Current drain on the charger is 1.5amps at 12 volts, which works out to .15 amps at 120 volts. You need to discover the duty cycle of the charger, which will vary based on the condition and internal leakage in the battery, plus the drain that's on the car from whatever is running it down for you. For the 'electric bill' problem, let's assume 50% charge time. So when it's on and charging, your unit is drawing about 20 watts, off it's drawing almost none. It will take 50 hours to get to 1000 watts at full duty, or 100 hours at the assumed 50% duty. If your California electric bill looks like mine, the all-in cost is about $.15 for a kilowatt/hour, so for a 720-hour month, your bill will increase a little more than a dollar.

 

LOL! that's good.....(electric bill) I'm paranoid due to my electric bill here in SUNNY CA has been OUT OF CONTROL....

previously mentioned....I have an Interstate MTP-91 & it has been great....I think it just took a hit when I stored my GT @ my Mom's house for a month or so...hopefully the "deep cycle" didn't destroy it....I'll just keep an eye on the maintainer to see the duty cycle....

Is the alarm (locking the door) a big drain?
THANKX

 

You are right...I have never actually timed the cycling of the maintainer. But I can tell you that I do notice the "charged" led lit sometimes and not others.

If I recall the manual correctly, the battery maintainer trickle charges first, then applied a float charge periodically to determine the condition of the battery. If the battery responds to the float charge, then it assumes everything is fine...if it does not, then it reverts to a trickle charge again. Either way, it is "automatic" and designed for battery maintenance...hook it up and let it do it's thing!

After talking with a few RV owners who have similar units, I decided to just leave my maintainer connected all winter...from about mid-november to late april. I just remember to disconnect it before starting the car. Again, I just have mine to avoid the inconvenience of disconnecting the battery for winter storage...and to help prolong the life of the battery. I'd hook it up all the time, if my car was stored in the garage regularly.

I see no reason why you should not leave yours connected when the car is parked. No need to disconnect it when the battery is charged...

Regards,
SteveCo in St. John's

 

very helpful, thanks!
gretz 99