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What gauge / amp power cord should I use with my battery charger?

Started by Kmac66, January 15, 2022, 04:03:50 PM

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Kmac66

I need to use an extension cord with my battery charger.
What gauge / amp power cord should I use?
Is 16 gauge too small?

Thanks.

handlebar

Quote from: Kmac66 on January 15, 2022, 04:03:50 PM
I need to use an extension cord with my battery charger.
What gauge / amp power cord should I use?
Is 16 gauge too small?

Thanks.

My charger uses under 2 amps. Sixteen gauge is plenty big enough.


handlebar

Quote from: Kmac66 on January 15, 2022, 08:49:19 PM
Thanks!

Come to think of it, I just got a 12-foot 16-gauge extension cord for charging. It's partly for the convenience of reach and partly to have room to plug in my Kill-o-Watt meter. It tells me three things: how long the battery has been charging, how many watt hours the charger has used, and the wattage at the moment.

I keep a record of voltage, miles, and watt hours. Knowing the voltage when I put the battery on the charger and the watt hours added so far, I can estimate how much longer. Not always charging fully is supposed to extend the life of the battery. I can avoid fully charging by unplugging the charger when I see the wattage taper.

JimInPT

Quote from: Kmac66 on January 15, 2022, 04:03:50 PM
I need to use an extension cord with my battery charger.
What gauge / amp power cord should I use?

The standard Rad charger supplies 2A at a little over 50 volts, so that's about 100 watts, or about the same as a lamp with an incandescent bulb.  In the USA, 100 watts from the wall at 120VAC is less than 1 amp.  I think you can see where I'm going with this; the charger draws very little power compared to what every outlet in the house is capable of delivering, so any extension cord at all will work.

If you're charging in the garage or another location where you'll be walking in the vicinity of the cord and charger, I'd use an outdoor-rated power tool extension cord simply for their physical ruggedness, but you can easily get away with the smaller gauges.

As for being able to determine your battery-charge level and shut it off short of 100%, check out this thread:  https://www.radowners.com/index.php?topic=1001.msg7768#msg7768

peanutbutterpope is in the process of creating his first batch of charger regulators; I'm on the list now and I believe he is still accepting inquiries for potential future production runs.
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

handlebar

Quote from: JimInPT on January 16, 2022, 08:47:32 AM
Quote from: Kmac66 on January 15, 2022, 04:03:50 PM
I need to use an extension cord with my battery charger.
What gauge / amp power cord should I use?

The standard Rad charger supplies 2A at a little over 50 volts, so that's about 100 watts, or about the same as a lamp with an incandescent bulb.  In the USA, 100 watts from the wall at 120VAC is less than 1 amp.  I think you can see where I'm going with this; the charger draws very little power compared to what every outlet in the house is capable of delivering, so any extension cord at all will work.

If you're charging in the garage or another location where you'll be walking in the vicinity of the cord and charger, I'd use an outdoor-rated power tool extension cord simply for their physical ruggedness, but you can easily get away with the smaller gauges.

As for being able to determine your battery-charge level and shut it off short of 100%, check out this thread:  https://www.radowners.com/index.php?topic=1001.msg7768#msg7768

peanutbutterpope is in the process of creating his first batch of charger regulators; I'm on the list now and I believe he is still accepting inquiries for potential future production runs.

To be exact, I read 1.35 amp. I believe it was using 109 watts from 122 volts, which would seem to be 0.89 amp. The difference is power factor, in this case 0.66. I find a plug-in watt meter the best way to see what's happening with many appliances, such as battery chargers. I've used one a lot for ten years. Sometimes I wanted to monitor two things at once, so I bought another one the other day. It's another brand because Amazon had a price spike in Kill-a-Watt.

I think the difference between outdoor and indoor cord is insulation. For example, GPT is interior automotive wire. Outdoors, the insulation doesn't last long.

I bought my newest cords because they are strong with thick insulation and a ground conductor. The indoor rating warns me that they won't stand up to the elements as well as outdoor cords. That's okay: I don't leave my outdoor cords out in the weather, either.

JimInPT

Quote from: handlebar on January 16, 2022, 12:20:00 PMI find a plug-in watt meter the best way to see what's happening with many appliances, such as battery chargers. I've used one a lot for ten years. Sometimes I wanted to monitor two things at once, so I bought another one the other day. It's another brand because Amazon had a price spike in Kill-a-Watt.

I'll second your vote for the Kill-A-Watt; I've used them for well over a decade (most recently for some before/after data when doing major upgrade surgery on my workstation), but too lazy to ever put one on my Rad charger; thanks for the details.

For sort of a semi-permanent Kill-A-Watt with second-by-second historical data collection, logging and website/phone access, this works pretty darn well for a reasonable price: 

https://amzn.to/3JN8IvG

Note that since your power usage data passes through their servers, they make their money by selling that data to others, presumably "anonymously" but who knows.  That has some interesting features, though, such as being able to hook up to many power companies to get their rate data automatically - useful if you're billed differently depending on day of week or time of day.  I got the 4-pack to monitor a fridge, freezer, my workstation and a space heater.
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

DickB

You can use a heavy-duty DC extension cord like this one depending upon where you want the brick.  There will be a slight voltage drop when first charging in Constant Current mode, but at the end of the charge the current drops off considerably and the voltage drop is negligible.

I use a power meter on the DC side to measure what is actually going into the battery, which of course does not include power losses in the charger.


Veggyhed

How do you have that meter hooked up to your battery?

Sent from my Pixel 3a using Tapatalk


DickB

Pretty simple. Cut the DC cord, strip the wires. Identify + and - leads with a voltmeter. Charge end to DC IN, battery end to LOAD. 

handlebar

Quote from: DickB on January 20, 2022, 06:10:39 AM
Pretty simple. Cut the DC cord, strip the wires. Identify + and - leads with a voltmeter. Charge end to DC IN, battery end to LOAD.

I didn't know they made such a device. I'll try to think of where I could use one. It was fairly recently that I learned that there are clamp-on meters that will measure DC amps. I don't know how mine works, but it's mighty handy. Without it, I wouldn't know that my 13 hp mower needs more starting current than my car. (The mower is cranked at a much higher speed, and the automatic compression release is apparently not working.)

DickB

Quote from: handlebar on January 20, 2022, 09:47:53 AM
I didn't know they made such a device. I'll try to think of where I could use one. It was fairly recently that I learned that there are clamp-on meters that will measure DC amps. I don't know how mine works, but it's mighty handy. Without it, I wouldn't know that my 13 hp mower needs more starting current than my car. (The mower is cranked at a much higher speed, and the automatic compression release is apparently not working.)
They use Hall effect devices, which measure the magnetic field created by the current flow.

https://www.fluke.com/en-us/learn/blog/clamps/inside-hall-effect-clamp-meters#:~:text=Its%20purpose%20is%20to%20measure,the%20jaws%20of%20the%20clamp.