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Electric Unicycle Specs sheet


esaj

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esaj, Looking at a 'Dragonman' unicycle quoted battery as a 36v 2.2 Ah battery which Google tells me is + 79.2 Wh but the Chinese supplier says is a 132 Wh!!

http://dragonmen.en.alibaba.com/product/60137843838-800450046/Dragonmen_Hotwheel_self_balancing_unicycle_single_wheel_electric_scooter.html

As a first wheel and at $A350 its quite cheap!! Would would you say?

Looks like a typical generic again. The voltage is misquoted in the specs, it says 60V on the upper part of the page under Quick Details.

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Both my different wheels cam partially charge - I'm not sure how much though.
I used them straight away out of the box just to get a feel for them & then charged them up fully later - I never noticed any issue from doing that.
 

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My new Uniwheel has come partially charged - should I run it down before re charging or fully charge before I use?

The manual doesn't make any comment on this - Sumsung batteries.

Thanks

Li-Ion should have no problem of being used when partially charged, it has no "memory effect" like some other battery-types (well, actually I read an article maybe year or two ago where researchers had found out that Li-Ion actually does have a memory effect, but it's so small that it really doesn't matter). The way Li-ion total capacity lowers is with time (as the battery ages) and usage in general, but it can drop much quicker if stored in elevated temperatures with a higher charge, or if let to discharge too low or charged/discharged above the maximum currents. The wheels have battery warnings that usually prevent you from discharging it too deeply and the normal, original chargers shouldn't ever charge it above recommended currents. (I'm using words like "usually" and "shouldn't" because you can never be sure with generics, but at least the wheels of the "better known" larger manufacturers seem to be safe in that regard).

 See here for more details:

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

http://batteryuniversity.com/learn/article/how_to_store_batteries  (disregard everything that doesn't talk about Li-Ion)

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Not sure if this needs to be shown on the spec sheet but there are a few cheap models that come with <100MWh battery now.

Below 100Wh sounds barely usable (although if it really is MWh = megawatt hours, then that's a entirely different thing, but I think you made a small mistake there, unless the wheels are equipped with their own nuclear power plant ;)). I could just change the typical generic to say that there are also <100Wh models.

A megawatt hour (MWh)  is equal to 1,000 kilowatt hours (KWh).  It is equal to 1,000 kilowatts of electricity used continuously for one hour.  It is about equivalent to the amount of electricity used by about 330 homes during one hour.

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Below 100Wh sounds barely usable (although if it really is MWh = megawatt hours, then that's a entirely different thing, but I think you made a small mistake there, unless the wheels are equipped with their own nuclear power plant ;)). I could just change the typical generic to say that there are also <100Wh models.

Ahem, oops. Well I was still technically correct because they are less than 100MWh :P I believe my model is 88Wh and it has been fine for learning on so far but really not had enougth time on it to notice yet, but I've no doubt I'll be upgrading at this point :rolleyes:

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Ahem, oops. Well I was still technically correct because they are less than 100MWh :P I believe my model is 88Wh and it has been fine so far but really not had enougth time on it to notice yet, but I've no doubt I'll be upgrading at this point :rolleyes:

True, all wheels are below 100MWh, I was just being a smart-ass ;)  And don't know if even smallest nuclear power plants produce output below 100MW, most are probably several hundreds if not thousands of megawatts... :P  But how about a nuclear-powered wheel, anyone? Don't worry, a small amount of radiation won't kill you, at least instantly... ;)

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  • 4 weeks later...

This specs list is so useful it really deserves a bump.

Any way of making it appear at the top of the list, rather than having it sink down when no one has posted on the thread?

Haven't pinned this yet, I don't feel the data is complete yet (probably missing at least several Rockwheels), and probably should at least be double-checked for mistakes...

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Haven't pinned this yet, I don't feel the data is complete yet (probably missing at least several Rockwheels), and probably should at least be double-checked for mistakes...

Yeah, get what you mean about completeness and accuracy but I reckon it's worth pinning anyway, with a few clear caveats.

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  • 3 weeks later...

The chart is extremely useful.  Do you have time to update it. I know theres a few unicycles that come out since the chart was created. Im debating about which cycle i should buy next and this would help.

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The chart is extremely useful.  Do you have time to update it. I know theres a few unicycles that come out since the chart was created. Im debating about which cycle i should buy next and this would help.

Don't trust it blindly, most data hasn't been double-checked in any way ;)  I've been a bit busy with totally non-unicycle -related stuff lately, so haven't gotten around to do much except basic moderating on the forums... I'll try to see if I have the time to dig up more data on newer wheels, but won't make no promises. If you or someone else can provide the specs for new wheels, or corrections to the existing data, I can update them to chart.

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Here is some more data to fix or add  :D  - I own some of the wheels, others I looked up.  I own a Pukka too but don't want to admit it.

