I recently bought a Honda Odyssey 2.2, imported from Japan. The car is in excellent condition and runs well. The only problem is the battery keeps draining and needs charging weekly. It is not being drained by the radio. Any suggestions please?

A car battery can run down for any of several reasons:

* You accidentally left the lights on or some other accessory that pulls power from the battery even when the ignition key is off.
* The battery is not being recharged while the vehicle is being driven (you have a charging problem)
* There is a key off parasitic electrical drain on the battery because a relay is sticking, a module is not shutting down, or there is a shorted diode in the alternator.
* Your battery is old and will not hold a charge anymore. The battery needs to be replaced.

Which regard to your radio. If you listen to your radio, with the engine off, at a high(ish) volume then your car's original electrical system is put under more pressure than it was designed for. So the battery will go flat relativly quickly.
If you often listen to your music with the engine off then you will have to look into getting a higher rated alternator or a second battery!
Hope this helps

That list of what the reasons are for causing a battery to drain. Leaving anything on radio, lights on the inside can drain it. A battery might need replacing if it won't keep charged while driving. Or it could that it's not being charged during your driving. Is that the Alternator? That what charges your battery during driving. So it should maintain the charge.