Anybody Here Own a Segway?

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Don

Well-known member
Joined
May 10, 2012
Messages
3,108
Location
Biloxi MS
We were in Nashville to look at a boat we were interested in buying and I checked the Internet for 'Things To Do In Nashville' - Found lots of attractions, museums and the like and about #15 on the list was 'Take a Segway Tour of Nashville' so I got to looking into that and found a 4 hour tour which encompasses several museums

Neither Carolyn or I had ever seen a Segway in person, let alone ever set foot on one. She wasn't for it at all - 'I'll fall off and break my leg' so it took some convincing, but eventually she acquiesced and agreed to give it a try. Watched a 10 minute video, got about 15 minutes of indoor practice before our tour guide took us out on the sidewalks of Nashville. What a blast! Half hour into the tour, she says 'I want one of these!' - I said you know we can't get just one . . . . .

So, we bought a pair. Our first excursion on them was a ten mile ride around Tarpon Springs Florida - We were there to look at another boat. Really wish we had bought these 10 years ago. Anything this much fun must be illegal!

I was a bit surprised to learn that they also incorporate regenerative braking - Range is in excess of 20 miles with batteries which are in good shape

They have tours in most major cities - Go give it a try, but beware . . . . it could get expensive! :lol:

Don
 
Ah, - "my wife made me do it…" :roll:

I guess you'll get your exercise by lifting these things in/out of the car :p - do two fit in an i-MiEV?

You can now add these Segways to the list of your stable of EVs. :)
 
To her credit, in 45 years, Carolyn has never 'made me' do anything that I can think of :p
JoeS said:
I guess you'll get your exercise by lifting these things in/out of the car :p - do two fit in an i-MiEV?
I'll have to check, but I kinda doubt it - They were a tight squeeze in the back of the Mazda Protégé 5 and I *think* it's wider than the iMiEV

I'm thinking about welding up a carrier which fits into the trailer hitch on the Mazda so no lifting required :D

Don
 
We've thought about buying a set for tooling around Phoenix when it's cooler ( a lot cooler! ), still an open decision as the knees have to make it through the ride. :shock:

Whilst googling the topic and electric car in TN, I found this, which I will post into a separate topic: http://shockwavemotors.com/index.html
 
Re: I guess you'll get your exercise by lifting these things in/out of the car :p

I've always wondered if they have a mode to allow you to lay it over as it powers up a ramp, or if its very difficult to push up a ramp by the handlebars, for loading into a vehicle.
 
jray3 said:
I've always wondered if they have a mode to allow you to lay it over as it powers up a ramp, or if its very difficult to push up a ramp by the handlebars, for loading into a vehicle.
It has 4 modes: Off, Standby, Balance and Riderless Balance. In the latter mode you can guide it up a ramp, curb or a set of stairs under it's own power. It's not hard to pull it around by the handlebar when it's off, but it's not particularly easy either, as just like the iMiEV, the wheels are directly connected to the motors all the time - There is no neutral mode, so when you pull it, you're turning the gearboxes and the motors which give it a bit of drag

Don
 
Don said:
Anything this much fun must be illegal!
Unfortunately, they are in a lot of places. The good thing is that they hit the market so long ago that a lot of the craze of banning them died off.

They are tons of fun. I rode one at Snowshoe Resort in Snowshoe, WV. Same deal, a training video followed by practice, then a guided run through the resort and out through the woods.

If the price scares you (and you have decent balance and ankle control), a hover board is quite similar though not nearly as capable and lacks the handlebars.

Congrats on your purchase. Have fun.
 
Don said:
There is no neutral mode, so when you pull it, you're turning the gearboxes and the motors which give it a bit of drag
I read something new today - When it's shutdown and you pull or push it, the regen system is recharging the batteries as you go - Explains why it's a bit harder to pull than just the wheels turning over the motors
PV1 said:
If the price scares you (and you have decent balance and ankle control), a hover board is quite similar though not nearly as capable and lacks the handlebars.
We got a pretty good deal on these. We bought the pair from a couple in Florida who got them from a Disney World surplus auction. One had 850 miles on it, the other 2250 and both of them have pretty good batteries (the expensive part). The 2250 mile machine looks like it will go the advertised 24 miles - After an 11 mile ride, the gauge still showed 6 of the 8 bars remaining. The 850 mile machine had 3 of the 8 bars remaining after 11 miles, so it looks like it will go 15 or 16 miles

We got them cheap enough that I figured even buying two new sets of batteries would still have them about half the cost of new machines, but now it looks like we'll be fine with the batteries they came with, at least for awhile

Don
 
One glaring difference between the Segway and any Lithium powered EV. With the Segway, they recommend that you leave it plugged in 24/7, to keep the batteries fully topped up all the time - This is certainly different from the conventional thinking about the care and feeding of Lithium batteries

A Segway can't be turned completely 'OFF' so it's drawing some small amount of current from the battery pack all the time. You activate the machine using the 'Info-Key' which is a hockey puck looking device powered by it's own internal battery. All of it's communications with the Segway are via Bluetooth, so even when the machine is turned off, the Bluetooth receiver is always powered, waiting on a signal from the Info-Key. If you don't keep the machine plugged into 120 volts all the time, the batteries eventually run down and then they cannot be recharged - The sophisticated BMS and charging protocol doesn't recognize the depleted battery as capable of accepting a charge

