DC current limiting 42V

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Last seen: 2 days 5 hours ago
Joined: 12/26/2013 - 12:02
Posts: 4
Location: UK
DC current limiting 42V

Hi. I have electric scooter xiaomi m365 which have 42V battery in it.
It does have charging port there- which is used for charging with 42v 1.7A 220v charger.#

I wish to charge my scooter outdoor from hoverboard 42V battery.
If i plug it straight up to charger port- it may go 100A and will melt my cables/burn battery PCB.

How can i limit A from my 42V hoverboard battery to charge a little bit discharged 42V scooter battery throught charging port?

There is no 42V to 42V DC to DC charger anywhere?
Siplest one will be to limit current somehow to 2A, but i can not figure out how.

Robin Dobbie
Last seen: 9 min 33 sec ago
Joined: 04/30/2019 - 12:49
Posts: 966
Location: Texas

I think most DC converters with constant current require a voltage difference. At least the cheap ones I’ve messed with. So maybe a buck converter on the source to bring it down to 28V and then a boost to push it back up to 42V while limiting current to 2A? So 42V at 2A is 84 watts. 84 watts divided by 28V is 3A. My experience is anything over like 2A needs a fan. Again, at least on the cheapies I’ve messed around with.