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]

Originally Posted by 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.

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....

Originally Posted by SF Segway Tours

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.....

Originally Posted by Civicsman

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

Originally Posted by 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.

[Bob.Kerns]

Originally Posted by 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.

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.