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Charging a Ninebot One while riding


Rotator

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I usually deplete my battery (240W ninebot one E) rinding for one hour and half. I would like to extend to two hours or more.

I need a few watts more in my battery (+100W I think)

Since I have another batteries (LIPO, LIFEPO4, etc...) at home to use, and a DC-DC converter that I can carry in my backpack...Do you know if anybody sucesfully tried to charge the ninebot while riding?

I think than I can charge the internal battery from an external one with the DC-DC converter working at 63vdc at 1amp, easily (if BMS can handle it).

The ninebots appears to work while charging, but no idea if there is a problem under heavy battery demands (using it in the street).

Any thoughts?

 

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Personally I don't like the idea. DC-DC converters are not usually particularly high efficiency. Can you get one that will not exceed the maximum charge voltage for the onboard battery?

Take a look at: 

 

There are some ideas there, in fact @zlymex's idea of a bulb whilst using a battery of the same nominal voltage as the one in the wheel is probably as useful, lighter and simpler than a DC-DC converter.

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10 hours ago, Rotator said:

I usually deplete my battery (240W ninebot one E) rinding for one hour and half. I would like to extend to two hours or more.

...

I think than I can charge the internal battery from an external one with the DC-DC converter working at 63vdc at 1amp, easily (if BMS can handle it).

You'd need a constant current source up to the about 63 V. So a normal dc-dc converter wont work as charger.

The easiest way to extend the range of a ninebot is to swap batteries once the first is depleted. 

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That's right, you need a CC/CV(constant current/constant voltage) output from the DC-DC just like that of a charger. I bought several such DC-DCs and they are all boost type with max power rating from 600W to 800W. Still, the max output current I can set is 1.5A which is a bit small considering the EUC consume 2A to 3A by average. Even if you can find a buck converters(step down) with CC/CV, the small output current makes it impractical to rider.

The feasible way for a 9b1 to add an external battery pack would therefore be:
---- connect the external battery pack thr charge port when both charged full and leave it connected when riding, or
---- add the external battery pack only when the internal is depleted but thr a current limiting device such as a bulb.

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2 hours ago, zlymex said:

That's right, you need a CC/CV(constant current/constant voltage) output from the DC-DC just like that of a charger. I bought several such DC-DCs and they are all boost type with max power rating from 600W to 800W. Still, the max output current I can set is 1.5A which is a bit small considering the EUC consume 2A to 3A by average. Even if you can find a buck converters(step down) with CC/CV, the small output current makes it impractical to rider.

For @Rotator this would be perfect: He normaly depletes his 240Wh battery within 1,5h - He wants to expand his system by a ~100Wh external battery pack. If he can charge with the 100Wh pack at 1,5 A that would mean with an average Voltage of ~55V (100Wh/1,5A/55V) a discharge time of 1,2 hours. So well within his normal riding time.

As far as i understood it, he has some other LIPO, LiFePo battery packs, which are not 15sXp

2 hours ago, zlymex said:

The feasible way for a 9b1 to add an external battery pack would therefore be:
---- connect the external battery pack thr charge port when both charged full and leave it connected when riding, or

Seems that this works for many riders and also some of the bigger EUC manufacturers deliver their high Wh battery packs configured in this "daisy chain" version.

I do not think that that's a real good idea (

and following post). Since there are no reports around of blown BMS for this configuration it seems to work somehow. My guess would be, that the voltage inversion diode works as a "charge current limiter" - by the forward voltage drop at the diode the external battery pack is providing just a normal current, instead of blowing his full capacity into the second pack...

Which would limit the second battery pack to a "recharge pack" and not a real support for the first pack once the motor wants real power...

So once i would mod my EUC with somehow mounting a second battery pack to it, my choice would be to put (similar) packs really parallel to get the full benefit. And having a second similar pack, i imho would just swap the packs once the first is empty - with a ninebot the changing is just taking the led ring of and then removing 2 screws...

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9 minutes ago, Chriull said:

For @Rotator this would be perfect:

I wouldn't recommend this DC-DC method because
----- you just can't find the right DC-DC anywhere in the world.
----- it is too complicated to implement.

