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General Category => General Discussion => Topic started by: Gregski on August 30, 2011, 09:49:35 AM

Title: 25 AMP Battery Charger in a 15 AMP Outlet?
Post by: Gregski on August 30, 2011, 09:49:35 AM
I am thinking of buying a 48 volt 25 AMP battery charger that has a standard 110 plug.  What is going to happen when I plug it in to a standard 15 AMP household outlet?  Will it only draw as many AMPs as it can ie 15 or will it trip my breaker every time?
Title: Re: 25 AMP Battery Charger in a 15 AMP Outlet?
Post by: Gregski on September 15, 2011, 09:45:13 AM
so here's what I bought as seen in the eBay pictures, man it works great it charges my four 55 Ah batteries in less than 2 hours, I double checked and my garage EFI outlet is 20 amps saweeet, I was also able to mount it right where the oil cooler went originally on the bike so right in front behind the front wheel/fender

(http://gregandsandy.com/wattana/pics/Charger1.JPG)

(http://gregandsandy.com/wattana/pics/Charger2.JPG)

(http://gregandsandy.com/wattana/pics/Charger3.JPG)

(http://gregandsandy.com/wattana/pics/Charger4.JPG)

(http://gregandsandy.com/wattana/pics/Charger5.JPG)
Title: Re: 25 AMP Battery Charger in a 15 AMP Outlet?
Post by: frodus on September 15, 2011, 09:45:50 PM
48V and 25A is the DC output, not the AC input. Same issue you had with the controller. Don't think of these as "whatever amps go in, must come out" because they both convert power from one form into another. They're electrical transmissions. Talk about everything in power. On chargers you need to convert AC of a high voltage and low current to a lower voltage and different current of DC. With controllers you need to convert High voltage (pack) and low current to varying voltage (from 0-100%) to a varrying current that will either equal the pack, or be more than the pack current.

48VDC x 20Amps DC = 1200Watts. The charger likely has a power factor of about .98 or higher, so we're at 1225VA. Then add maybe 5% for inefficiency. We're at ~1285VA

1285VA / 120VAC = ~10.7Amps AC give or take.

It wouldn't blow it anyway. It's not even close to the 20A limit of your receptacle. If it was a 15A receptacle, you'd have a limit of about 1800VA peak, and 12A continuous, or ~1440VA.