Blinky
08-18-2004, 08:39 PM
Our fourth moderated chat was with Mike Gansler, Product Development Embedded Design Engineer
Date: Wednesday, August 18, 2004
Time: 7:00 - 8:00 pm ET (4:00 - 5:00 pm PT)
Participants: Mike Gansler and the Segway community
Moderated by: John Grohol (Segway.com Webmaster)
The following is a transcript of the chat:
John_Grohol: Hi folks and welcome to Segway’s chat event.
John_Grohol: Tonight’s event is hosted with Mike Gansler, a Embedded Design Engineer
John_Grohol: within Segway’s Product Development team.
John_Grohol: Tonight’s topic is The Care and Feeding of Batteries.
John_Grohol: He will help answer your questions and dispel common myths about how
John_Grohol: to best care for your Segway HT's batteries.
John_Grohol: Mike, why don't you introduce yourself to the crowd and tell everyone a little bit about what you do and are responsible for at Segway?
Mike_Gansler: Hi, and welcome to the chat.
Mike_Gansler: I am a member of the Product Development Team, which
Mike_Gansler: is Doug's Team as most of you know.
Mike_Gansler: I work as a Design Engineer for our embedded systems.
Mike_Gansler: By embedded systems, I'm talking about the electronic hardware and software
Mike_Gansler: that make our product go!
John_Grohol: This chat is moderated. After you type in your question, it is automatically forwarded to
John_Grohol: the moderator(me!) for consideration.
John_Grohol: So fire away and let Mike have your battery questions!
W9GFO: The I series is advertised as 72 volts, yet each battery has two 36 volt outputs. Are the 36v output
Mike_Gansler: The battery is comprised of two groups of cells that provide 36V each.
W9GFO: combined inside the base to make 72v, or was it just easier to call it 72v because each battery has
Mike_Gansler: Go ahead -- finish your question -W9GFO - sorry about jumping the gun.
W9GFO: because each battery has 60 cells?
Mike_Gansler: The battery is made up of 60 cells, split into 2 groups of 30.
Mike_Gansler: That's where the 36V per half comes from.
Mike_Gansler: Operationally, the battery is always used as one 72V unit.
Mike_Gansler: The splitting into two sides is most based on packaging requirements.
GadgetmanKen: can't water seep into the battery casing through the vent hole in high water?
Mike_Gansler: The vent hole is made of a material that allowes gases
Mike_Gansler: past it but not fluids. I'm not the expert on that material
Mike_Gansler: but Ron Reich could tell you more about it than you'd probably
Mike_Gansler: care to know.
Mike_Gansler: If you make it to SegwayFest, hit him up and I'm
Mike_Gansler: sure he'll be glad to talk about it.
KSagal: Range, Range, Range. Any word on longer range batteries?
MagiMike: Mike Theoretically, what would be the range of the new Li batteries?
Mike_Gansler: Ahhh. Lithium...
Mike_Gansler: As Ron alluded to previously, we are working on Lithium batteries.
Mike_Gansler: Testing and development are going well.
Mike_Gansler: And we think we will have a solution that
Mike_Gansler: will satisfy the most demanding customers.
Mike_Gansler: Exact numbers aren't in yet, but I can tell
Mike_Gansler: you that the machine weight will not increase
Mike_Gansler: and that issues with shelf life will be improved,
Mike_Gansler: as well as cold weather performance.
Mike_Gansler: Concerning release date, we are moving
Mike_Gansler: as quickly as possible, but we will not compromise the safety
Mike_Gansler: of our product, nor our standards for quality
Mike_Gansler: before releasing.
John_Grohol: We're chatting tonight with Mike Gansler, an engineer in Segway's Product Development Team on the Care and Feeding of Batteries. Welcome to the chat! We're glad you could make it out tonight and spend some time with us.
Stan671: Would a new battery type (such as Li-Ion) require a software upgrade for the power base?
W9GFO: When new batteries are available, will they work on machines running version 10 and 11 software?
Mike_Gansler: Very good question.
