That would actually make way more sense, especially with the cheaper chinese packs that use nickel for the series connections.
I really think we need to come up with a standardized way of testing fully built batteries, as battery performance is typically the bottleneck for most builds and battery performance can vary greatly depending on grade of cells, and how it was constructed.
Only issue is accurate IR tester’s are fuckin pricey or absolute garbage.
you can figure the battery resistance using ohms law. its a high voltage pack and will need a stout resistance in series but not too hard to set up.
like this guys voice
https://www.bing.com/videos/search?q=measuring+the+resistance+of+a+battery&view=detail&mid=36F59FCA51B1D7C59C4A36F59FCA51B1D7C59C4A&FORM=VIRE
nought point nought
Do you know if using a grinding stone to grind the excess bits of a cell will damage the heatshrink?
Also what kind of grinding stone is used?
What excess bits of a cell?
If you are referring to remains of old spot welds then no as long as you are careful.
Almost any Dremel type grinding stone will do the job.
Yeah that.
From what I understand lithium ion batteries are a bitch to get accurate IR readings on. I do have a tester but even on a single 18650 results vary a lot, this becomes even more of an issue when you are trying to test entire packs at once instead of just a few cells at a time.
Even further there’s a bit of debate coming out of how much IR resistance actually tells you these days with lithium ion and all the extra additives that slightly alter the chemistry can make the cells have wildly different IR’s depending on the testing method (DC load vs AC frequency).
It seems the most accurate method for getting the full picture of L-ion cell health/performance is to test the electrochemical dynamic response of the cells which will measure ion flow by testing across a wide range of AC frequencies. Essentially telling you everything you need to know in terms of cell health and performance, this is really the only way to test a full pack reliably and be able to compare to to any other pack around the world easily.
Now put it on a backpack and go to the airport. Remember to wear all of your safety equipment and full face helmet. What could possibly go wrong? 
I can’t have any luck, can I?
Just found out the Turnigy nano-tech Lipo pack I got for my k-weld has a broken cell. 
The pack can’t supply any current at all. Cell #2 just drops all the volts when any load is applied.
Where did u get it? Hobbyking is sending me a replacement 20k lipo that had a bad cell, no charge to me
Hobbyking, yeah. already put in a claim.
Hope it goes through without any problems.
One of our guys also did some tests. IIRC data seemed to line up exactly with the table fro ES.
Hi All,
First time Unity user, installed on my new build. Having issue with power staying on, momentarily stayed on then shut-off. The power on sequence is halo angel switch >> Unity switch.
Thanks in advance for your help.
Power layout:
I don’t get what you are saying.
Also the diagram is obviously not for a unity as it only has a single battery connection
Kweld with kCap supercapacitors
I personally wouldnt trust buying new sunkko 220/110v welders because they have good bad bad batches and its a risk with what you will end up
If you get a bad one, they will refund you the welder+shipping but not the taxes, dont ask me how I know haha
I can buy a sunkko with Amazon prime protection (refund on return, no questions asked)
I like the kweld. My friend uses one and it works well. But i dont want lipo, so no kweld for me
It can be powered with supercapacitors and a power supply running on mains
If you can get a sunkko like that thats really good, but i doubt that it will be able to make welds better than kweld, and the electrodes for it you can make easy at home
I tried only one sunkko, it was crap and the company has fallen in my eyes a lot so Im biased a little.
If your getting a sunkko get one where you can plug in some kind of electrodes you hold in hand
Thanks for the reply.
Diagram corrected, single battery connection.
I have a switch that is connected to BMS E-switch. To power up the system, the Unity would not turn on unless I first switch on the BMS E-switch.
Also, is there a way to bypass the e-switch, just use only Unity switch to power up?
Of course, the BMS is the first link in the chain.
Unless you turn on the BMS , no power goes to the Unity.
So you first need to turn on the BMS (a latching switch is required) then the Unity using it’s own momentary switch.
If you short the BMS switch then it will always be on and you can use the Unity switch only.
I do have a latching switch connecting to the BMS e-switch. Power on stayed on momentarily then the whole system shut down.