I was thinking this must make for pretty short battery longevity and was even investigating some way to install a switch to completely power down the machine so there wouldn't be any need to keep them plugged in - If you eliminated the small drain of the Bluetooth receiver, there would be no need to leave it plugged in all the time. But, when I removed all 4 of the battery packs (two per machine, roughly $900 each new) I found that 3 of my 4 batteries are dated 2008 or older. One 2007 and one 2006 and all 4 of them are in pretty good shape, giving me ranges of 15 miles or more. My laptop battery is plugged in 24/7 too, but I've never had one which still works well after it's 3 or 4 years old

I wonder what the 'secret' is - Maybe they only charge them to 80 or 85%? Each battery pack consists of 92 Lithium AA sized cells in series parallel providing about 75 volts at a little over 5 AH. I have no idea how they are wired into the machine . . . . maybe one battery runs the left wheel motor and one the right side, though I kinda doubt it. They advertise the machine has a 100% back up so that if anything fails while you're riding it, it won't come to an immediate stop and toss you off. The motors even have two distinctly separate windings, so even a motor failure doesn't result in one wheel not functioning

Anyway, it's a different philosophy when it comes to the care and feeding of lithium cells, isn't it?

Don
 
Another thing I learned today - A man in Poland has developed an interface which can read the info from the battery BMS, sorta like canion. He can't read every individual cell, just the 23 groups of 4, but his system gets all sorts of info from the BMS - You can watch them balance at the end of the charge

It's not unusual for Segway lithium battery packs to last 8 or 10 or 12 years or more *if* you leave the machine plugged in 24/7 like they recommend, and that keeps the battery pack full, 24/7. How can this be I wondered? We all know (by now) it's not good to keep a lithium cell sitting at 'full' 24/7 when you're not using it. If you *don't* at least plug them in once every couple months, you run the real risk of destroying an $800 battery. The InfoKey communicates with the machine using a wireless system similar to Bluetooth and that system in the machine is powered on 24/7 - No way to shut it off other than removing the battery from the machine. So if left unplugged long enough it will eventually run one of the batteries dead flat and then it won't accept a recharge

The battery packs (it has two) are 92 cells of 18650 form factor, wired 4P23S. The interface he developed shows the max finishing charge Segway is using is only 3.4 volts!! - Very low for a lithium cell. I guess if you're not overly concerned with maximum range, you can dial the max charge voltage way back and make cells last a long, long time. Range on full packs is about 24 miles

I guess this should have dawned on me sooner - The pack measures only 73.5 VDC and 5.2 AH when fully charged. 73.5 divided by 23 is just 3.2 volts. 5.2 AH from 4 paralleled 18650's is only 1.3 AH per cell - No wonder they last so long

Anyway, we're having lots of fun with these. We pop them in the van and have ridden them all over a dozen cities or so, with more to come. 3 days in Tampa FL, 2 days in Tarpon Springs FL, a day in Apalachicola, 4 days in Gatlinburg TN, 4 days in Natchez MS, 2 days in Vicksburg, a day in New Orleans and a day trip to several more 'local' places. We've added almost 400 miles to the machines since we bought them

Don
 
That voltage range jives much better with LiFePO4 cells rather than Li-NMC. Lithium phosphate batteries are known to last upwards of 10,000 cycles and aren't quite as energy dense as standard lithium ion. 3.6 volts is fully charged for them, with 3.2 being the nominal voltage.
 
Yes, they are a form of Lithium ion phosphate (interestingly, not lithium iron phosphate, or is that just an omission??) and are designed for a maximum 3.7 volt per cel charge. Valence Technologies who builds them for Segway is pretty secretive about their actual composition. Valence's patented 'Saphion Technology' is literally a bullet-proof high energy battery pack specifically designed for the PT's - They're more expensive, but I've never heard of a single one catching fire and they've been around a long time

An interesting video - https://www.youtube.com/watch?v=m2cg4mdN2pU

Don

Edit - Further searches turned up the actual chemistry - LiFeMgPO4, so there is iron involved :D
 
The proper format is Lithium Iron Phosphate. It seems that different people use Lithium Iron Phosphate and Lithium Ion Phosphate interchangeably, but I don't believe that is correct.

You'd be hard pressed to get a LiFePO4 battery to go thermal. The most they do is get warm and puff up. I have two puffed LiFePO4 pouch cells in a pack out of a scooter. I might use the rest as a 12 volt battery for the i-MiEV...whenever I get to that project.

On that note, since the hoverboards of 2015/2016 are quite similar to Segways, the reason the hoverboards had fire issues was primarily because of the lack of a BMS. They have conventional Lithium ion cells. The packs were out of balance and, with no protection, one or more cells would be overcharged and vent, causing thermal runaway. Others had faulty chargers, or even faulty cells in a couple of cases. Overall, though, the ratio of boards sold compared to the ones that caught fire is so low, that there is a better chance of an ICE vehicle catching on fire.
 
Must really 'burn up' Saphion :roll: to have their cells lumped in with the others and endure the severe Lithium battery transportation restrictions now in place worldwide!

Interesting about the steady-state charging voltage, as I had characterized a whole bunch of my Headway LiFePO4 cells a few years back using a PowerLab8 and concluded that the maximum I would want to charge them to was 3.45v.

Still haven't performed my current-sharing experiment of parallelling two different brands of 16S LiFePO4, 14S Li(NMC) (i-MiEV chemistry), and 4S 12v AGM, charging the parallel banks to a maximum of 55.20vdc using a regulated power supply, and seeing how they all share both the charging as well as discharging currents.
 
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