Mike_Gansler: Our new battery programs are designed to be reverse
Mike_Gansler: compatible with only a software upgrade required, so
Mike_Gansler: once you have the upgrade, just bolt 'em on and glide!
KSagal: I have wondered at the potential to have an onboard harness, and spare batteries in one of my 'e' style bags, and be able to double the range by employing an a?b switch. What is your thought?
Mike_Gansler: We don't have any accessories that
Mike_Gansler: offer that sort of feature.
Mike_Gansler: In order to keep our watertight seal it is important that
Mike_Gansler: the batteries be properly mounted to the chassis.
W9GFO: When discharging the HT by leaning against a wall,
W9GFO: how does the Seg determine when the voltage is too low to continue?
Mike_Gansler: Good question. Since the battery level is
Mike_Gansler: very important to your HT, we monitor
Mike_Gansler: it via a number of methods. As you would suspect
Mike_Gansler: we look at the voltage, but we also have a few other
Mike_Gansler: methods of determing the battery's state.
Mike_Gansler: I can't get into further detail, but I can
Mike_Gansler: say that the goal is to make sure that your Segway
Mike_Gansler: always keeps close tabs on the battery level.
Neelix: At what point does adding more cells to the battery packs loose effectiveness due to the increased weight? What is the curve?
Mike_Gansler: Very good question.
Mike_Gansler: Adding cells will always add energy which means more range,
Mike_Gansler: but as you said that comes at a price, and that price is weight.
Mike_Gansler: For an HT, range will not be affected by adding a few
Mike_Gansler: cells. Or at least not appreciably -- remeber that in regard to
Mike_Gansler: a rider's weight, a group of 10 more cells is only 20 oz!
Mike_Gansler: However, if you ride with a lot of starts and stops
Mike_Gansler: or on uneven terrain, those weight increases will start
Mike_Gansler: to degrade your range. I don't have any exact numbers, but the
Mike_Gansler: comparison of cells to total machine + rider weight give a rough
Mike_Gansler: idea of the penalty.
Mike_Gansler: Let me clarify one thing --- in my last comment
Mike_Gansler: when I said "range will not be affected by adding a few cells"
Mike_Gansler: I meant the weight penalty will not be large. Of course, the additional
Mike_Gansler: cells will extend the range.
Mike_Gansler: Regarding the next question.
Mike_Gansler: I don't know what the average age is.
John_Grohol: (of a battery pack when it is delivered.)
Neelix: Will we ever see a "Quck release" for batteries to make changing batteries mid-glide easier? Its a PAIN right now.
Mike_Gansler: Quick release is an interesting topic.
Mike_Gansler: It seems to be one of those things that there are only two
Mike_Gansler: camps on.
Mike_Gansler: There are a lot of important tradeoffs associated with quick release
Mike_Gansler: or batteries with fasteners.
Mike_Gansler: Presently, we believe the best compromise is offered by batteries with fasteners.
Mike_Gansler: It's a tough call, definitely.
Stan671: I appears that if water got past the rectangular gasket around the battery connecter that is could make it into the power base. It this true?
Mike_Gansler: The gasket on the top side of the battery is part of the sealing
Mike_Gansler: system that keeps your HT dry.
W9GFO: During regenerative charging, are the cells charged through the same circuitry as when plugged in - in other words, is each block of ten cells charged independently or in blocks of 30?
Mike_Gansler: Charging is always done on a pack level.
Mike_Gansler: Whether the energy is being provided by the on-board battery charger
Mike_Gansler: or buring reg braking.
Mike_Gansler: The key difference is where the energy is coming from -- the wall or
Mike_Gansler: from the outside!
KSagal: How effective is brake recharging, as in down hill, or pushing the unit while on in or not in balance mode?
Mike_Gansler: Good question.
Mike_Gansler: The exact numbers will depend on a number of conditions,
Mike_Gansler: when you are riding downhill, energy being gained from your altitude loss
Mike_Gansler: is going into a number of things, including wind resistance,
Mike_Gansler: seal drag in the transmissions, losses in the batteries,
Mike_Gansler: etc. All of these things will affect the efficiency, and all of them have
Mike_Gansler: their own dependencies.
