I’ve just finished this deep dive video, further testing the Samsung 50S and looking at power claims of some of the things using it, including the Evolve Diablo. If you’re interested in this controversial cell, check it out.
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I think people in this community have come to the conclusion that the 50s is a good cell. The EUC community is braindead and would rather stick with 50E because they can’t comprehend a datasheet
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The Diablo is not a powerful enough board for the 50S to fall short.
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I agree 50S is fine for evolve. All it needs to do is power a bunch of colourful lights and not self discharge too much over the next three years sitting in someone’s garage until it ends up on marketplace.
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Not being the type to subscribe or like to any channel, I was unaware that you had dropped a Samsung 45t video a month ago.
Good to have another cell with P45b like performance on the world market.
I’ve been very intertested in cell heating comparative data.
I notice your thermocouple is always in a slightly different spot on the cell.
@DIY500AMP.COM has an IR camera, and, IIRC, it always shows the areas toward bottom of the can being hotter than the top, so perhaps placing the sensor more precisely could yield better data in the future.
I think @Battery_Mooch removes the wrapping when he tests cells.
i wonder how much emissivity plays a role, and thermal transfer through the cell wrapping plays a role in the data
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Please subscribe to my channel. I make videos about things that are better than eskate.
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Please do NOT like or subscribe or comment on my ‘channel’!
If you know a surfboard shaper or fin designer, punch them in the throat for me.
Ducking Fouchbags.
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Yea, I test on bare cells.
In my testing, the wraps drops the temp about 2°C versus a bare cell. Depends on the wrap and sensor though. I use a calibrated type-k thermocouple.
Emissivity has a HUGE effect and the wrap must be left on if using an IR gun or camera. The emissivity of the wraps I tested was pretty close to the 0.95 that guns/camera expect but the wrap must be tight. There are some almost transparent wraps that weren’t as good.
Painting a patch on a bare cell with flat black can work very effectively for IR use but just wouldn’t be necessary IMO.
I believe @hifipj is using a thermistor?
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In addition to the process of data collection, I was wondering how the cell wrap affects the amount of heat radiated from a cell.
For example 3 cells heated to 75c evenly and thoroughly.
Cell 1 is bare, shiny steel can, no wrap
Cell 2 has flat black shrink wrap.
Cell 3 has glossy white shrink wrap of same thickness and tightness.
Which cell in clear still air cools down the fastest, and to what degree?
I’d guess the flat black wrap would cool the quickest.
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EUC now are using 50S by default. They made it the new standard about a year ago.
I agree.
Though glossy white paint might not be far behind. I’ve been surprised how all the colors seem to be fairly close (all one type, small jars of model paint, from one company). Haven’t tested gloss vs flat though.
And radiative cooling might be fairly small overall compared to convection cooling too. Even the smallest breeze from a fan can have a huge effect.
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After all of the drama and yapping
I guess if flat black cell wrap made a huge difference in radiative cooling, all the cool kids would be using it.
With a hopefully sealed esk8 enclosure, conductive cell cooling likely makes more sense to pursue, with a hot running battery.
I had interesting results with different density foam surrounding the battery transferring heat to wood deck and to fiberglass enclosure. Well, interesting in the temperature of the enclosure directly adjacent. Never got far enough along to see if it made a difference in pack temp.
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Good point…essentially zero radiative and convective cooling in an enclosure.
My guess is that the thermal resistance is too high to do too much (especially through shrink, tape, and possibly fishpaper). Though I’d also be interested in the results of testing different foams and more thermally conductive padding.
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That dead air space between cells certainly is not conducting heat away from cell cans very efficiently.
Seems anything would be better than nothing, there.
My hot running pack had 0.5mm g10 fiberglass sheet sandwiching the single stack flat pack. It was held to kaptoned fishpaper with some thin silicone, Karfuter k5. Thinner denser cushioning foam transferred more heat to fiberglass enclosure than thicker squishier foam did, noticeably.
Areas of the enclosure further away from battery, ahead of it in slipstream, were upto 10c cooler. It was not built with heat conduction in mind, but I can’t help but think about the differences if it were.
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What drama? Looks like I’m missing out.