Jump to content

Recommended Posts

Posted (edited)

I'm a believer that a backpack battery is an attractive solution to "more range," because you can:

  1. Keep the wheel you have (save money vs buying a new 2500wh+ wheel)
  2. Keep the wheel light (easier to lift; ride & handling differences)
  3. Use the backpack only when you need it (option to ride wheel-only, or extra-range, depending on your mood)

This is especially relevant with the emergence of the small-battery suspension wheels (S18, V11). If you want a 40+ mile all terrain ride without charging stops, an auxiliary battery is needed.

If you're already doing it, please reply with a summary of your setup!
(Do you like it? Pros and cons? What pack is it? How do you connect it? How do you recharge it?)

 

ACtC-3eEgeKp8N4wopofE2TLr8m9U2jxQRaOnvLi

Some clarifications on methods:

  • Parallel connection: ("Vamp-and-ride" is the futuremotion jargon...)
    Using an auxiliary pack that has the same system voltage as the wheel.
    The external pack voltage (state of charge) must match the wheel voltage, before connecting the external pack. Failure to match voltage properly will damage the packs or blow fuses.
    A high-current input connector must be added to the EUC. (Typically the charging port is not sufficient.)
    The external pack must remain connected to the EUC for the entire ride, and will deplete at the same rate as the battery in the EUC.
     
  • Charge-and-ride:
    Using an auxiliary pack that has a current-limited output voltage, the same as the output from an AC charger.
    The auxiliary battery pack can be of any voltage, but needs extra electronics to produce the current-limited output voltage that is correct for the EUC.
    The original charging port of the EUC can be used. (Relocated and break-away-style connectors are sometimes added.)
    The auxiliary pack can be removed and reconnected at any time, including during a ride. The auxiliary pack will typically be depleted before the battery in the EUC - an additional auxiliary pack could be swapped in at any time to extend range even further.

The KS-Power is a charge-and-ride system, for example.

Edited by RagingGrandpa

Share this post


Link to post
Share on other sites
Posted (edited)

With my MSuperX, I used sometimes (in a back pack) the batteries of my previous Rockwheel GT16, as an external battery for it.

I plan to use it too as well with my next wheel, a soon coming KS-S18, when necessary...

Edited by sbouju

Share this post


Link to post
Share on other sites
4 minutes ago, RagingGrandpa said:

 

4 minutes ago, RagingGrandpa said:

I think @sbouju uses parallel connection?

Right, I use it exactly as described above.

Share this post


Link to post
Share on other sites

Using the charging port with an external battery/charger should be done only near the end of the internal battery charge so that your braking isn’t affected. 
 

This type of hook up would be great to get maybe 25% more range so that the size and weight wouldn’t be an issue and carried as way to ride home instead of walking when you suddenly realize you played too long. 

Share this post


Link to post
Share on other sites

I used to use one for my hoverboard and it was a little different than both of those suggestions. In addition to the charge port I added a XT 60 connection. I made a y cable and had a switch that would disconnect the internal battery. When my battery was low or almost depleted I switched over to the auxiliary backpack battery. 

Share this post


Link to post
Share on other sites
Posted (edited)
3 hours ago, Globewheel said:

I used to use one for my hoverboard and it was a little different than both of those suggestions. In addition to the charge port I added a XT 60 connection. I made a y cable and had a switch that would disconnect the internal battery. When my battery was low or almost depleted I switched over to the auxiliary backpack battery. 

Yup. Bypassing the EUC's pack is very risky- if your backpack cable pulls loose, instant crash. I've ridden a onewheel this way, but only at low speeds on easy surfaces. Fast offroad EUC riding... risk.

 

5 hours ago, Hal Farrenkopf said:

Using the charging port with an external battery/charger should be done only near the end of the internal battery charge so that your braking isn’t affected. 

I think Charge&Ride is only the same risk as riding at 100% SOC. The usual guidelines apply- don't descend a mountain if you're at 100%.

I average a 1kW discharge rate with my MSX while riding. It's difficult to envision a 1kW-output C&R backpack (excessive heat dissipation), so while underway I still expect a slowly dropping SOC for both packs.

I appreciate the flexibility of being able to use a backpack at the beginning of a ride, depleting it, then leaving it in a parked car and continuing the ride. And similarly, picking it up halfway through a ride. Both are possible with Charge&Ride systems.

Edited by RagingGrandpa

Share this post


Link to post
Share on other sites
Posted (edited)

It has been a long time since I visited this forum. Then I come here and see someone talking about the backpack battery. What a co-incident ! I was the guy who did that power regulator experiment. It was like ages ago.

