Specs for actual power use while i2 is charging.

[SF Segway Tours]

We are trying to calculate the electrical power needed to charge our fleet of Segways. We are building a new storage facility and the electrician needs the information to calculate circuit loads.

We have all Segway i2 units – We are storing 22 units to charge at the same time in the new facility.

I'm aware that the units draw a larger amount of power when initial charging and the seem to be on a lower trickle charge as they proceed through the charge cycle.

Anybody have specs for actual power use while charging.

[Civicsman]

I don't have the specifications, but the real-world numbers are easy enough to come by. Every electrical engineer either has or has access to a multimeter, which includes an ammeter. Have your engineer make up a AC charging extension that includes the ammeter. When you place a Seg on charge, you'll read the AC current required. I would take a total of at least 30 samples from different Segs under different conditions, including ambient temperature and battery case temperature. Then use a statistical method to determine +3 standard deviations, which should approximate your worst case. Then add at least 50% margin for the charging circuits alone (apart from building lighting, etc.). Your EE should be able to do all of this in an hour, apart from taking the readings.

[SF Segway Tours]

I don't have the specifications, but the real-world numbers are easy enough to come by. Every electrical engineer either has or has access to a multimeter, which includes an ammeter. Have your engineer make up a AC charging extension that includes the ammeter. When you place a Seg on charge, you'll read the AC current required. I would take a total of at least 30 samples from different Segs under different conditions, including ambient temperature and battery case temperature. Then use a statistical method to determine +3 standard deviations, which should approximate your worst case. Then add at least 50% margin for the charging circuits alone (apart from building lighting, etc.). Your EE should be able to do all of this in an hour, apart from taking the readings.

Specs must be available somewhere without need for an onsite test / calculation. This is an engineer working in house for a Electric contractor bidding on our project. They are looking for tear sheet data similar to what's available for many electric devices. Thanks for the suggestion.

[emrnyc]

There is nothing listed in any of the segway docs
There is the specs of the off board charger:

INPUT100-240 VOLTS AC - 50-60 Hz - 1.4 AMPS 140 WATTS

This should help....

Specs must be available somewhere without need for an onsite test / calculation. This is an engineer working in house for a Electric contractor bidding on our project. They are looking for tear sheet data similar to what's available for many electric devices.

[Civicsman]

There is nothing listed in any of the segway docs
There is the specs of the off board charger:

INPUT100-240 VOLTS AC - 50-60 Hz - 1.4 AMPS 140 WATTS

This should help....

This is useful, as it begins to frame the likely requirement, but does the on-board charger have the same characteristics?

[emrnyc]

To best of my knowledge they should be the same. But I could be wrong.
I checked the service manual and the maintenance and there was no current draw listed. But its a good starting point.....

This is useful, as it begins to frame the likely requirement, but does the on-board charger have the same characteristics?

[Civicsman]

I just searched the forum for "amps", and there's a lot of past discussion, much of it related to using an inverter to charge the Seg batteries.

Bob Kerns says the on-board charger consumes 100 watts, which is consistent with the rating of the off-board charger. Bob knows what he's talking about. You might also send a Private Message to Jason at MTOBATTERY. He should know what a typical charger uses, and the profile of current required during charging.

I doubt that you'll find a "tear sheet" for a PT with that level of detail. If you end up concluding that 140W is the max, then a little math shows that a couple of 20A circuits would be enough. Personally, I'd go with three 15A circuits, properly equipped with breakers.

However, your engineer should provide the necessary advice to keep you safe and be sure you meet electrical code.

Good luck.

[emrnyc]

We have been charging between 15 segs and 6 off board chargers (some times a few more or few less) on a standard circut with out any problems. This was at the hosptital. We just got a new space donated in a basement of an garden apartment, and we've been doing the same with out a problem. I'm not sure if we are on a 15 or 20 amp breaker...
I hope that helps

I just searched the forum for "amps", and there's a lot of past discussion, much of it related to using an inverter to charge the Seg batteries.

Bob Kerns says the on-board charger consumes 100 watts, which is consistent with the rating of the off-board charger. Bob knows what he's talking about. You might also send a Private Message to Jason at MTOBATTERY. He should know what a typical charger uses, and the profile of current required during charging.

I doubt that you'll find a "tear sheet" for a PT with that level of detail. If you end up concluding that 140W is the max, then a little math shows that a couple of 20A circuits would be enough. Personally, I'd go with three 15A circuits, properly equipped with breakers.

However, your engineer should provide the necessary advice to keep you safe and be sure you meet electrical code.

Good luck.

[Bob.Kerns]

I just searched the forum for "amps", and there's a lot of past discussion, much of it related to using an inverter to charge the Seg batteries.

Bob Kerns says the on-board charger consumes 100 watts, which is consistent with the rating of the off-board charger. Bob knows what he's talking about. You might also send a Private Message to Jason at MTOBATTERY. He should know what a typical charger uses, and the profile of current required during charging.

Good luck.

I know what I'm talking about because I took the trouble to measure it. What I don't know, because I can't easily measure it, is the inrush current when you first plug it in, as it charges up the capacitors in the power supply. This would be the absolute maximum current you would see, plugging in a fully-discharged battery.

It is very brief, however. Still, if you plug in all 22 Segways after a hard day, during a power outage, when the power comes back on, you might possibly trip the breaker unless you allow some extra headroom for it.

But unless you're planning to power it with solar cells, you're making this too complicated.

Two 20-amp circuits, GFI protected, would suffice with plenty of room to spare. One would not. But I might go with three circuits, spread around, to give you flexibility about where to plug them in without having so many outlets on each circuit as to let you plug in too many on one circuit!

At 140 W each peak, you can have no more than 12 on each circuit (80% of full capacity). Well, 13, but you're not going to put in a single outlet!

