DC Outlet Battery Booster

I bought an "Auto Starter" that plugs into a car's DC outlet and
supposedly recharges a vehicle's weak battery in 30 minutes. I plan to
use it on my '85 Buick, but was wondering if it would cause any
electical/computer problems if I had to use it on my 2002 CR-V. Who
knows if this type of device is safe or not, since it will send a
charge in the opposite direction than that for which the electrical
system was designed?

 

The direction of the current feed is not going to be a problem. The
first thing you need to worry about on the CR-V is that the power
outlets are ignition switched. This means that the device will not be
able to charge your battery unless the ignition is on (Not sure if "ACC"
will do it or if you have to turn it all that way to "RUN"). I believe
the rear power outlet is wired through a relay and that it can be fairly
easily rigged to work even with the ignition off.

The second thing you have to worry about (for both cars) is how much
current the device is delivering. Honda typically has a 15A fuse on the
lighter socket. If your device is sourcing more than that you have to
worry about the fuse blowing, or better yet, the wiring being fried.
Make sure the device has some way of limiting the current.

Capacities of car batteries are on the order of 50 Ah. You might find
small cars with a 30 Ah battery, and big diesels with 120 Ah batteries.
Going with the manufacturers claim of recharge in 30 minutes and the
current limit of 15A, you could get no more than 7.5 Ah into that
battery in 30 minutes. Hardly a complete recharge, but likely enough to
start a car if your battery is good but partially discharged (from
leaving lights on etc.). You'd probably be better off putting a reminder
chime on the head lights and replacing your battery before it fails.