Also, I don't think swap battery pack is a good idea either. It will compromise the reliability.

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1 hour ago, zlymex said:

I wouldn't recommend this DC-DC method because
----- you just can't find the right DC-DC anywhere in the world.
----- it is too complicated to implement.

I assume @Rotatorwanted to reuse his available equipment, which is in this form not possible anyhow.

I personaly also would not put an external battery pack on my EUC while driving - but it seems there are people doing it.

1 hour ago, zlymex said:

Also, I don't think swap battery pack is a good idea either. It will compromise the reliability.

Why? Are the connectors not designed for swapping on a regular basis?

The best, easiest (and most expensive) solution should be, to take an E+ (320Wh), P (340Wh) battery pack or something like the 388Wh pack from 1Rad Werkstatt - which should fit his riding requirements and he just takes the original 240Wh battery pack with him as last reserve...

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I've just bought a spare battery for E+ to be able to double range - expensive option I know but swap out is easy and almost zero chance of related of NB1 failure.  I think when using this option you just need to make sure spare battery is protected (in case or something) whilst carrying or storing to make sure connectors/wires don't get damaged/pinched.  Also I will swap batteries each week (I use my NB1 to commute on a daily basis) to make sure I don't have a battery sitting on a shelf for too long.  Does anyone else here use a spare battery to extend range?

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On 2016/2/11 at 5:31 PM, Chriull said:

I assume @Rotatorwanted to reuse his available equipment, which is in this form not possible anyhow.

I personaly also would not put an external battery pack on my EUC while driving - but it seems there are people doing it.

Why? Are the connectors not designed for swapping on a regular basis?

As we have pointed out, @Rotator's DC-DC is not the right type.

There are a lot of people who enjoy long distance ride and hill ride which consume a lot of Wh, We don't think of other feasible ways except adding external batteries. And I found that the hunger for Wh is not a one step for most people.

There are several reasons why I don't like swap batteries:
1. since you carry the battery with you all the time, why not put them together at start
2. they have to be the same physical size
3. before or after the swap, batteries work alone. While parallel connection work together and redundantly
4. more requirement for cells in all swap pack(because they give out/take in more current) while parallel packs require less.
5. swap takes time, and keep other body waiting in group riding
6. swap at field is not in an idea condition: less time, use only tools you carry thus more chance not to fit properly(screws, wires, absorb/adhesive tape)
7. often swap will wear out the connections and/or screws more quickly. Although looks ugly, manufacturer often apply RTV on connectors which cannot be done when swap
8. swapped battery is difficult to charge
9. more than one swap will make things even worse while more than one external batteries work just fine.

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Thank you everybody for your answers.

First of all:

1.- I know the better option is to have a same kind battery in parallel. Better current throughput and hence, less faceplants probability.

2.-I have a DC-DC step up converter with current limit and voltage constant mode what can be used to charge the EUC. Actually I use it to charge the ninebot from the 12vdc of my car. I configure it at 2amps max. and 63vdc max.

3.-I have easy access to another batteries (different types,  RC lipos to Lifepo4 bicycle battery) with different voltages, from 7V to 48V. Different sizes and capacities. Most of them can work with my DC-DC converter without any problem. Anyway, a small percent of the capacity it will be wasted in the DC-DC conversion, I know.

The doubts I have ...do you think that the battery can handle 1 or 2 amps from the external battery (battery and DC-DC converter, actually) while regenerative charge is working at the same time? This is the only issue that I can see.

I did not know about daisy-chain of some manufacturers in their eucs. Thanks for the link of the KS14 battery configuration.

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12 minutes ago, Rotator said:

The doubts I have ...do you think that the battery can handle 1 or 2 amps from the external battery (battery and DC-DC converter, actually) while regenerative charge is working at the same time? This is the only issue that I can see.

If I understand correctly it is a Ninebot with a 240Wh battery. Ninebots have, I believe, a 15cell, nominally 55V battery. That makes the cells nominally 240/55 Amp hour = 4.36Ah. (Probably 15 pairs of 2180mAh cells in parallel).

These should be good quality cells capable of charging at 1C, I.e. 4.36Amps. 