Mike_Gansler: Some are speed dependent, some are temperature dependent, etc.
Mike_Gansler: It's going to depend on those conditions and riding style!
John_Grohol: We’re chatting tonight with Mike Gansler, an engineer within Segway’s Product Development Team on the topic of Care and Feeding of Batteries.
W9GFO: Explain "pack level" please.
Mike_Gansler: I'm not sure I understand the question? Do you mean how
Mike_Gansler: full the battery pack is?
John_Grohol: You mentioned how "Charging is always done on a pack level" previously....
Mike_Gansler: Ahah -- I remember.
Mike_Gansler: The questions asked about the
Mike_Gansler: fact that our packs are grouped into 2 halves
Mike_Gansler: of 36V, which are also divided into smaller blocks of cells.
Mike_Gansler: When the HT is operating
Mike_Gansler: all 60 of the cells are connected in series
Mike_Gansler: and charging or discharging is done such that the
Mike_Gansler: same current flows through all of them.
Mike_Gansler: Charging or discharging does not
Mike_Gansler: behave in a manner were groups of cells are
Mike_Gansler: selected separately.
Mike_Gansler: Hopefully that clears that up.
Stan671: After a hard 6.5 mile ride to work, I have to plug in the charger right away so that I get the charge time in before leaving work. Is this bad? Would it be better to wait 1 hour before plugging in?
Mike_Gansler: Great question.
Mike_Gansler: Charging is always most effective when
Mike_Gansler: the packs are cool. By cool
Mike_Gansler: I mean in the 41F to 68F range
Mike_Gansler: we mention in our documentation.
Mike_Gansler: During your ride, the batteries will warm up.
Mike_Gansler: This is normal during use.
Mike_Gansler: Here's a simple rule of thumb -- if they feel
Mike_Gansler: warm to the touch and you have the time,
Mike_Gansler: consider letting them cool a bit. This isn't necessary
Mike_Gansler: but like the Battery Care Booklet says, charging is most
Mike_Gansler: efficient when the packs are cool.
Mike_Gansler: If you have the time, give it a try.
GadgetmanKen: Is the regenerative braking charge picked up by the second set of windings in the motors
Mike_Gansler: Motors are a very cool thing.
Mike_Gansler: Especially because they can be run in both directions --
Mike_Gansler: by both directions, I mean either converting electrical power to mechanical
Mike_Gansler: power or the reverse.
Mike_Gansler: When regen braking is happening, the motors are actually
Mike_Gansler: acting like generators, converting the excess mechanical
Mike_Gansler: power back into electrical power and storing it in the battery!
Stan671: Why two battery packs and not just one big one?
Mike_Gansler: Good question. That touches the topic of our redundant
Mike_Gansler: architecture.
Mike_Gansler: Your HT is designed such that if any problems occur
Mike_Gansler: it can initiate a Safety Shutdown.
Mike_Gansler: By having two battery packs we have redundant systems that
Mike_Gansler: can do this successfully.
Stan671: We know that the batteries have charging logic in them: What percentage of the smarts for the battery charging processs is in the batteries vs in the power base?
Mike_Gansler: Charging of the batteries is largely
Mike_Gansler: taken care of by that batteries themselves. If you've looked
Mike_Gansler: at our website, you can see that the packs have a small circuit
Mike_Gansler: board in them. This board performs the monitoring of the cells during
Mike_Gansler: charging, and communicates with the on-board
Mike_Gansler: charging supply to control the charging process.
John_Grohol: Tonight’s chat event runs until 8:00pm ET (5:00 pm PT). We've got about 15 minutes left.... So get your questions in!
SegwayUtah: Mike, is it generally more efficient, regeneration-wise, to travel quickly down a hill -- or to travel down a hill more lowly? Does riding really slowly require energy instead of producing it?
Mike_Gansler: Good question.
Mike_Gansler: Another way to state this questions
Mike_Gansler: is to ask, at what speed should I ride for optimal range.
