Review on ELEFLY 21.6V 4.5Ah Replacement For Dyson V8 Battery, Compatible With Dyson V8 Animal V8 Absolute V8 Fluffy V8 Motorhead Cordless Stick Vacuum Cleaner by Darrius Frison

Like all lithium batteries - especially ones that remain fully charged most of the time, and get run down to zero routinely - the original Dyson ones worked well for a short while, then poorly for a long while, then wouldn't hold a charge long enough to clean one room. After selling my first born to get the vacuum, I had no intention of paying Dyson's exorbitant price for commodity cells that just happened to be packaged into their proprietary shaped plastic case.After a bit of research, I settled on this ELEFLY battery. We've been using it for a few weeks, and the runtime seems as good as the original so far.The only problem is that the plastic case of this battery is ever-so-slightly larger than the Dyson one, so it sticks in the wall-mounted charger. As a result, removing it from the charger the first few times tore the drywall anchor out of the wall. For comparison, we took the original Dyson one in-and-out of that same wall charger almost daily for several years, with no problems. I'm going to have to figure out exactly where this one is sticking and grind it down or lubricate it or something.Lastly, I can't imagine that this battery is actually 4500mAh - either that, or the OEM battery isn't actually the 2800mAh listed on it's sticker. I'm no scientist, but I know enough about batteries to know that you can't store more energy in cells of the same chemistry, of the same size. I haven't pried the old case open, but I'm guessing there's a handful of 18650 cells in there. I did weigh both battery packs, and they're virtually identical (the ELEFLY one was a few grams lighter).So, I'm giving this 4 stars (-1 for the charger fit issue) because it meets my expectation of being equivalent to the OEM battery. If your expectation is that this is going to last 1.6 times as long as the Dyson, you'll probably be disappointed. My recommendation - save a few bucks, get this battery, and be happy that it's as good, even if it's not magically higher capacity.(If my comments about battery capacity are wrong then. hmm, there doesn't appear to be a way to comment on a review. Maybe downvote my comments? Or post a better one? I haven't taken the time to hook either the Dyson or ELEFLY battery packs up to my analyzer and discharge them and quantify the capacity. If there is some magic that allows this replacement pack to store more energy, in the same size/weight, and with the same charger, please post some authoritative information - I'd love to know if that's possible and, if so, how it works. Maybe these cells are actually a different chemistry than the originals, and they're only using the Dyson charger as a power supply for their own internal charging controller.)