Battery Life

[Peter iNova]

Mine has been running lower and lower in its capacity per charge since month three. With a lifetime average urban speed of 5.5 mph and a relatively flat city in which most of my gliding occurs, I'm seeing a decisive, progressive deterioration in performance.

The first six months saw perhaps 3 miles per day use and almost always between glides it remained plugged in. By SegFest 2003, it would lose 10% of a charge when fully charged but unplugged over a weekend.

Now it loses up to 30% of its charge just sitting there for 90 hours. And per-charge milage has dwindled down to the 4-5 mile range. Performance problems seemed to increase after the "safety" software upgrade. My total milage is around only 1000 miles and the replacement cost for new ones seems to indicate a cost per mile over 60 cents at this rate.

Can this be a healthy machine, or is it a single unit "issue?"

-iNova

http://www.glidewalk.com

[wayne]

Hi Peter,

Have you drained your batteries all the way down and charged back up. This seems to help some folks.
You may try this if you haven't.

If the batteries last no longer than that I see a lot of folks selling their Seg as soon as the 1st. set of $600.00 batteries are due.



Seg-On
Wayne

[dhugger]

Some people have had better luck than others with batteries. I can still get about 8 miles with mine if I keep it slow, and I've had my HT for nearly a year (it's probaly been charged about 400 times now). A friend of mine had to replace his after only 7 months. When we'd ride together, I'd be down to 3.5 bars and his machine would be dead. I also ALWAYS leave my HT plugged in when I'm not using it. I've never let it sit for more than a few hours. I've read in numerous places that NiMH batteries can get damaged by letting them sit. Leaving the HT unplugged for the weekend on a regular basis might not be a good idea.

http://segwaychat.com/photos/dhugger/dhugger2.gif

[Gizork]

I had that problem, and on the advice of Segway Tech Support, I now drain the batteries totally every couple of months. It takes a long time. Then, charging them up makes them like new. Try it!

[Ground Loop]

Bummer about the faded batteries, Peter. I have to agree that battery replacement cost is by far the highest cost-of-ownership involved in the Segway. I was worried about electrical consumption, but it's nothing in comparison to those packs.

Has anyone opened a Segway battery pack? (And posted pictures?)

What brand/make/rating are the NiMH cells in the pack? I've seen claims that they are 4.0 Ah cells, and also 4.5 Ah cells. Which is correct (for the HTi)?

[Sal]

I will try and track it down, but I remember seeing a pic of one of the packs opened up... looked to the untrained eye like a TON of AA batteries beside each other.

-Sal


Think Different
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Answers that Matter
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[Ground Loop]

AA size, really? I would have guessed they were more like SubC cells. There are supposedly 60 cells in each pack, in series = 72 volts.

Again, if anyone has a dead/broken pack they'd like to sell, I'd pay just to open one up and have a look around. Then I could ship the cells off to the guy who wanted to make art from them.

What's everyone doing with the old packs anyway? :)

[dhugger]

In the i, there are 60 subCs and in the p, there are 48. pt had some pix on bookofseg of the battery packs from the 'exploaded' view segway that LLC built. The batterie pack shells are vibration welded together, so it'd be hard to open the packs without breaking them. I also wouldn't recomend it, as the 72 1.2v cells in the HT are connected in parallel and can put a few amps at about 86 volts. Unless you wanna void your warranty and potentially get a hefty jolt, I'd leave the batteries alone.

http://segwaychat.com/photos/dhugger/dhugger2.gif

[segwayowner]

i would say that the defencies would have to go with weather and climate. I have found it that way.
Just something else to try....

DES: Segway owner....
it has a nice ring to it

A healthy adult can draw in about 200 to 300 cubic inches (3.3 to 4.9 liters) of air at a single breath, but at rest only about 5% of this volume is used.

Right handed people live, on average, nine years longer than left handed people do.

The average cough comes out of your mouth at 60 miles (24 km) per hour.

If the population of China walked past you in single file, the line would never end because of the rate of reproduction.

The average person spends about 2 years on the phone in a lifetime.

[mrleisure]

quote:Originally posted by Peter iNova

Mine has been running lower and lower in its capacity per charge since month three.