Mike_Gansler: "Optimal" is quite a strong word. Mike Martin has an interesting answer
Mike_Gansler: to this question on segway.com in the FAQ section.
Mike_Gansler: When you look at all the possible places energy can be lost
Mike_Gansler: to, the optimal efficiency is achieved at slower speeds. This is because
Mike_Gansler: of the issues I mentioned earlier and the fact that some of the more
Mike_Gansler: important ones are speed dependent. Mike's analysis provides some
Mike_Gansler: good insight into this. I encourage taking a look at it.
Stan671: Are the front and back batteries treated any differently while riding or charging? Is one primary and the other secondary? Would it make any sense to switch them once in a while?
Mike_Gansler: Our front and back battery packs are always
Mike_Gansler: working together sharing the load.
Mike_Gansler: I can't see any benefit to switching them.
SegwayUtah: What are the trade-offs made in letting us quick-charge our batteries? Price? Cycle life?
Mike_Gansler: Quick charging batteries has a number of issues
Mike_Gansler: associated with it. For NiMH cells, charge rate is a strong
Mike_Gansler: factor in heating. The faster the charging rate, the more heat that must
Mike_Gansler: be dissipate to keep the cells cool. This affects how the cells can
Mike_Gansler: be packaged and whether additional cooling would be required.
Mike_Gansler: Also, quick charging implies a larger power supply.
Mike_Gansler: Additional power would mean additional charging power
Mike_Gansler: supply size and weight. As an engineering problem, these raise
Mike_Gansler: compromises that need to be carefully evaluated.
GadgetmanKen: Would thermal blankets or cool pacs (accessories) around the platform or batteries make the charge last longer on glides?
Mike_Gansler: During charging, it is not
Mike_Gansler: a bad idea to have a fan blowing air over the packs.
Mike_Gansler: This is by no means necessary, but the descriptions in
Mike_Gansler: the Battery Care Booklet mention how this can be a help.
Mike_Gansler: During charging, keeping the cells cool will allow the charge
Mike_Gansler: process to operate more efficiently and store more energy in your
Mike_Gansler: packs, and energy is range!
tomamil: In the beginning of the chat, you suggested that active development of a new Lion battery was underway and approaching success. What other power sources are under development, if any?
GadgetmanKen: Have you looked into the new ultra-capacitors as a future battery source?
Mike_Gansler: Ultracapacitors is an interesting topic.
Mike_Gansler: It certainly has relevance for our sort of application.
Mike_Gansler: They can provide short burst of high power which is exactly
Mike_Gansler: the sort of demand an HT can put on the propulsion system.
Mike_Gansler: Presently, we are not using this technology in your
Mike_Gansler: present HT, but we are closely watching it.
MagiMike: So what is the one myth most popular on segchat that just makes you guys at the mother ship roll on the floor laughing?
Mike_Gansler: My favorite is the really old
Mike_Gansler: stuff that talked about hovering platforms
Mike_Gansler: and other Star Wars type stuff.
John_Grohol: Just a reminder, if you haven't downloaded and read it yet, please check out the Battery Care Booklet http://www.segway.com/support/docs/battery_care_booklet.pdf
Stan671: Can you tell us about a frog you have kissed?
Mike_Gansler: Very good question -- obviously you know a lot about us.
Mike_Gansler: Frog kissing is a great time and one of the best aspects
Mike_Gansler: of being part of Segway.
Mike_Gansler: Unfortunately frog kissing is a tight-lipped type of thing. Can't
Mike_Gansler: provide any details, sorry!
Stan671: Mike, thanks for doing this chat with us. We really appreciate it. One more question: When can you do this again?
Mike_Gansler: I'm already scheduled to be helping
Mike_Gansler: out at SegwayFest, specifically to provide Q & A
Mike_Gansler: on batteries and such. Hopefully I can see you there!
