OUNCESMUSIC Posted November 12, 2018 Share Posted November 12, 2018 I was looking at some different portable battery packs on amazon and began looking at ones with ac outlets which I've considered in the past for my laptop. My uneducated assumption is more up to date higher capacity/output versions might work on a smaller (bat.cap.) and lower voltage wheels. May test this unless others have experimented with this in the past. Been wanting one with an ac and I just picked up for pennies a small bat.cap. wheel I woulndt mind testing it on. Thoughts.... Thanks. Link to comment Share on other sites More sharing options...
meepmeepmayer Posted November 12, 2018 Share Posted November 12, 2018 Can you link to an example? Link to comment Share on other sites More sharing options...
OUNCESMUSIC Posted November 12, 2018 Author Share Posted November 12, 2018 Only been looking through a few but here are some I left open in tabs for some reason.https://smile.amazon.com/dp/B07F119R6P/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B07F119R6P&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=f0dedbe2-13c8-4136-a746-4398ed93cf0f&pd_rd_wg=keF6w&pf_rd_r=9PYYYKHJ89ATCDN5NT3T&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=Ep8Uf&pf_rd_i=desktop-dp-sims&pd_rd_r=a561b59e-e6a0-11e8-a875-091c391444d5https://smile.amazon.com/dp/B0713XJBG2/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B0713XJBG2&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=f0dedbe2-13c8-4136-a746-4398ed93cf0f&pd_rd_wg=ydixS&pf_rd_r=D2GD8PK7SANKPXT6ZY1K&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=5TfAI&pf_rd_i=desktop-dp-sims&pd_rd_r=8357911a-e6a0-11e8-b82c-21b13ea86793 Link to comment Share on other sites More sharing options...
Chriull Posted November 12, 2018 Share Posted November 12, 2018 @Oswald Valentine-Lopez unfortunately they just give the mAh without the voltage. Since the first one not even gives a full charge to (some) notebooks it is not interesting for EUCs. It includes all the charging electronics and power electronics to produce ac output! For lower cap wheels its easier and cheaper to take a spare battery pack... Link to comment Share on other sites More sharing options...
FreeRide Posted November 12, 2018 Share Posted November 12, 2018 3 hours ago, Chriull said: @Oswald Valentine-Lopez unfortunately they just give the mAh without the voltage. .... With those mAh rating it very save to assume this is for a single cell/group so the voltage should be 3.6V or (3.7V if you are the optimistic type). I have a 50KmAh and a 100KmAh bank, and ones that's a bit lower (40K I think). So I calculated these two at 3.6x23.2 = 83.5Wh and 3.6x42 = 151Wh. Given the loses on the Inverter, and the fact that it probably drops out before the cells are at 2.5V, one would have to expect less than theoretical capacity. Not really too useful for EUC. I have a not so portable 865Wh Dewalt PowerStation, but I've never plugged my EUC, segway, or scooter charges into it. It's modified sine-wave, but it probably would be OK. If I really needed something like this I'd go with a DC/DC converter directly into a Li charger circuit so as to reduces losses to a minimum. Or get a model that it is easy to swap battery packs one, that is the best approach right now. Link to comment Share on other sites More sharing options...
meepmeepmayer Posted November 13, 2018 Share Posted November 13, 2018 2 hours ago, FreeRide said: I have a 50KmAh and a 100KmAh bank, and ones that's a bit lower (40K I think). So I calculated these two at 3.6x23.2 = 83.5Wh and 3.6x42 = 151Wh. Given the loses on the Inverter, and the fact that it probably drops out before the cells are at 2.5V, one would have to expect less than theoretical capacity. Not really too useful for EUC. My brain just hurt a little And the worst part is, I can't even blame you for writing it like this, because that's just consequent to how others do it and therefore for comparing sizes. Everyone is guilty, me included. "2900mAh cells", "3500mAh cells" (well, at least there it saves one from having to use a decimal separator still no excuse) While we're on off topic, why in the devil's name are battery capacities given in Ah instead of Wh? Is current really more important than power in real life considerations? I still don't know the voltage of my phone battery and how much energy actually is in there... All hail SI units! Currently enjoying the thought of my ACM's 4.6MJ battery Link to comment Share on other sites More sharing options...
Chriull Posted November 13, 2018 Share Posted November 13, 2018 6 hours ago, meepmeepmayer said: While we're on off topic, why in the devil's name are battery capacities given in Ah instead of Wh? Is current really more important than power in real life considerations? I still don't know the voltage of my phone battery and how much energy actually is in there... In these product describtions the mAh is a "useless detail", since the Voltage is not given. Presumably it's a single cell Li Ion voltage, as @FreeRide used it - the resulting numbers make sense, but that's just guess work. Giving the mAh for cells could make sense for designing circuits with them. Normaly one has a voltage regulator after the battery. This has some drop, but still (more or less) the same current is flowing. So the designer by this can estimate the energy he has available for his circuitry. If the battery capacity was given in Wh he would first have to calculate with the nominal Voltage Wh backwards to Ah. As the voltage over a discharge of the battery is very "unstable" Ah is much easier to measure and handle as Wh, too. ... Or this comes from something totally diffrrent ... Link to comment Share on other sites More sharing options...
FreeRide Posted November 13, 2018 Share Posted November 13, 2018 9 hours ago, meepmeepmayer said: My brain just hurt a little And the worst part is, I can't even blame you for writing it like this, because that's just consequent to how others do it and therefore for comparing sizes. Everyone is guilty, me included. "2900mAh cells", "3500mAh cells" (well, at least there it saves one from having to use a decimal separator still no excuse) While we're on off topic, why in the devil's name are battery capacities given in Ah instead of Wh? Is current really more important than power in real life considerations? I still don't know the voltage of my phone battery and how much energy actually is in there... All hail SI units! Currently enjoying the thought of my ACM's 4.6MJ battery Yes, sorry; it is sick I know. >why in the devil's name are battery capacities given in Ah instead of Wh? For the same reason the light bulbs were (and still mostly are but getting better) rated in terms of Watts and not Lumens for their Brightness specification. Then with mAh their is always the nice boost from 'bigger is better' 50,000mAh sounds so much better right.... well actually to me 50Ah sounds better as that is what I'm use to, but if your only experience with mAh has been with your phone batteries over the years it sounds so impressive. The serious companies list the Wh capacity, and they may even list it for the different output voltages. The first pack I bought for high output was supposed to deliver 130W, but the high amperage 12V output was not regulated, so the 12V output was not 12V at it's spec'ed 10A output rating so it could never come close to even 120W output. Still it was an interesting little device packed with a lot of batteries and served it's purpose. The biggest problem still with these devices is they never tell you which battery cells they are using, and in fact may use different ones in different units. If they do say, they usually say something like LG cell or Samsung cell, like that is supposed to mean something. They are trying to say they use a battery that won't blowup, but these companies make so many different cells it tells you nothing about the potential performance of the device. Link to comment Share on other sites More sharing options...
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