Search found 1785 matches

by flippy
Feb 08 2021 1:53pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

whats the easiest way to measure the battery resistance? i wonder how conductive my somewhat weak welds are. search the "oriental supermarkets" for a SM8124A or something to that effect if you want fairly accurate and cheap for batteries under 100V. or do it the old fashioned way by measu...
by flippy
Feb 08 2021 9:12am
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 101
Views: 2047

Re: 'on board' 1.5kW charger. Which alibaba supplier?

The cell can certainly keep on taking energy post termination voltage and be what is called " overcharged" and create a dangerous situation. Go charge a cell to 5 volts.. energy WILL flow, top of charge, the resistance will climb, cell will get hot, and thermal runnaway a possibility? The...
by flippy
Feb 08 2021 7:45am
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 101
Views: 2047

Re: 'on board' 1.5kW charger. Which alibaba supplier?

That's IMO a crappy way to do balancing IMO but won't argue here. My point still stands, do not rely on the human element, for safety the normal cycling charge process - however you choose to do it - should be automatic. 98% of ALL batteries on the market today use the "4.25V balance trigger&q...
by flippy
Feb 07 2021 4:54pm
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 101
Views: 2047

Re: 'on board' 1.5kW charger. Which alibaba supplier?

The Meanwell, while great quality, are PSUs, not chargers. You need to add an HVC circuit in order to automate charge termination. Do not depend on human reliability for that. there is no charge termination with lithium. unless you have a bms with active balancing you NEED float voltage to stay on ...
by flippy
Feb 06 2021 10:25am
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 101
Views: 2047

Re: 'on board' 1.5kW charger. Which alibaba supplier?

If you want a quality charger, then the ELCON UHF 1.8kW HK-H CAN Charger is the only way to go. With CANbus: https://www.elconchargers.com/catalog/item/9034090/10295151.htm https://www.electricmotorsport.com/elcon-uhf-1-8kw-hk-j-canbus-charger.html https://evsource.com/products/elcon-uhf-1-8kw-canb...
by flippy
Feb 06 2021 8:58am
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 101
Views: 2047

Re: 'on board' 1.5kW charger. Which alibaba supplier?

Jordan325ic wrote:
Feb 05 2021 7:28pm
Being painted blue is virtually never a good sign! Were they heavy?? These are supposed to be 6lbs.
yes, they are very heavy. that is what happens when its filled with bullshit.

at least the paint made them look better....
by flippy
Feb 05 2021 4:23pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

Makes sense that u could measure capacity while charging too no? Maybe not as accurate but that energy going in..is energy going in. you stop charging at intervals so you can measure properly. and the energy going in is the least important metric. the only thing that matters is energy going back ou...
by flippy
Feb 05 2021 4:11pm
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 101
Views: 2047

Re: 'on board' 1.5kW charger. Which alibaba supplier?

they sell these painted blue with a couple scooters in my country. they are shit. i had a whole box of them, all dead.

their diodes and mosfets are utter garbage. i dont believe they are actually rated for anything north of 750W.
by flippy
Feb 05 2021 5:53am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

capacity testing is done with discharge, not charge. the IR also changes with SoC so you need to measure that at intervals during the charge/discharge as well. fuse son welder pop because you give them enough time to heat up and melt it. that is why you can push 2000A with just a 300A megafuse. the ...
by flippy
Feb 03 2021 5:15pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

These are good cells in that they’re used from batterhookup and capacity tested full capacity or within 95% by me and I only get timeout when they drop to 14v. At 16v and 31joules I had no timeouts. 5s15p a123 26650 Other than that I’d been at 31 joules and 16-15v happy for hundreds of welds with n...
by flippy
Feb 03 2021 4:20pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

But the welder “timeout” should happen if the amount of time that the welder uses isn’t enough to get out what joules it’s set to. 31joules in my case. I’ve had that happen lots of times in the past when the battery was going down to 14v. But this happens on the 16v full charge every time and when ...
by flippy
Feb 03 2021 3:52pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

even the offical bussman fuses are well under a tenner, https://www.amazon.com/Cooper-Bussmann-ANL-300-Current-Limiter/dp/B000WSWXDC I’m doing 16 volts. I guess could charge up to18 for 5s iron cells. But why you two don’t think there’s a problem w the welder? Set to 8 joules at 16v w a good battery...
by flippy
Feb 03 2021 10:51am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

100s of welds with success with same settings and now fuses pop at what should be a 1/4th the time with only 8 joules like i said: the joules dont matter. you can pop a fuse with 1 joule. a fuse is rated at "amps over time". a fuse works by MELTING the thin wire inside. just like the weld...
by flippy
Feb 03 2021 10:43am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

if it takes too long you have too much resistance or not enough volts to push the amps into the weld.