Hey Peter- If you haven't seen it yet, take a look at the battery FAQ I put together at http://www.wingnut.com/segway/ There is useful information in there. Try the conditioning procedure, many swear by it.

I'm curious about what's soon to happen here- at some point in the near future the early adopters should be running into the end of life of their original batteries. This could be thousands of units. It will be interesting to see what kind of actors get into the market for refurbished or rebuilt Segway batteries. At some point the dead batteries should barely be worth the shipping.

I don't think many have thought about the replacement cost of batteries. Assuming you got 20 months out of a set, that's a buck a day in replacement cost. Not really a big deal, but you can anticipate the bitching when that reality sets in. It seems much more significant when you calculate it on a cost per mile basis.

I destroyed my batteries in about 7-8 months. But I'm also the King Kamikaze of Segway Owners and getting the shortest possible life was no real suprise. At the distant other end of the spectrum- PT reported a year of daily use with no degradation in performance. On their last legs, my batteries would go from a hot charge to half drained in under 2 miles.


"In the future, we will all drive standing up"
David Byrne, in 1984

[W9GFO]

quote:Originally posted by Ground Loop



Has anyone opened a Segway battery pack? (And posted pictures?)

What brand/make/rating are the NiMH cells in the pack? I've seen claims that they are 4.0 Ah cells, and also 4.5 Ah cells. Which is correct (for the HTi)?


Yes, I have, but I have not posted pictures. The cells are made by Saft, they are 3000 mah.

Rich H

[tofil]

Segway battery info:

http://www.segway.com/segway/component_details.html#batteries

Saft Battery Info:

http://www.saftbatteries.com/120-Techno/10-10_produit.asp?paramtechno=Nickel+systems&Intitule_Produit=VH

[Ground Loop]

Thanks for the SAFT link tofil! Those are some impressive cells.. 40A continuous discharge current, with 100A peaks..

Looks like there has perhaps been one minor upgrade to the cells 3000->3200mAh since the Segway design.

I wonder how many cells I could fit into the control shaft..

[Mr_Laurenzano]

I was wonderiwng if you rotated the batteries front to back and back to front would there be a differance in the charge? Anyone tryed this?


Find the way. Everything comes full circle.

[Ground Loop]

Are the front and rear packs interchangeable? I thought they were slightly different sizes and could ont be swapped front-to-back.

[Sal]

Hmmmm... Pack rotation... Wonderful idea, I also wonder if that is possible.

-Sal


Think Different
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Answers that Matter
www.lilly.com

[W9GFO]

quote:Originally posted by Ground Loop

Are the front and rear packs interchangeable? I thought they were slightly different sizes and could ont be swapped front-to-back.


Yes, they are identical. It should make no difference. The HT makes performace "decisions" based on the weaker pack.

Rich H

[Peter iNova]

Thanks all. I had been draining my batteries quite low, then recharging without a major benefit. Seg recommended leaning it up against a wall with balance on overnight or over a weekend to drain it all the way and that did the trick. This way it hits its ultimate wall and shuts down. Bracing the wheel is recommended so it doesn't relax to the floor in an awkward collapse.

Followed by a looong recharge.

It feels new. No fast self-discharging now. Where it couldn't go two blocks without showing drain on the top bar, now it goes a mile.

-iNova



http://www.glidewalk.com

[I Glide]

I first rotated my batteries roughly nine months ago at the suggestion of someone at Segway, sorry don’t remember who.

I believe it made a difference though I don’t have any numbers to back it. One of my batteries was finishing the main charge cycle much earlier than the other. At that point my perception was that my range was decreasing. I rotated the batteries and within several charge cycles the completion time of both batteries was noticeably closer, and my range markedly increased. For what it’s worth I believe rotation and cycling have helped my battery condition and range.

Steve

[mzokc]

I checked the batteries today after 13th months of daily operation.

It was the first time I glided around Lake Hefner without pushing!

The 10+ mile glide was completed in one hour with only a few short slowdowns for cross traffic (no signals.) A full discharge about a month ago and gliding at about 10 to 11 mph today made the difference. Calm winds and re-plugging in about 30 minutes before loading the Segway HT into the car helped too!

It's comforting to know the quality that Segway LLC has engineered into our batteries!

Mark

http://www.segwaychat.com/photos/mzokc April 04, 2004