midnightcheese
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- May 6, 2016
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Is there a way to charge a Macbook using my 48v battery on my bike. DC to DC voltage step down? Or perhaps an inverter?
Thanks,
J.
Thanks,
J.
-
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Charging laptop using bike battery?
- Thread starter midnightcheese
- Start date
flippy
1 MW
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- Aug 12, 2015
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- 2,351
No. Macbooks have DRM built in their charger. Without that signal the laptop refuses to accept any power.
There is a getto way of getting around the charge protection but that entails breaking any warranty and hacking the logic board and have a small lead coming out of the laptop as a secondary charge port.
You can also use a 220v inverter but those are usually 12v, 48v is more high power UPS you find in server racks.
Those cheap inverters you can buy at car stores do not play nice with switchmode power supplies. It will either not work at all or you will kill them in a short while as they do not put out a true sinewave. So you het massive losses (50% or more) and it will kill your charger and laptop.
There is a getto way of getting around the charge protection but that entails breaking any warranty and hacking the logic board and have a small lead coming out of the laptop as a secondary charge port.
You can also use a 220v inverter but those are usually 12v, 48v is more high power UPS you find in server racks.
Those cheap inverters you can buy at car stores do not play nice with switchmode power supplies. It will either not work at all or you will kill them in a short while as they do not put out a true sinewave. So you het massive losses (50% or more) and it will kill your charger and laptop.
I use a cigarette car charger for my laptop in the camper.
I use a lipo hobby charger to bring down the 24v pack to float charge my 12v system and use the 12v cigarette charger to run the laptop.
Im sure it could be simpler but its what I have available right now.
I use a lipo hobby charger to bring down the 24v pack to float charge my 12v system and use the 12v cigarette charger to run the laptop.
Im sure it could be simpler but its what I have available right now.
midnightcheese
1 µW
- Joined
- May 6, 2016
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Sounds like very tricky business. Thanks for the replies.
Dunno about the macbook, but a number of laptop PSUs will run off DC, sometimes as low as 40-45V, as long as they are "started" at a higher voltage from 50-60V.
So you could try simply connecting wires from your bike's battery to the ac-input prongs on your charger's wall cord, and see if it will then charge the macbook--but I would do this only when the macbook is powered off, because the power will only be flowing thru half of the diodes to input into the PSU, and so drawing the full rated power of the PSU could damage them if they're not overspec'd for that much current.
Sometimes a PSU will only work on DC in one polarity (odd for an AC device, but I've had several like this).
Sometimes it won't work on DC at all, regardless of voltage.
So you could try simply connecting wires from your bike's battery to the ac-input prongs on your charger's wall cord, and see if it will then charge the macbook--but I would do this only when the macbook is powered off, because the power will only be flowing thru half of the diodes to input into the PSU, and so drawing the full rated power of the PSU could damage them if they're not overspec'd for that much current.
Sometimes a PSU will only work on DC in one polarity (odd for an AC device, but I've had several like this).
Sometimes it won't work on DC at all, regardless of voltage.