I don't think regenerative charging plus 1 to 2 amps input charge is going to be a problem unless you aim to regularly go down a very very long steep hill quickly with the battery already close to fully charged.

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4 hours ago, Keith said:

I don't think regenerative charging plus 1 to 2 amps input charge is going to be a problem unless you aim to regularly go down a very very long steep hill quickly with the battery already close to fully charged.

Yes. I think so. Using the ninedroid app, I have seen currents of -8amps when braking in a downhill. One or two amps more must not have a big effect.

Moreover, I can connect the external battery 10 minutes later I begin to ride.

With the Dc-dc converter there is not any problem when the external battery is connected, since works like the original charger. If battery is full then will supply 63v. If empty, will supply 56v or less...I mean the voltage needed to run 1 amp or the current limit I have configured. And if it is partial charged, then any values in between.

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12 hours ago, StreetMeatNYC said:

It's not going to do much for an EUC. It says the AC port only handles up to 65 watts and your Ninebot charger is at least 130 watts if not more, which means the portable battery pack will just shut down from the overload and not charge your EUC. 

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I came accross this video

It is rather lengthy, but you see all those ninebot riders with backpacks, and a cable leading to the charge-port. 

The title of the vid suggests a 100km range ... ( I would like to have that)

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@johrhoj Thanks for the video, I posted a comment there asking what did they use to recharge while riding the bots. At least it's good to know the option is doable, even though I personally doubt I'll use that, if somehow there's an accident or slip happened and the cable still attached to the bot, most likely it will ruin the charging port I think, unless there's a magnetic mod or something that will detach the cable immediately when such accident occurs.

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18 hours ago, Vanquiz said:

@johrhoj Thanks for the video, I posted a comment there asking what did they use to recharge while riding the bots. At least it's good to know the option is doable, even though I personally doubt I'll use that, if somehow there's an accident or slip happened and the cable still attached to the bot, most likely it will ruin the charging port I think, unless there's a magnetic mod or something that will detach the cable immediately when such accident occurs.

Yes. First thing I have thought. I would put another "easy to disconnect" conection near the male charge connector. So if you or your euc fall, the extra pack disconnects from the euc.

Anyway, if you are not lucky and the euc falls, may be the male connector or female port will break, even if the extra pack is disconnected in another part of the wire.

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On 11.2.2016 at 8:40 AM, Chriull said:

...

Seems that this works for many riders and also some of the bigger EUC manufacturers deliver their high Wh battery packs configured in this "daisy chain" version.

I do not think that that's a real good idea (

and following post). Since there are no reports around of blown BMS for this configuration it seems to work somehow....

... Just not reading about it, does not mean that it does not happen. Here is the first report (for me) of a destroyed BMS caused by daisy-chaining the packs:

 

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16 hours ago, Chriull said:

... Just not reading about it, does not mean that it does not happen. Here is the first report (for me) of a destroyed BMS caused by daisy-chaining the packs:

To avoid this risk, you always can put a limit in the current of the charge. About two amps would be safe. It is the same current of the stock ac charger. But if you connect a 15s battery in series in the ninebot one without any protection, and you drain your internal battery too fast, you could be charging it with more current than the allowed by the charging circuit and then it will burn.

With this current limit, the downside is, battery will not charge at the right rate if you drain too fast. So you will have to wait or ride more slowly...

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Perhaps someone with a 3D printer can make oversized battery covers? I would think that you would need to make a custom-shaped battery pack though, that pack appears to be in its own container with a custom connector. At that point you might as well see if you could get just the BMS they use for the Ninebot One and build your own pack from scratch using good 18650 cells.

http://cartsnwheels.com/ninebot-accessories/

 

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I called my local Batteries Plus to see if they would build me a custom battery, and they said the 18650's are too dangerous for them to mess with.  Wimps!  hehe

I'm pulling my E+ apart today to see if there would be some way to modify it to hold TWO batteries internally.  The 3D Printed Wider Battery Covers might be the best way to go.

I'm also going to try moving my motherboard to another angle to see if using the Manual Calibration will allow it to work on it's side or laying flat.  Now that we have that...

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