[mathewpriest]

Please consider adding a battery gauge in the next kit. Especially with the current lead acid battery, it would be cool to see what the charge level is to prevent over charging and reducing the battery life.

[Mike]

Excellent suggestion. Thanks. Our intelligent chargers will protect the battery from any over charging situations, but the experience of having charge level indication or "electric power range left in the system" information is something we want to add. We're adding a laptop-style level indicator directly onto the casing of the lithium battery itself, since we're developing that from scratch. For the lead acid packs we're still looking at some different options. We usually try for simple, rugged, low-tech ways to solve problems like this so we can keep the retail price as low as possible and the system will be as tough as possible. What do you think about those solid yellow/black strips that used to be on duracell AA batetries?

[kuzumoto]

That would be great

[Mike]

Yeah, we're looking at different LED handlebar displays and things but my personal choice would be one of those color changing touch strip things. Simple, tough, affordable for everyone.

[LoveMyBike]

Is there a Battery Gauge on the Hill Topper Kit? If not, how do you know when the battery is low and should stop using it, since I assume if you drain the battery too far it will kill it completely to the point it is unchargeable.

[rollinawheelo]

no gauge. you have to make trial runs to find your optimum range. most lead batts can take a little abuse but you should back off the juice as you feel it starting to puke out. charge it up asap. the bike still pedals so you don't get stranded.

[LoveMyBike]

no gauge. you have to make trial runs to find your optimum range. most lead batts can take a little abuse but you should back off the juice as you feel it starting to puke out. charge it up asap. the bike still pedals so you don't get stranded.

Hey Thanks for answering...So I assume since the lead battery is rated for 10 miles or so you should keep an eye on the odometer, if you got one. My bike weighs 45 pounds (plus the 10 pounds the motor kit adds), I weigh 140, so I guess that also affects the mileage. What's your experience of mileage based on bike/rider weight?

[Mike]

Hi MyBike,

I'm about 155 and have about a 25lb Giant Sedona I ride around on and also just a Wal-mart cruiser with one of our kits on it. I get a good 10 miles of assistance on flat ground with high tire pressure. The tire pressure and width is a really big deal in my experience with electric bike kits. Any electric bike will have better performance if the tires are pumped up, and thinner road tires will be more efficient than thicker ones.

All our kits (even the 24'' and 26''ers) come with smoother road tires that we've chosen for this reason.

The controller in our system has a low-voltage shut off so the battery won't be damaged if you run until the motor wont turn. Any chance you get you can (and should) charge the batteries, no matter their level.

What kind of battery gauge would you guys like to see on the kit? It works well without one at all, and we don't want to drive up the retail price or add something that can brake, but if there's s clever, tough, battery indicator solution, maybe like those colored strips that used to be on Duracell batteries, we'd love to get ideas about it!

Thanks for the input,

Mike

[Lhotta]

Hi Mike,

In my opinion you want to keep it simple and forget about any battery gauge. Adding additional components only increases the chances of something else that can fail. Also it will increase your price point.

There isn't a huge mileage range on these kits so keeping track of when your battery is towards the end of its range and needing a charge should be fairly simplistic.

Also, the initial voltage reading you get from a battery can be very different from the nominal voltage under load. So if someone checks their voltage before they go out to ride and it says 24V they may think they are good to go for 10 miles only to find the voltage dramatically drops after just 2 miles and leaves them to pedal the rest of the distance on their own.

Just my 3 cents (inflation ya know!).

** Bill **

[LoveMyBike]

Also it will increase your price point.

Speaking of which, I mentioned this in the Suggestion Forum...if cutting cost and keeping it simple is the name of the game, why not keep the price of the lithium battery kit down to $499 just $100 more than the lead acid kit?

Mike said back in September they were considering a Lithium Battery kit whose battery would be only 3 pounds, about the size of a cellphone and in the $499 range and able to do 10mph for 10 miles on level surface. This would bring the total weight for the kit to 8-9 pounds (5-6 pounds for the motor hub).

For $100 more most people would go for the Lithium and from a visual standpoint it would just rock as a lithium batter and controller that took up less than 3-4" could be easily concealed making the bike kit all the more unique and remarkable. I can see that selling to everyone that wanted a boost of power with out all that setup and installation fuss.

[Mike]

LoveMyBike-- Yes, getting the sweet spot of price, range, and weight is what we're working on. Your great suggestions help guide the development! To keep the forum threads clean, let's keep discussion on the "affordable featherweight lithium" in the thread at: http://www.cleanrepublic.freeforums.org/lithium-batteries-big-or-small-t14.html
_______________________________________
Hey Bill,

Your two points about design complexity and also direct SLA voltage indication issues are right on. Any time you add any feature, you have to consider the fact that some proportion of customers don't want to pay more for it, or even learn about what it is and how it works, no matter how well it's designed and how affordable it is.

