Hacking Dell Laptops To Use Off-Brand Chargers

Dell, along with many other manufacturers, have begun to implement smart features into their laptop charging circuitry. This leaves the user out of luck if they wish to use an off-brand part, or get caught short when their original charger fails. [Neutrino] was in just such a position, and decided to hack around the problem.

The laptop verifies the identity of the attached charger by a third pin. This communicates with a One-Wire IC embedded in the charger, which reports the charger’s identity when queried by the laptop. When [Neutrino]’s charger broke, an attempt was made to use an off-brand charger, with the third pin hooked up to the original failed unit. This tricked the laptop into charging successfully.

For a more permanent workaround, [Neutrino] harvested the One-Wire IC from inside the original charger, and instead hooked it up inside the laptop, directly to the charge port. Thus, the laptop always thinks a Dell charger is connected when power is applied. There is some risk, in that if the user plugs in a lower-power charger than the original, there could be an overload event, but that’s just the risk inherent in the hack.

It’s a tidy workaround for an annoying problem that is all too common in the post-DRM world. Laptop chargers are often prime candidates for failure too; we’ve seen fixes as creative as repairing a Magsafe with a pistacchio nut before!

[Thanks to Levi for the tip]