Charging phone via e-bike battery


I’m in need of a power bank for charging things like my phone when camping. I have a battery from my e-bike that is 52V 35A that I would like to use for this project so I need to get it to a USB A 5v output. Does anyone know of a step down converter that would work with these ratings? or any other way to accomplish this.


Battery Specs:

Battery Output Port


Thank you for contacting DigiKey’s Tech Forum, we are working on this and will get back to you as soon as we can.

Thank you


There are a variety of converters available which do ~48-ish to 5v. Very few however, which are designed as USB charging sources. Protections and protocols attach to the USB charging spec which are not prudent to ignore.

One may wish to consider using a 12V converter, followed by a proper USB charger of the common automotive type. At cost of some efficiency, one would have both conventions available, and a reduced risk of damage to USB devices.

Note that a battery of the sort mentioned is not a thing to be trifled with; connections should be fused properly, and protection against over-discharge ensured.

Please note also that virtually all of the popular cordless power tool brands offer USB charging devices for their battery ecosystems. While a DIY solution may seem appealing, it’s very difficult to compete with mass manufacturing in terms of cost and reliability if one’s time is valued.

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