid making th...
by flippy
May 07 2021 4:36am
Forum: Battery Technology
Topic: Nickel welding strips - current capability ??
Replies: 17
Views: 7104

Re: Nickel welding strips - current capability ??

OK I'll bite! What is the real current rating for .2mm x 7mm in pure nickel? simple: it depends on the application. ok, fair enough. not so simple... :mrgreen: the "heat" issue is really a time issue. you can pump 75A into such a strip if the time was short enough. you have to look at the...
by flippy
May 07 2021 3:05am
Forum: Battery Technology
Topic: Ebike Battery stored for a long time
Replies: 23
Views: 632

Re: Ebike Battery stored for a long tome

distilled water only works if the battery was cooked. Doh! Just before seeing this I had added distilled water and started the charging process. We shall see! Worse case scenario is I spun my wheels and got nowhere with my already mostly dead batteries. use a IR meter and measure the temperature of...
by flippy
May 06 2021 6:19pm
Forum: Battery Technology
Topic: Ebike Battery stored for a long time
Replies: 23
Views: 632

Re: Ebike Battery stored for a long tome

distilled water only works if the battery was cooked.
by flippy
May 06 2021 6:02pm
Forum: Battery Technology
Topic: Nickel welding strips - current capability ??
Replies: 17
Views: 7104

Re: Nickel welding strips - current capability ??

I'm highly skeptical that the chart you posted is accurate! you should be secptical. the chart is wrong. and dont be afraid to use your "real" account. too many people here are too scared to say something that might offend something or brings their plans and ideas back to reality with dan...
by flippy
May 06 2021 9:30am
Forum: Battery Technology
Topic: WTB Battery Relay Controller 100V 20S
Replies: 8
Views: 192

Re: WTB Battery Relay Controller 100V 20S

you do know that a bms and a "voltage programmable relay" are basically the same thing right? you are not switching 100VDC at dozens of amps with cheap chinese relays. you need contactors and those consume more power then you care for. a bms is litteraly designed to do exactly what you wan...
by flippy
May 06 2021 7:12am
Forum: Battery Technology
Topic: WTB Battery Relay Controller 100V 20S
Replies: 8
Views: 192

Re: WTB Battery Relay Controller 100V 20S

No that is not what I want. I am charging my packs with a balanced charger. I HATE BMS. I want a low voltage disconnect by relay. Any better proposal? yes, i have a perfect device that does EXACTLY what you need. its called a BMS. that you "hate" a bms is separate from the fact that from ...
by flippy
May 06 2021 6:23am
Forum: Battery Technology
Topic: WTB Battery Relay Controller 100V 20S
Replies: 8
Views: 192

Re: WTB Battery Relay Controller 100V 20S

these devices are fairly common. its called a BMS and your battery already should have one. and your charger would never get above 84V unless you are doing something stupid with the wrong model charger.