John_Grohol: Thank you everyone for joining us tonight for this evening’s chat with Mike Gansler. Thanks, Mike, for agreeing to be our special guest tonight. It was great having you and we appreciate your support. On behalf of Segway, thank you!
http://www.segwaychat.com/photos/Blinky/Blinkyblink.gif http://www.segwaychat.com/photos/Blinky/mrblinky.jpg
Date: Wednesday, August 18, 2004
Time: 7:00 - 8:00 pm ET (4:00 - 5:00 pm PT)
Participants: Mike Gansler and the Segway community
Moderated by: John Grohol (Segway.com Webmaster)
The following is a transcript of the chat:
John_Grohol: Hi folks and welcome to Segway’s chat event.
John_Grohol: Tonight’s event is hosted with Mike Gansler, a Embedded Design Engineer
John_Grohol: within Segway’s Product Development team.
John_Grohol: Tonight’s topic is The Care and Feeding of Batteries.
John_Grohol: He will help answer your questions and dispel common myths about how
John_Grohol: to best care for your Segway HT's batteries.
John_Grohol: Mike, why don't you introduce yourself to the crowd and tell everyone a little bit about what you do and are responsible for at Segway?
Mike_Gansler: Hi, and welcome to the chat.
Mike_Gansler: I am a member of the Product Development Team, which
Mike_Gansler: is Doug's Team as most of you know.
Mike_Gansler: I work as a Design Engineer for our embedded systems.
Mike_Gansler: By embedded systems, I'm talking about the electronic hardware and software
Mike_Gansler: that make our product go!
John_Grohol: This chat is moderated. After you type in your question, it is automatically forwarded to
John_Grohol: the moderator(me!) for consideration.
John_Grohol: So fire away and let Mike have your battery questions!
W9GFO: The I series is advertised as 72 volts, yet each battery has two 36 volt outputs. Are the 36v output
Mike_Gansler: The battery is comprised of two groups of cells that provide 36V each.
W9GFO: combined inside the base to make 72v, or was it just easier to call it 72v because each battery has
Mike_Gansler: Go ahead -- finish your question -W9GFO - sorry about jumping the gun.
W9GFO: because each battery has 60 cells?
Mike_Gansler: The battery is made up of 60 cells, split into 2 groups of 30.
Mike_Gansler: That's where the 36V per half comes from.
Mike_Gansler: Operationally, the battery is always used as one 72V unit.
Mike_Gansler: The splitting into two sides is most based on packaging requirements.
GadgetmanKen: can't water seep into the battery casing through the vent hole in high water?
Mike_Gansler: The vent hole is made of a material that allowes gases
Mike_Gansler: past it but not fluids. I'm not the expert on that material
Mike_Gansler: but Ron Reich could tell you more about it than you'd probably
Mike_Gansler: care to know.
Mike_Gansler: If you make it to SegwayFest, hit him up and I'm
Mike_Gansler: sure he'll be glad to talk about it.
KSagal: Range, Range, Range. Any word on longer range batteries?
MagiMike: Mike Theoretically, what would be the range of the new Li batteries?
Mike_Gansler: Ahhh. Lithium...
Mike_Gansler: As Ron alluded to previously, we are working on Lithium batteries.
Mike_Gansler: Testing and development are going well.
Mike_Gansler: And we think we will have a solution that
Mike_Gansler: will satisfy the most demanding customers.
Mike_Gansler: Exact numbers aren't in yet, but I can tell
Mike_Gansler: you that the machine weight will not increase
Mike_Gansler: and that issues with shelf life will be improved,
Mike_Gansler: as well as cold weather performance.
Mike_Gansler: Concerning release date, we are moving
Mike_Gansler: as quickly as possible, but we will not compromise the safety
Mike_Gansler: of our product, nor our standards for quality
Mike_Gansler: before releasing.
John_Grohol: We're chatting tonight with Mike Gansler, an engineer in Segway's Product Development Team on the Care and Feeding of Batteries. Welcome to the chat! We're glad you could make it out tonight and spend some time with us.
Stan671: Would a new battery type (such as Li-Ion) require a software upgrade for the power base?
W9GFO: When new batteries are available, will they work on machines running version 10 and 11 software?
Mike_Gansler: Very good question.
