CyberEric
CyberEric SuperDork
12/12/24 10:26 a.m.

Hi all, 

My tiny house doesn't have power, and I just got internet installed, so I need to run an extension cord from the garage. It's a distance of about 200 feet. The internet extender is a Calix Gigaspire U4HM. From what I can find online it draws 2 amps.

I am currently running three 14 gauge cords. Is this adequate? It seems to be working so far (installation was yesterday) though it did go out last night for a bit. Do I need a 10 gauge extension cord for that distance?

Thanks!

Stampie
Stampie GRM+ Memberand MegaDork
12/12/24 10:32 a.m.

Using an online calculator I got these results.

14 gauge

Voltage drop: 2.14
Voltage drop percentage: 1.79%
Voltage at the end: 117.86

10 gauge

Voltage drop: 0.83
Voltage drop percentage: 0.70%
Voltage at the end: 119.17

I don't see the change making any real difference.

Stampie
Stampie GRM+ Memberand MegaDork
12/12/24 10:39 a.m.

I just looked up the specs on the Calix Gigaspire U4HM and it's 2 amps at 12v.  That's way different.  My calculations above were 2 amps at 120v.  You shouldn't have an issue at all.  I would set up a small solar panel and battery to power so that I didn't have to worry about the extension cord getting damaged.  a 100 watt panel with one hour of sunlight will power it for 4 hours.  That's if in fact it uses that full 2 amps as speced.  Most devices don't.

mtn
mtn MegaDork
12/12/24 10:39 a.m.

Is it just the single Wi-Fi extender on the cord? Realistically I doubt you'd have any problem with that. But my electrician brother would tell me not to plug an extension cord into another, and certainly not a third one. 
 

If this is a permanent solution, I'd say bite the bullet and run electric to the tiny house. Or at least to an outlet outside it. At 200 feet, you're going to be spending $200-$300 for an extension cord anyway. 

imgon
imgon HalfDork
12/12/24 11:32 a.m.

Extension cords for just that will be fine, not the safest option or the best long term solution but it will work. You may find the extension cords trip the GFI outlet when it rains. Be careful when mowing the lawn.

CyberEric
CyberEric SuperDork
12/12/24 3:53 p.m.

@Stampie, thank you very much for doing the calculations, super helpful! I like the idea of getting a small solar panel set up, but this isn't our house, we're renting from friends and I'm wanting to avoid adding something for a very temporary solution. I do have 2 100w panels on my van and an inverter I could plug it into, but I worry about the 100ah AGM battery in the extreme cold here in NE Missouri. But if you think that's something my solar system in the van could handle, that would be good to know.

@mtn, yep just the wifi extender. Nothing else. We did think about getting a surge protector to prevent damage from lightning strikes, and wondered about charging cell phones/lap tops if we had more plug ins. But we don't need to. Is that safe to add cell phone/computer charging?

I don't think running electricity to the house is an option (see above about being renters), but I appreciate knowing that a 10 gauge cord is that costly.

@imgon, thanks! Good to know about the GFI.

 

brandonsmash
brandonsmash GRM+ Memberand HalfDork
12/12/24 4:15 p.m.

Okay, let's do some math here.

Most implements (but not all - please check) can tolerate a 5% variance in voltage, presuming you have a good power supply. 

It looks like the U4 series draws 36W of power. Not much! 

For a 40W load on a 14ga, 200' cable you're looking at a 2.67v drop. If you have a nominal 120 at the start, that's 117.43 at the end. Almost certainly acceptable, even if a drop of 2.5 is nominal.

Adding additional load - cell phone chargers, etc. - will see a voltage drop greater than you'll probably want. Heaters are right out: That's not going to be safe on a 14ga cord.

 

Additionally, I'm assuming you're just daisy-chaining these cords. If they're running outside, for god's sake please at least bag and tape the connectors. Don't mow over them. Don't leave them in sunlight for months. Don't try to coil them if they're cold or frozen. 

 

Stampie
Stampie GRM+ Memberand MegaDork
12/12/24 4:50 p.m.