It's possible if we added a battery gauge to the SLA kit that people would go gaga and love it, but it's also predictable then that everyone would have to pay more, and we would get more customers who were just confused about the feature because they'd need to learn how to 'use' it. With the SLA batteries and their chemical properties of 'surface charge' you'd need a pretty sophisticated system to show the 'real' level of the 'gas tank' on any kind of logical meter. If we just hooked a simple volt meter up to the battery I think we might get more complaints than compliments for the reason you point out: The gauge would directly show the battery 'level' but non-electrical engineer people would mistake that for some kind of exact metric about how many miles of range they had left, at which point just riding the kit for one or two trips becomes a much more accurate gauge of battery charge, as it is now.

The lithium batteries, however, already come with an incredibly complex on-board Battery Management System (BMS) to closely watch over the lithium cells inside the battery while the charge and discharge. This is needed since the lithium chemistry is much more unstable than SLA chemistry. Since there are already a bunch of electronic whiz-bangs inside the lithium battery, it's much easier for us to add a battery gauge to that one, which is what we've done. It's a 'laptop-style' indicator with 4 LEDs on the battery case itself, so though you have to check inside the fabric bag to check the indicator, it's still easy and quick to do. You can see the four LEDs in the prototype picture below.

Thanks for making those good points,

Mike

[Baz]

A design concept to the Velcro handlebar throttle

I had a thought but don’t worry no brain cells were harmed this design brings forward the concepts of minimalism and integration to existing technology its plausible to work just like the power indicator you see on an Duracell betties so the technology is out they to play around with. The power indicator ends at 20% as its always best to leave that bit extra charge in your battery to prolong its life instead of an indication to 0% and people will run there battery beyond that reserved charge threshold which is bad for the batteries I apologies for the art work but it’s near enough to the Velcro handlebar throttle

[Mike]

Hey Baz, this is great! I really appreciate the 'minimalism' concept. The 'duracell strip' idea could certainly be integrated into the existing velcro Grip Switch strap. No apologies needed. I think the artwork really shows the Grip Switch and the additional concept very well, actually.

Do you have any idea where to get that 'voltage strip' sensor stuff?

Thanks for the input,

Mike

[Baz]

There is a few ways you can do this it's just down to user preference and budget to literate a bit more on the design concept of a power gauge on the handle bar grip hear is a plausible way to integrate the technology keeping minimalism as the main goal You can use white flexible LED strips and overlay your colored designed power gauge template and to regulate each led is down to the voltage regulator that you can build into the BSM but I know nothing about electronics so I have no knowledge in that area

But the cool end of the spectrum is flexible OLED screen ore a custom fit designed LCD display with the preference of versatility so that the user can add mods to the software

[Mike]

Again, very cool idea. Setting aside the voltage/surface-charge/real-life-left-in-battery issue that Bill brought up, and focusing on the user display itself, this nice.

Do you have any links or example pictures of the "flexible LED strips" that you're talking about? Do you mean that paper/fabric stuff that

-Do you know where one can purchase just the fabric itself like the fabric at this link? http://www.lumigram.com/catalog/index.php?language=en

-Is this what you mean by "led strips"? http://www.ledlight.com/flexible-led-light-strip-12-volt-dc.aspx

Mike

[Baz]

Hi thanks for the reply and your applied interest in this area to improve your technology to assist your customers to the best of your knowledge but I have lead you in the wrong direction and its best to keep it all simple simplistic and minimalist with the original concept of the Duracell power level strip. I have no links to provide as I did not look up ore research anything I just had a thought and that’s what image popped in my head.

The second link you provided to the flexible led is correct I looked at this sight www.colorfull-lighting.com as you requested a link hope this helps

Baz

[Mike]

haha. No worries. Believe me, to come up with one good, elegant product requires a hell of a lot of "wrong directions" being explored in the first place.

I just threw in that 'lumigram' link for pure brainstorming purposes. Thanks again for the ideas and concept pics.

Ever onward...

[tfiebig]

Mike,

What's the latest on a battery gauge for SLAs? I noticed that all the posts here are from 2009! Any new developments?

Torsten

[bobauch]

There is a mention of the 4 lights on the LIthium battery, but What do they mean? Looks like 4 is a full charge, 3 less, 2 less yet and 1 your near out.. Is that right? Did 12 miles last night of selective use and still ended with 4 lights, but what does that mean?

[robert1389]

You're correct in your understanding of the four lights and how they're supposed to represent your battery's remaining power reserves. This applies when they function properly. Unfortunately, my Lithum has only one of the four lights that functions, despite a fully charged battery. I still have plenty of power remaining even after an aggressive 12 miles mountain bike trek, so I know the battery itself is fine, just indicator lights themselves that aren't functioning properly. So I disregard, recharge as always, and am good to go.

Bob

[bobauch]

During my battery usage the lights go , 4, 3, 2, 1 then 1 flashing and you are done. With my using it to assist and on flat roads I got 50 miles on my lithium battery.