Mike_Gansler: Our new battery programs are designed to be reverse
Mike_Gansler: compatible with only a software upgrade required, so
Mike_Gansler: once you have the upgrade, just bolt 'em on and glide!
KSagal: I have wondered at the potential to have an onboard harness, and spare batteries in one of my 'e' style bags, and be able to double the range by employing an a?b switch. What is your thought?
Mike_Gansler: We don't have any accessories that
Mike_Gansler: offer that sort of feature.
Mike_Gansler: In order to keep our watertight seal it is important that
Mike_Gansler: the batteries be properly mounted to the chassis.
W9GFO: When discharging the HT by leaning against a wall,
W9GFO: how does the Seg determine when the voltage is too low to continue?
Mike_Gansler: Good question. Since the battery level is
Mike_Gansler: very important to your HT, we monitor
Mike_Gansler: it via a number of methods. As you would suspect
Mike_Gansler: we look at the voltage, but we also have a few other
Mike_Gansler: methods of determing the battery's state.
Mike_Gansler: I can't get into further detail, but I can
Mike_Gansler: say that the goal is to make sure that your Segway
Mike_Gansler: always keeps close tabs on the battery level.
Neelix: At what point does adding more cells to the battery packs loose effectiveness due to the increased weight? What is the curve?
Mike_Gansler: Very good question.
Mike_Gansler: Adding cells will always add energy which means more range,
Mike_Gansler: but as you said that comes at a price, and that price is weight.
Mike_Gansler: For an HT, range will not be affected by adding a few
Mike_Gansler: cells. Or at least not appreciably -- remeber that in regard to
Mike_Gansler: a rider's weight, a group of 10 more cells is only 20 oz!
Mike_Gansler: However, if you ride with a lot of starts and stops
Mike_Gansler: or on uneven terrain, those weight increases will start
Mike_Gansler: to degrade your range. I don't have any exact numbers, but the
Mike_Gansler: comparison of cells to total machine + rider weight give a rough
Mike_Gansler: idea of the penalty.
Mike_Gansler: Let me clarify one thing --- in my last comment
Mike_Gansler: when I said "range will not be affected by adding a few cells"
Mike_Gansler: I meant the weight penalty will not be large. Of course, the additional
Mike_Gansler: cells will extend the range.
Mike_Gansler: Regarding the next question.
Mike_Gansler: I don't know what the average age is.
John_Grohol: (of a battery pack when it is delivered.)
Neelix: Will we ever see a "Quck release" for batteries to make changing batteries mid-glide easier? Its a PAIN right now.
Mike_Gansler: Quick release is an interesting topic.
Mike_Gansler: It seems to be one of those things that there are only two
Mike_Gansler: camps on.
Mike_Gansler: There are a lot of important tradeoffs associated with quick release
Mike_Gansler: or batteries with fasteners.
Mike_Gansler: Presently, we believe the best compromise is offered by batteries with fasteners.
Mike_Gansler: It's a tough call, definitely.
Stan671: I appears that if water got past the rectangular gasket around the battery connecter that is could make it into the power base. It this true?
Mike_Gansler: The gasket on the top side of the battery is part of the sealing
Mike_Gansler: system that keeps your HT dry.
W9GFO: During regenerative charging, are the cells charged through the same circuitry as when plugged in - in other words, is each block of ten cells charged independently or in blocks of 30?
Mike_Gansler: Charging is always done on a pack level.
Mike_Gansler: Whether the energy is being provided by the on-board battery charger
Mike_Gansler: or buring reg braking.
Mike_Gansler: The key difference is where the energy is coming from -- the wall or
Mike_Gansler: from the outside!
KSagal: How effective is brake recharging, as in down hill, or pushing the unit while on in or not in balance mode?
Mike_Gansler: Good question.
Mike_Gansler: The exact numbers will depend on a number of conditions,
Mike_Gansler: when you are riding downhill, energy being gained from your altitude loss
Mike_Gansler: is going into a number of things, including wind resistance,
Mike_Gansler: seal drag in the transmissions, losses in the batteries,
Mike_Gansler: etc. All of these things will affect the efficiency, and all of them have
Mike_Gansler: their own dependencies.