In reply to CyberEric :

Just to be clear those first calculations are not correct as I assumed 120v 2a.  Your voltage drop will be much lower.  As far as your solar setup I think it's very doable.  I wouldn't mess with an inverter.  I'd use something like https://www.amazon.com/TPEKKA-Compatible-Connector-Universal-Connectors/dp/B08G4CYHJ2/ and connect it directly to a 12v battery that's hooked to the panels.  If you get full sun then 200 watts might do it for 24 hours depending on how big of a battery you use.  It would be interesting to use a killawatt to see how much draw the router actually has.

brandonsmash
brandonsmash GRM+ Memberand HalfDork
12/12/24 5:48 p.m.

In reply to Stampie :

2A @ 12V = 24W, but what I was finding online showed the wingus as pulling 36W. Granted, 12W by itself isn't much, but I wonder where the difference is - that's 50%! 

Stampie
Stampie GRM+ Memberand MegaDork
12/12/24 6:00 p.m.

In reply to brandonsmash :

I was looking at the u4m manual instead of the u4hm.  Unfortunately they only give the power supply max amperage instead of actual usage in both manuals.  I'd be willing to bet the actual usage is less than either.

EDIT - I racked my head to get some comparison that I knew for sure.  I remembered my Weboost Studio cell booster in Gainesville.  I recently measured it's actual usage at 11 watts.  Looking up it's specs on their website and it says it uses 20 watts.  The power supply says it can use 100-240v at .3a.  If we go for the low end on voltage that's 30 watts minium.  There's always a safety factor on the power supplies but if running off a battery then you don't have to worry about that.  If (big if) the u4hm uses the same safety factor then he's looking at around 13 watts of actual usage.

drsmooth
drsmooth Dork
12/12/24 6:46 p.m.

I am no expert on this subject, but could a better solution possibly be extending the Wi Fi signal in some way from the garage to the tiny home? Failing that, there may be options to run it off DC,  tie into a battery bank either through a inverter or possibly it's own cheap panel and battery. 

bbbbRASS
bbbbRASS Reader
12/12/24 9:17 p.m.

I would think you could use DC power quite well for this. Your AGM battery is fine. They start cars well below freezing. It may in fact be the best option for cold temperatures. You should stick to under 300 watts on that long extension cord, but no cell charger or laptop power block will care about a voltage drop. They smooth that and convert to DC anyways. 

CyberEric
CyberEric SuperDork
12/12/24 9:44 p.m.

This is all good news!

I was more concerned about fires, and lightening strikes, in addition to the extender being damaged somehow by improper voltage. It sounds like that's not a worry. 

@bbbbRASS, two questions/comments in regard to your post. 1. That's good to know about the AGM battery being fine. My battery monitor was saying 0%, but reading 12.8ish volts, so I wasn't sure if it was safe to plug something like a cell phone in. I'm not getting much sun this time of year. The way my setup is, I would need to use the inverter as hardwiring to the AGM is not ideal. 2. Would charging a laptop from the extension cord be pushing the 300w you mention? Just curious. We have a main house with power we can do that at.

@drsmooth, Totally! And that was considered but we didn't end up going that route because there was some concern the distance would negatively impact the wifi inside the tiny house. It would be easy enough to take the extender off the tiny house and plug in at the garage to try it though. It seems to be working pretty well and we have had a hell of a time getting internet to this tiny house, so I don't really want to mess with it right now.

@Stampie, thanks for thinking it through for me! I'm not wanting to do a new solar set up as we may be here for just 6 months, but I could plug into the van's system, but it seems unneccesary given the info ya'll are sharing. 

@brandonsmash, thanks for the recommendation to bag the connectors!

bbbbRASS
bbbbRASS Reader
12/14/24 12:05 p.m.

In reply to CyberEric :

12.8V is basically full for a resting AGM. 
 

your laptop charging block should say the wattage on it, but I would be surprised if it's over 100. 60-80 is more likely. 

CyberEric
CyberEric SuperDork
12/15/24 9:55 p.m.

Yeah, 70 watts according to google. Thanks.

So is there a way to know with the battery monitor when it's unwise to charge? A certain voltage?

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