Thundersky's pre-date the Winston/Sinopoly/Balquon split. Since that time of Thundersky, it is reputed that the more modern Winstons have higher manufacturing tolerances, improved chemical and build quality. Also the addition of Yttrium (The "Y" if LiFeYp04) is supposed to improve extreme cold weather performance.
IMPORTANT - some very old ancient documentation on Thunderskys show them as having / needing an initial charge to 4.2v per cell. DO NOT DO THIS. Likewise, 2.5v per cell as a discharge limitation is not something to use as an LVD. This is akin to setting a lead-acid LVD to 10.7v - too low, don't go there. Unfortunately, you may see these ancient specs in some modern commercial "drop in" lifepo4 replacements. I guess they didn't get the memo 4 years ago.
My inclination is to leave the old Thundersky's in the hands of experienced practitioners, not a first timer. Again, I have no personal experience with anything but GBS, but would be cautious about old stock Thunderskys - I'd have to verify the storage voltages myself to make sure that no cell is dead from improper high-heat storage or mishandling over the years.
Here is an example of a 12v / 400ah bank of Winstons undergoing testing for marine use. Note that this test goes WAAAY too far in discharge, something we should never experience:
While he took this down to nearly 100% DOD discharge, there is no indication that he limited current during the recharge at that low DOD!! If you go under 80% DOD, you should not apply any more than about 0.01C until the cells reach 3.2v again - whereupon you can apply normal charge current. So don't go below 80% DOD in the first place, and of course never leave a lifepo4 in a badly discharged condition for very long. Get to it asap.
Note that for my land-locked system, I'll be having none of that rat's nest, but simple pack-level maintenance as described here:
Cool. Just make sure he knows what he is doing, ie using a torque wrench set to the proper specs for the terminal connections, and also making sure that the terminals and links are clean before assembly. Last thing you need is a high-resistance terminal here, and having the bms mask the issue with incessant balancing, or melting the case around the terminals. Basic battery care really.
Yes. This prevents any side or top-torque breaking or twisting the cell terminals if the cells were just loosely assembled and sat down. Any significant movement without banding/strapping and game over. Tall cells operating under high-heat environments have been reported to slightly buckle or sag, and this is also bad, since you don't want any expansion within the case itself separating the anodes/cathodes away from each other. Under abusive over or undercharge practices, the cells can expand, but having them strapped and banded is not a cure for improper charging! Don't do that in the first place.
IMPORTANT - some very old ancient documentation on Thunderskys show them as having / needing an initial charge to 4.2v per cell. DO NOT DO THIS. Likewise, 2.5v per cell as a discharge limitation is not something to use as an LVD. This is akin to setting a lead-acid LVD to 10.7v - too low, don't go there. Unfortunately, you may see these ancient specs in some modern commercial "drop in" lifepo4 replacements. I guess they didn't get the memo 4 years ago.
My inclination is to leave the old Thundersky's in the hands of experienced practitioners, not a first timer. Again, I have no personal experience with anything but GBS, but would be cautious about old stock Thunderskys - I'd have to verify the storage voltages myself to make sure that no cell is dead from improper high-heat storage or mishandling over the years.
Here is an example of a 12v / 400ah bank of Winstons undergoing testing for marine use. Note that this test goes WAAAY too far in discharge, something we should never experience:
While he took this down to nearly 100% DOD discharge, there is no indication that he limited current during the recharge at that low DOD!! If you go under 80% DOD, you should not apply any more than about 0.01C until the cells reach 3.2v again - whereupon you can apply normal charge current. So don't go below 80% DOD in the first place, and of course never leave a lifepo4 in a badly discharged condition for very long. Get to it asap.
Note that for my land-locked system, I'll be having none of that rat's nest, but simple pack-level maintenance as described here:
I don't think I will have a problem assembling the individual cells with my friend who is in the solar industry.
Do all battery cell banks need to be strapped to prevent expansion?
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