Mike_Gansler: Some are speed dependent, some are temperature dependent, etc.
Mike_Gansler: It's going to depend on those conditions and riding style!
John_Grohol: We’re chatting tonight with Mike Gansler, an engineer within Segway’s Product Development Team on the topic of Care and Feeding of Batteries.
W9GFO: Explain "pack level" please.
Mike_Gansler: I'm not sure I understand the question? Do you mean how
Mike_Gansler: full the battery pack is?
John_Grohol: You mentioned how "Charging is always done on a pack level" previously....
Mike_Gansler: Ahah -- I remember.
Mike_Gansler: The questions asked about the
Mike_Gansler: fact that our packs are grouped into 2 halves
Mike_Gansler: of 36V, which are also divided into smaller blocks of cells.
Mike_Gansler: When the HT is operating
Mike_Gansler: all 60 of the cells are connected in series
Mike_Gansler: and charging or discharging is done such that the
Mike_Gansler: same current flows through all of them.
Mike_Gansler: Charging or discharging does not
Mike_Gansler: behave in a manner were groups of cells are
Mike_Gansler: selected separately.
Mike_Gansler: Hopefully that clears that up.
Stan671: After a hard 6.5 mile ride to work, I have to plug in the charger right away so that I get the charge time in before leaving work. Is this bad? Would it be better to wait 1 hour before plugging in?
Mike_Gansler: Great question.
Mike_Gansler: Charging is always most effective when
Mike_Gansler: the packs are cool. By cool
Mike_Gansler: I mean in the 41F to 68F range
Mike_Gansler: we mention in our documentation.
Mike_Gansler: During your ride, the batteries will warm up.
Mike_Gansler: This is normal during use.
Mike_Gansler: Here's a simple rule of thumb -- if they feel
Mike_Gansler: warm to the touch and you have the time,
Mike_Gansler: consider letting them cool a bit. This isn't necessary
Mike_Gansler: but like the Battery Care Booklet says, charging is most
Mike_Gansler: efficient when the packs are cool.
Mike_Gansler: If you have the time, give it a try.
GadgetmanKen: Is the regenerative braking charge picked up by the second set of windings in the motors
Mike_Gansler: Motors are a very cool thing.
Mike_Gansler: Especially because they can be run in both directions --
Mike_Gansler: by both directions, I mean either converting electrical power to mechanical
Mike_Gansler: power or the reverse.
Mike_Gansler: When regen braking is happening, the motors are actually
Mike_Gansler: acting like generators, converting the excess mechanical
Mike_Gansler: power back into electrical power and storing it in the battery!
Stan671: Why two battery packs and not just one big one?
Mike_Gansler: Good question. That touches the topic of our redundant
Mike_Gansler: architecture.
Mike_Gansler: Your HT is designed such that if any problems occur
Mike_Gansler: it can initiate a Safety Shutdown.
Mike_Gansler: By having two battery packs we have redundant systems that
Mike_Gansler: can do this successfully.
Stan671: We know that the batteries have charging logic in them: What percentage of the smarts for the battery charging processs is in the batteries vs in the power base?
Mike_Gansler: Charging of the batteries is largely
Mike_Gansler: taken care of by that batteries themselves. If you've looked
Mike_Gansler: at our website, you can see that the packs have a small circuit
Mike_Gansler: board in them. This board performs the monitoring of the cells during
Mike_Gansler: charging, and communicates with the on-board
Mike_Gansler: charging supply to control the charging process.
John_Grohol: Tonight’s chat event runs until 8:00pm ET (5:00 pm PT). We've got about 15 minutes left.... So get your questions in!
SegwayUtah: Mike, is it generally more efficient, regeneration-wise, to travel quickly down a hill -- or to travel down a hill more lowly? Does riding really slowly require energy instead of producing it?
Mike_Gansler: Good question.
Mike_Gansler: Another way to state this questions
Mike_Gansler: is to ask, at what speed should I ride for optimal range.
