Motor + inverter set ~350$Battery starting from 250$Charger ~150$Other small parts ~150$
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You can't overheat this cell. It can handle 500A discharge current. And in this project the max current is 30A (only on fast charge).
Most of the electronics are from ebay.
Yes, this cells are very good quality, but also expensive. I do use them also for my E-vehicle setups. I have an electric bike with those cells. I will post an instructable of this bike when i will find some time.
There is a fuse. Thanks.
Manythanks for the suggestion. I do not have an Apple phone, so I did notinvestigate much how to enable fast charge on them, but this upgrade is a “musthave” for apple users. Most android and other simple devices are happy justwith the data pins in short circuit to enable fast charging.I did check the output voltage in some situations and it was quite stable. Thishigh capacity battery can handle very high currents and has a minimum internalresistance so there is only a little voltage drop when under load.About the temperatures, when charging one devise at 2A or even 2 devices (oneper DC step up module) the housing does not get warm at all. When charging 3 or4 devices the housing above the DC modules gets warm, but not too hot, so heatis not a problem at all here.
Reverse voltage on the outputs is not blocked, I will think about it and maybe upgrade it. Thanks for the suggestion. About the fast charge port. It is prottected only with a fuse, so a short circuit there would blow the fuse and that's it, no other damage. I wanted to be able to use this port also for discharging the cell when not in use. Since it is not good to leave lithium batteries fully charged for a long time. Discharging to the "storage" voltage around 3.8V is needed in this case. That's why this port is direct to the cell.
I used lipo because I have a lot of them at home from my rc models. When they become lazy for the models they are perfect for projects like this one. And yes, for now this light only has a low battery alarm, but I am allready planning to add a BMS that will have a low voltage shut off.Regarding over discharge it cannot cause fire, but it damages the cells. So you need to stop using them. If you charge such cells that's what can cause fire.
You can charge this power bank in a little more than 1h with external lithium battery chargers like the ones that are usually used for charging batteries of rc models. But of chourse you can also charge it with any micro usb wall charger. That is gogga take 10h+ depending on the wall charger's output current.
You can charge this power bank in a little more than 1h with external lithium battery chargers like the ones that are usually used for charging batteries of rc models. But I reccomend to charge it a bit slower, so about 2 to 3 h is fine. But of chourse you can also charge it with any micro usb wall charger. That is gonna take 10h+ depending on the wall charger's output current.
Yes, it does.
It depends on your phone's battery capacity and how "empty" it is when you charge it. But it lasted for more than a week for me being camping with no electricity and using my phone quite a lot.
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