too much time = glowing fuse.

dont look at the joules, look at the pulse time.

do you keep your tips clean, leads and connections tight? the magnetic currents might loosen nuts over time.
by flippy
Feb 03 2021 10:19am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

I blew three fuses in a row even at 8 joules. Something is wrong with the welder for sure. no, you are welding with too low voltage so the current needs to be too high to get the joules. harder and faster is better. the slow cooking of the fuse is simply because it gets the time to heat up as the p...
by flippy
Feb 03 2021 7:41am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

It's a build technique specific to an application. Tesla has been using it to great success with their Model S and Model X batteries, except they have million dollar wire bonding machines. For the DIY conversion, it's a great way to go, provided you can make the interconnects. I have considered mec...
by flippy
Feb 03 2021 7:20am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

Question for the kWelders out there - can you spot weld 0.15 mm thick nickel to nickel plated 1.2 mm aluminium? How about 0.8 mm nickel plated copper? Seems like you need all the Joules :? i dont see why you would do something like that in the first place. just because you can does not mean you sho...
by flippy
Feb 03 2021 7:10am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

i keep blowing through the 300 amp fuse if anyone has any ideas what my problem is please advise me. why wouldnt this tool work?:https://www.youtube.com/watch?v=nhSuXM5RnvI if i added electrodes. what current does it put out in comparison? im guessing it is ON too long, but if you quickly connected...
by flippy
Jan 30 2021 5:19pm
Forum: Battery Technology
Topic: Open source BMS for 48V to 400V lithium-ion battery pack
Replies: 257
Views: 47765

Re: Open source BMS for 48V to 400V lithium-ion battery pack

i am not saying it should not have cool features and expensive/complicated connection options, it just should not depend on them in order to get the bloody thing to work. :wink:
by flippy
Jan 30 2021 4:58pm
Forum: Battery Technology
Topic: Open source BMS for 48V to 400V lithium-ion battery pack
Replies: 257
Views: 47765

Re: Open source BMS for 48V to 400V lithium-ion battery pack

Seriously flippy, you don't need to post anything negative/offensive here. I'm not here to do bashing on anyone's product or services. this was not meant for you, but for the current market of "high end" bms models you can buy. i dont need crap like "canbus interconnected daughterboa...
by flippy
Jan 30 2021 3:10pm
Forum: Battery Technology
Topic: Open source BMS for 48V to 400V lithium-ion battery pack
Replies: 257
Views: 47765

Re: Open source BMS for 48V to 400V lithium-ion battery pack

Yep, and as I said. it seems to works well at 100A continuous so far. At the end, there are many other parameters outside of the BMS that I cannot control and that will have a direct impact on the lifetime of the product. If you think that it would be preferable to have some datas, official documen...
by flippy
Jan 30 2021 2:10pm
Forum: Battery Technology
Topic: Open source BMS for 48V to 400V lithium-ion battery pack
Replies: 257
Views: 47765

Re: Open source BMS for 48V to 400V lithium-ion battery pack

i understand the math, but the problem is that board construction and final assembly is not as perfect as the math makes it out to be, so its always good to test if it actually reaches it ratings and if you might need to tweak some things. especially when getting near those triple digit amp numbers ...
by flippy
Jan 30 2021 12:04pm
Forum: Battery Technology
Topic: Open source BMS for 48V to 400V lithium-ion battery pack
Replies: 257
Views: 47765

Re: Open source BMS for 48V to 400V lithium-ion battery pack

Hello ENNOID, I see on your site that the solid state model only allows for 10A (20A) charging; won't that also limit regenerative braking? Cheers regen is not dependant on the charge port mosfet. its done by the main mosfets. so no. i do have a question: has testing been done on actual current loa...
by flippy
Jan 26 2021 10:34am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 193065

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

Hummina Shadeeba wrote:
Jan 25 2021 4:05pm
if getting "timeout" does that mean the battery isnt capable of putting out the joules in the amount of time given? i need a bigger battery if getting timeout?
it tells you that you need a break. take a walk, stretch a bit, grab some coffee and then come back. :lol:
by flippy
Jan 24 2021 11:33am
Forum: Battery Technology
Topic: LiFePO4 vs NMC nail penetration safety test
Replies: 2
Views: 217

Re: LiFePO4 vs NMC nail penetration safety test

conclusion: dont use batteries in that are sold in plastic bags. and for this very reason i refuse to use pouches or even allow them in my shop. if a customer has a rebuild that has them i will either remove them on their property or the customer empties the housing at their own risk. just the insur...