 

Airwheel X6 is 16-inch / box shell / no lights / also has a Music version
Airwheel X5 has version that plays music
Airwheel Q6 / 2*14 / 170Wh / 18km / double-circle twin-tire type shell / LED lights / kickstand
Airwheel F3 / donut style shell / 16" tire / 12kg / 17km/h / 170Wh / headlight taillight / smartphone app /

Gotway M0 / battery 260, 340 / shell type slim (there is no box) / geared motor

Inmotion V3 / 2*14 tires / shell type is not a box, you could call it "slim twin-tire shell" as compared to a Q3 which is more boxy though the Q3 doesn't have the gen1 type of box like a Solowheel does (twin tire design practically eliminates the box but are usually wide except the Inmovtion is slim) / integrated hidden trolley handle / bluetooth app

IPS 131 (AKA F400) / claims to have a new 400 battery but I believe they always advertised their battery as 4400mAh which at 60v doesn't that translate to 264Wh battery?  Unless I have the model wrong, the F400 was the first to claim longest range (meaning largest battery) and back then describing the battery in Wh was not common or wasn't standard yet - but if you look closely isn't 4400mAh just two packs of 132Wh?  Imagine back in the day when that was the "longest running" euc!

 

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Updated the Inmotion V3 tire size above - I am surprised when I finally checked the tires that they are 14-inch which is hard to believe because it feels so narrow between the pads.  I'm pretty sure I saw specs a long time ago that said it had 12-inch tires but not so.

The markings on the tires tell the story:  "14 x 1.50 / (40 - 254)"

254 is the standard bead size (?) I've noticed for 14-inch tires

40 is the width of the tire which is pretty narrow compared to maybe 54 as typical

14 x 1.50 is the tire in inches  - again narrow compared to 2.125 typical?

Tire inflation  39 - 65 PSI  (A note - I once saw a chart that for my weight I calculated I should use 75% of the max tire pressure, so that is 58 psi here)

also stamped on the tire is "Inmotion"

 

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  • 1 month later...
On 9/2/2015 at 4:31 PM, esaj said:

I meant you need a BMS to build a custom pack... the ready-made packs of course have their own BMSs already, so pretty much all you need to do is connect them to the mainboard (and maybe solder some connectors on them, if they don't come with the right kind). And yes, you could probably use an existing BMS (assuming it works). Don't know about cradles, as the battery packs get a lot of physical shocks during use on wheels, I guess the welding is the best approach so they don't come off as easily, and don't take too much space, as it's always limited. Maybe they could work though. Typically it looks like the tabs are welded to cells, and the cells are welded/soldered together and shrink-wrapped tightly along with the BMS.

Spot-welding is usually used at least for connecting the tabs to cells, but they could be soldered too (don't know how well they'll hold). It seems most stores have at least some cells available already tabbed (typically Z- and/or U-tabs, in Z, the tabs point to opposite sides of the cells, in U-tabs, both point to same side of the cell), or you can ask them to tab the cells like you want (depending on the store, if they have the machines, and it probably costs extra), but some people have built their own machines. As the cells are heat sensitive, the spot-welding has to be done fast, without heating the cell too much, the "professionals" use spot-welding machines made specifically for battery welding:

Professional-Power-Li-ion-Battery-Weldin

The tabs are then used to connect the batteries together in series (either by soldering or spot-welding), or in case of some BMSs, soldered or welded directly to the BMS:

F4R7D2MG1XBDXKS.LARGE.jpg

The cells in above image are not Li-Ion, but the idea is the same: connect them in series using the tabs.

HTB1j.ZfGVXXXXc1XFXXq6xXFXXXi.jpg?size=1

The above is the kind of BMS with which the cells are connected directly to the BMS with the tabs, no need for separate balancing wires.

(Sorry for the huge images, I just picked up something fast from Google image-search ;))

Also the BMS balancing wires need to be soldered/otherwise connected between the cells:

16Slogo-1.jpg~original

Hope that clears a bit how the batteries are built, I just ordered my custom packs ready-made, as I don't have spot-welding equipment or even a proper soldering iron for that kind of work  ;)  And had I ordered the cells & BMSs myself, the parts alone would have cost about as much as the parts + work done by a professional, who could get the parts cheaper, plus now they've got warranty for any defects.

re the custom packs which can be ordered, is it possible to add that to the existing battery and connect it via parallel? basically what i want here is an added range and i dont mind if the custom packs is located outside the shell.

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4 hours ago, joelren2k said:

re the custom packs which can be ordered, is it possible to add that to the existing battery and connect it via parallel? basically what i want here is an added range and i dont mind if the custom packs is located outside the shell.

If you're going to add the pack outside the wheel, make sure it's properly protected. A physical shock that punctures the cell(s) will most probably cause a fire. There are at least some protected packs that are designed to be connected to the charging port, and they then charge the internal battery while riding, although probably at a slower rate than it's being discharged.