Yes, you could get away with more, but no, you should not design it that way. But if you do two circuits of 12 each, you'll have no room for extra stuff you might want to plug in.

Three circuits will let you put in more total outlets, giving you more flexibility, while staying within that 12 outlets per circuit limit.

Regardless of how the space might be classified, I'd regard it as a garage, and use GFI protection. You'll have people coming in from the rain, in their rain gear, plugging in Segways.

If your building has 3-phase power, I'd want each circuit to be on a different phase for load balancing reasons. These loads will appear and disappear together, more or less.

With two phase, I'd split it between the two phases, putting the extra circuit on the less-loaded side.

There may be subtleties to commercial space I'm not familiar with. I was in college when I last seriously read the US National Electrical Code, and I focused more on the residential stuff. That's not a claim of qualification; that's a disclaimer that there might be something I'm missing. But it should at least give you a general idea.

[team222badbrad]

My watt meter says 109 watts @ .93 amps with the batteries at 3/4 charge.

[Bob.Kerns]

My watt meter says 109 watts @ .93 amps with the batteries at 3/4 charge.

I suspect that's the maximum charging rate, so you'd not see higher at a lower state of charge. You would see a brief spike at first plugin, but most watt-meters won't show you that. I'm not sure how the rating numbers are calculated; whether they take into account that initial spike. From what I have seen with various devices and various ratings, I suspect they do.

I'd use the 140W figure. It would be rather expensive to have the electrician out a second time to add a circuit. Not just for the electrician, but also the business disruption involved. Running three 20A circuits makes it all straightforward.

Your and my observations tend to confirm that it's not higher than 140W.

[emrnyc]

I was moving around a seg that had a console cover on found this:

100-240 VAC 50-60 Hz 2 AMP

So here its from Seg its label!!

C:\Documents and Settings\User\My Documents\My Pictures\2011-05-15_18-18-31_852



We are trying to calculate the electrical power needed to charge our fleet of Segways. We are building a new storage facility and the electrician needs the information to calculate circuit loads.

We have all Segway i2 units – We are storing 22 units to charge at the same time in the new facility.

I'm aware that the units draw a larger amount of power when initial charging and the seem to be on a lower trickle charge as they proceed through the charge cycle.

Anybody have specs for actual power use while charging.

[Bob.Kerns]

I was moving around a seg that had a console cover on found this:

100-240 VAC 50-60 Hz 2 AMP

So here its from Seg its label!!

C:\Documents and Settings\User\My Documents\My Pictures\2011-05-15_18-18-31_852

Unfortunately, not all that informative.

If it's greater than 1A, and they don't give more than one digit, they'd label it 2A.

2A at 240V would be 480W, which is nonsense. Even 2A at 120V is 240W.

I would wager my own money on 3 20A circuits, 12 outlets per, never tripping a breaker, even if you managed to start them at the same moment (as in recovering from a power outage).

But if you want to go for maximum paranoia, 4 20A circuits, 8 outlets per, you can do that.

Unfortunately, measuring (and describing) inrush current is tricky, and I just don't have the time to do it. And very brief inrush surges are not particularly relevant.

But we can look at a typical circuit breaker's data sheet!

Circuit breakers are rated to trip at the rated current -- eventually. A GE DES-012 20A AFCI breaker, (http://www.geindustrial.com/publibrary/checkout/DES-012?TNR=Time%20Current%20Curves|DES-012|generic) with a 100ms inrush current, won't trip at 4x the rated current. Even a 1 second surge, won't trip up to about 3x the rated current.

Circuit breakers work on a combination of thermal (delayed) and magnetic (instant) detection. Above a certain point (depending on conditions) the magnetic trip will trip it fairly quickly, but that's higher than these currents.

Bottom line -- I'd still just go with 3 circuits, 12 outlets per.

The worst that could go wrong is if you plug in all your Segways during a power outage, and you trip the breaker when power comes back on. In that case, plug in half of them, reset the breaker, and go plug in the rest.

But I don't see how that would be possible.

[emrnyc]

Please don't shoot the messenger ....... Just passing along what I found...
lol
Unfortunately, not all that informative.

If it's greater than 1A, and they don't give more than one digit, they'd label it 2A.

2A at 240V would be 480W, which is nonsense. Even 2A at 120V is 240W.

I would wager my own money on 3 20A circuits, 12 outlets per, never tripping a breaker, even if you managed to start them at the same moment (as in recovering from a power outage).

But if you want to go for maximum paranoia, 4 20A circuits, 8 outlets per, you can do that.

Unfortunately, measuring (and describing) inrush current is tricky, and I just don't have the time to do it. And very brief inrush surges are not particularly relevant.

But we can look at a typical circuit breaker's data sheet!

Circuit breakers are rated to trip at the rated current -- eventually. A GE DES-012 20A AFCI breaker, (http://www.geindustrial.com/publibrary/checkout/DES-012?TNR=Time%20Current%20Curves|DES-012|generic) with a 100ms inrush current, won't trip at 4x the rated current. Even a 1 second surge, won't trip up to about 3x the rated current.

Circuit breakers work on a combination of thermal (delayed) and magnetic (instant) detection. Above a certain point (depending on conditions) the magnetic trip will trip it fairly quickly, but that's higher than these currents.

Bottom line -- I'd still just go with 3 circuits, 12 outlets per.

The worst that could go wrong is if you plug in all your Segways during a power outage, and you trip the breaker when power comes back on. In that case, plug in half of them, reset the breaker, and go plug in the rest.

But I don't see how that would be possible.

[Bob.Kerns]

The messenger has nothing to fear, and did a fine job.

[emrnyc]

Thank you....:thumbsup:
The messenger has nothing to fear, and did a fine job.