Mike_Gansler: "Optimal" is quite a strong word. Mike Martin has an interesting answer
Mike_Gansler: to this question on segway.com in the FAQ section.
Mike_Gansler: When you look at all the possible places energy can be lost
Mike_Gansler: to, the optimal efficiency is achieved at slower speeds. This is because
Mike_Gansler: of the issues I mentioned earlier and the fact that some of the more
Mike_Gansler: important ones are speed dependent. Mike's analysis provides some
Mike_Gansler: good insight into this. I encourage taking a look at it.
Stan671: Are the front and back batteries treated any differently while riding or charging? Is one primary and the other secondary? Would it make any sense to switch them once in a while?
Mike_Gansler: Our front and back battery packs are always
Mike_Gansler: working together sharing the load.
Mike_Gansler: I can't see any benefit to switching them.
SegwayUtah: What are the trade-offs made in letting us quick-charge our batteries? Price? Cycle life?
Mike_Gansler: Quick charging batteries has a number of issues
Mike_Gansler: associated with it. For NiMH cells, charge rate is a strong
Mike_Gansler: factor in heating. The faster the charging rate, the more heat that must
Mike_Gansler: be dissipate to keep the cells cool. This affects how the cells can
Mike_Gansler: be packaged and whether additional cooling would be required.
Mike_Gansler: Also, quick charging implies a larger power supply.
Mike_Gansler: Additional power would mean additional charging power
Mike_Gansler: supply size and weight. As an engineering problem, these raise
Mike_Gansler: compromises that need to be carefully evaluated.
GadgetmanKen: Would thermal blankets or cool pacs (accessories) around the platform or batteries make the charge last longer on glides?
Mike_Gansler: During charging, it is not
Mike_Gansler: a bad idea to have a fan blowing air over the packs.
Mike_Gansler: This is by no means necessary, but the descriptions in
Mike_Gansler: the Battery Care Booklet mention how this can be a help.
Mike_Gansler: During charging, keeping the cells cool will allow the charge
Mike_Gansler: process to operate more efficiently and store more energy in your
Mike_Gansler: packs, and energy is range!
tomamil: In the beginning of the chat, you suggested that active development of a new Lion battery was underway and approaching success. What other power sources are under development, if any?
GadgetmanKen: Have you looked into the new ultra-capacitors as a future battery source?
Mike_Gansler: Ultracapacitors is an interesting topic.
Mike_Gansler: It certainly has relevance for our sort of application.
Mike_Gansler: They can provide short burst of high power which is exactly
Mike_Gansler: the sort of demand an HT can put on the propulsion system.
Mike_Gansler: Presently, we are not using this technology in your
Mike_Gansler: present HT, but we are closely watching it.
MagiMike: So what is the one myth most popular on segchat that just makes you guys at the mother ship roll on the floor laughing?
Mike_Gansler: My favorite is the really old
Mike_Gansler: stuff that talked about hovering platforms
Mike_Gansler: and other Star Wars type stuff.
John_Grohol: Just a reminder, if you haven't downloaded and read it yet, please check out the Battery Care Booklet http://www.segway.com/support/docs/battery_care_booklet.pdf
Stan671: Can you tell us about a frog you have kissed?
Mike_Gansler: Very good question -- obviously you know a lot about us.
Mike_Gansler: Frog kissing is a great time and one of the best aspects
Mike_Gansler: of being part of Segway.
Mike_Gansler: Unfortunately frog kissing is a tight-lipped type of thing. Can't
Mike_Gansler: provide any details, sorry!
Stan671: Mike, thanks for doing this chat with us. We really appreciate it. One more question: When can you do this again?
Mike_Gansler: I'm already scheduled to be helping
Mike_Gansler: out at SegwayFest, specifically to provide Q & A
Mike_Gansler: on batteries and such. Hopefully I can see you there!
John_Grohol: Thank you everyone for joining us tonight for this evening’s chat with Mike Gansler. Thanks, Mike, for agreeing to be our special guest tonight. It was great having you and we appreciate your support. On behalf of Segway, thank you!
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