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9 hours ago, esaj said:

If you're going to add the pack outside the wheel, make sure it's properly protected. A physical shock that punctures the cell(s) will most probably cause a fire. There are at least some protected packs that are designed to be connected to the charging port, and they then charge the internal battery while riding, although probably at a slower rate than it's being discharged.

thanks for that protection info yah il do that.  my concern right now if it is possible to add/connect via parallel another batt pack?  whats your opinion?

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13 hours ago, joelren2k said:

thanks for that protection info yah il do that.  my concern right now if it is possible to add/connect via parallel another batt pack?  whats your opinion?

Yes, it's possible to add packs in parallel (I've done so with my custom packs). Before you connect them, make sure they're all at the exact same voltage (like +-0.1V difference at maximum, preferably no difference at all). The reason is that if you connect them in parallel and the voltages are different, the pack(s) with higher charge (higher voltage) will start charging the pack(s) with lower charge (lower voltage), and as there's very little resistance in the batteries themselves, the charging current can be quite large and possibly damage the packs (worst case scenarios: overheating, leaking, fire, explosion).

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11 hours ago, esaj said:

Yes, it's possible to add packs in parallel (I've done so with my custom packs). Before you connect them, make sure they're all at the exact same voltage (like +-0.1V difference at maximum, preferably no difference at all). The reason is that if you connect them in parallel and the voltages are different, the pack(s) with higher charge (higher voltage) will start charging the pack(s) with lower charge (lower voltage), and as there's very little resistance in the batteries themselves, the charging current can be quite large and possibly damage the packs (worst case scenarios: overheating, leaking, fire, explosion).

Is it OK to connect batteries in parallel with the same volts but different watts? For example, say if I connect a 60 V 132Wh (2.2A batteries) pack and 60 V 680Wh (3.2A batteries) pack together, would it be OK? 

 

Also, where can I learn about these things on BMS, C values, volts, wattage, lithium batteries, etc? What website gives examples on how these things work together? Any YouTube links...preferably in English obviously? Lol

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18 minutes ago, Yashaya Yasharahla said:

Is it OK to connect batteries in parallel with the same volts but different watts? For example, say if I connect a 60 V 132Wh (2.2A batteries) pack and 60 V 680Wh (3.2A batteries) pack together, would it be OK? 

AFAIK, this should be ok (at least hobby16 has stated so, and probably others too). Not 100% sure on the implications of doing that, but apparently it should work just fine(?)

Quote

Also, where can I learn about these things on BMS, C values, volts, wattage, lithium batteries, etc? What website gives examples on how these things work together? Any YouTube links...preferably in English obviously? Lol

http://batteryuniversity.com/learn/ has been a good source (although some of the information in the articles is outdated, eg. maximum charge currents in modern cells can be higher etc.) for basic information. Other than that, I've scrounged it up all around the web. There're lots of (scattered) posts and topics here in the forums also.

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10 hours ago, esaj said:

AFAIK, this should be ok (at least hobby16 has stated so, and probably others too). Not 100% sure on the implications of doing that, but apparently it should work just fine(?)

http://batteryuniversity.com/learn/ has been a good source (although some of the information in the articles is outdated, eg. maximum charge currents in modern cells can be higher etc.) for basic information. Other than that, I've scrounged it up all around the web. There're lots of (scattered) posts and topics here in the forums also.

Thanks a lot, Esaj!^^

33 minutes ago, Niko said:

It seems that this is what we are already doing if we put 3 identical cells in parallel: two cells in parallel have double the capacity of a single cell, which are in effect put together in parallel to the third cell.

Can you give me a picture or a diagram showing this? I'm such a visual guy though I might just be dense. This is all very new to me and I want to give it a shot at making my own battery. The LG and Samsung batteries are made here and are cheaper because I live in South Korea~ lol. 

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  • 1 year later...
On 1/3/2016 at 11:35 PM, Yashaya Yasharahla said:

Is it OK to connect batteries in parallel with the same volts but different watts? For example, say if I connect a 60 V 132Wh (2.2A batteries) pack and 60 V 680Wh (3.2A batteries) pack together, would it be OK? 

 

Also, where can I learn about these things on BMS, C values, volts, wattage, lithium batteries, etc? What website gives examples on how these things work together? Any YouTube links...preferably in English obviously? Lol

yes and no.

There are single cell that can store more energy than other cells. If you take two 4.2volt cells with different capacity as they are discharged, the lower capacity cell will start to run out faster. Then the higher capacity cell will be working harder to make up for the lower capacity cell. So it would not be healthy for the higher capacity cell longevity. The higher capacity cell will always be working harder lowering its life expectancy.

Also when charging the lower capacity cell will get overcharged waiting for the higher capacity cell fill up.

If you mix the individual cell types, it need to be engineered so you dont damage them.

Please dont get confused. I am strickly talking about a individual battery cell and not a battery pack.

for battery packs I still think if you are connecting in paralled multiple packs of the same voltage, you still want to use packs made with individual batteries of the same capacity.

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