So what brand of Lithium batteries do you sell BatMan?
I'm interested in the 3C claims, in each direction. A suggestion, the cell discharge is used to recharge a large percentage of the other cell on test. 3 cells will need to be tested at 70% discharge and 3 cells at 80% discharge. The charging and discharging will need to be done via a controlled method with digital recording equipment so charts can be seen as far as voltage sag, and recharging trends indicating changes to internal resistance. The question is, do you have the facilities to carry out this sort of testing?
Here's some advice... don't tell anyone if you do the testing.So it appears nobody has done any cycle life testing on Thundersky cells.
I find that quite amazing, given the cost of these cells, the cycle life actually determines how much the cells are worth. At $10k-$20k a pack, that is a lot of cash based on faith and battery salesman claims.
So I'm going to be doing cycle tests, I have to believe you will want to see the results, would you pay $5 to see them? I'd like to propose that I raise a collection for the tests, let's say $500, so 100 people at $5 would cover it, any less I don't publish, you get the $5 back or whatever donation has been given.
The plan is to charge them at 1c, discharge at 3c to empty, and just keep doing it is until they are dead. This takes a long time to run and destroys the cells. At 1c charge, 1 hour to charge, 20 minutes to discharge, time to rest say 10 minutes, so a cycle takes 1.5 hours. That is 16 cycles a day, 480 cycles a month. So to test the claimed 3000 cycles will take almost over 6 months of 24/7 testing.
Another set of parameters will take longer, if discharge is only .5c, it will take 3 hours to do one cycle, so 12 months of 24/7 testing.
And if one tests only discharge to 80% or 70%, another set of cells to destroy and test hardware to build and keep running.
You see this is a significant investment in time and energy to run these tests, and make sure they work property over such a long time frame.
I don't think it is unreasonable to get some financial support to do the tests.
I don't get it, you being facetious?Here's some advice... don't tell anyone if you do the testing.
Actually, I wasn't. Lots of people have invested lots of $ and time to post information of value on this site. Comments like "so 100 people at $5 would cover it, any less I don't publish, you get the $5 back or whatever donation has been given" rub me the wrong way.I don't get it, you being facetious?
I'm working on the test hardware, trying to figure the best way to do it.
I have a motor controller I built to run my electric outboard that could handle 48v and 200 amps, I sold my sailboat a long time ago, so I can repurpose it for this testing. 3C for a 40Ah battery is 120amps.
It looks like I will need about 70 of my 2600F caps to hold the discharge, but I'm not certain if that will work, because of the voltage mismatch between battery and caps
Actually, I wasn't. Lots of people have invested lots of $ and time to post information of value on this site. Comments like "so 100 people at $5 would cover it, any less I don't publish, you get the $5 back or whatever donation has been given" rub me the wrong way.
You don't publish? Look buddy, do it or don't do it. But if you do it and don't share it.... it may not go over so well. So, my advise is...if that's your game... don't tell anyone. Or, like the rest of the people on this site....share your information.
oh,...well, that's rocket science.I share plenty of information, I'm sharing how I'm going to run these tests.
It's a conspiracy. Everyone secretly knows that these cells only get 500 cycles. We all work for the Chinese on commission. When they sell to "the people who don't really know", we all get some good $$ . So ...shhhhhh.Seeing as nobody has, what could be the reason?
Jack Rickard did some testings but not over such a long period of time.
I have to say that I am skeptical that your collected data will fit the interest of all the 100 donors.
I would support the meaning of DIYguy, I blowed up some things, I got the wrong parts, replaced others and all of these experiences I would give to the community for free, because they helped me for free.
If anyone is so grateful and full of overwhelming gratitude, he could donor my project via PayPal ... if not, no problem.
I do it for hobby, not for dollars
One thought is to get Headway or A123 or similar cells. You could then do much higher currents, and get ~4 times as many cycles in the same time. The cost would be much cheaper, for both the cells and the equipment.
Careful there sunshine. Personal attacks only demonstrates a weak argument. There is a vendor section if $ is your game..Rickard just published data obtained from Thundersky.
He did do 400amp tests that killed a cell.
No one needs to run these tests to get a EV working, which is why they are not done. It is usually a university or national lab that does these kinds of tests, funded by your tax dollars.
In my opinion, knowing how to treat these cells to make them last is very important information. If you and the useless DIYGUY don't think $5 is worth finding out, then so be it. I will know how to make my EV last a long time.