I am 100% for the charge&ride system. It's safer and flexible. All the parts are cheap and easily DIY. You can reuse batteries from other toys: hoverboards, e-bikes, e-scooters... Plus, no one can ride EUC for hours without taking a break. So whenever you stop for lunch or scenery, it's perfect time to recharge.

TBO, once I had made myself an external battery pack, I never found an occasion I actually needed it. A simple wall charger was much more handy and easier to solve the battery charge problem. Since I owned another 840wh EUC, its range was never a problem for me. So my advice is that: think careful about what you actually need. Do you really need the extended range? The battery pack is heavy and will become uncomfortable after long hours of riding.

Also a friendly reminder that, please don't ride-while-charge. My old EUC board now is bad probably due to that.

Edited by Philip W

Share this post


Link to post
Share on other sites
15 hours ago, Philip W said:

I never found an occasion I actually needed it.

The use-case I'm interested in is staying compatible with group rides when the other riders have 2000wh+. Being the low-capacity guy in a group just sucks, but I love my wheel and don't want another one.

15 hours ago, Philip W said:

please don't ride-while-charge. My old EUC board now is bad probably due to that.

Oh really?

Do you know if the charging input goes through your board, with your old EUC?
Gotway does not, so the only possible harm would be exposing the pack to increased ripple. And there's already severe ripple coming from the ESC, so it's hard to imagine the DC-DC making it much worse...
 

On 8/11/2020 at 2:20 PM, RagingGrandpa said:

please reply with a summary of your setup!
(Do you like it? Pros and cons? What pack is it? How do you connect it? How do you recharge it?)

Nobody else?

Share this post


Link to post
Share on other sites
5 hours ago, RagingGrandpa said:

Do you know if the charging input goes through your board, with your old EUC?

No, the charge go directly to the battery pack. That's why I think it should be OK to charge-while-riding.

Now the board of that EUC is extremely sensitive to voltage. Any time it drops below 58v, the board will shut down and refuse to work. Being not good with electronics, so I have no idea why the board behave this way. The only thing I can think of is that I had done plenty of charge-while-riding on the old EUC. But of course, it can be just the board goes bad by other methods.

I did examine the board, but don't see any blown capacitors or burnt resistors. Yeah, no idea what went wrong. Luckily I still have my other EUC.

Share this post


Link to post
Share on other sites

I think I am contradicting myself, so here I want to clarify it.

I said "I never found the occasion to use the battery pack". It's actually referring to the new wheel. Once I had it, the extra battery pack became a burden.

Yet when the old wheel was still running fine, I did connect it to my battery pack all the time just for the sake of it. The external battery pack did give me longer range and more flexibility in choosing a route.

But for the new wheel, I will only bring a 6A charger with me, and monitor the voltage along the way. Usually I will find a power plug along the way, and I can charge the wheel back to full.

In RangingGrandpa's case, if you need to catch up with other long-rangers, you probably has to do the charging-while-riding thing. Good luck! Also I hope you can find a way to put the external battery on top of the EUC. Carrying them in a backpack is quite stressful after an hour or two.

Share this post


Link to post
Share on other sites
Posted (edited)

I have been swapping batteries on my Ninebot E+ for three years. I have carried as many as five spare packs with me on long trips of up to 50 miles. I typically carry 1-2 spares at all times. It takes less 1 minute to swap the battery, and then I am on my way again. The Ninebot One is the only wheel that can be easily modded to do this. Of course this is an older, slower wheel with a small battery (320-340wh), but it still has its uses.
 

I think that the S18 would be awesome if the battery compartment were easily accessible and could be modded in a similar way. Personally I would not want to carry more than one 1000wh spare in my backpack, though.

 

Edited by litewave

Share this post


Link to post
Share on other sites
12 hours ago, litewave said:

I have been swapping batteries on my Ninebot E+ for three years. I have carried as many as five spare packs with me on long trips of up to 50 miles. I typically carry 1-2 spares at all times. 

 

But why would you want to ride the NB1E+ for 50 miles going that SLLLLOOOOWWWWWWW?

lol

Share this post


Link to post
Share on other sites
2 minutes ago, Hal Farrenkopf said:

But why would you want to ride the NB1E+ for 50 miles going that SLLLLOOOOWWWWWWW?

lol

Speed is relative. The E+ can be hacked to go up to 20mph, which is fast enough for trails and sidewalks. I don't ride among traffic very often, which is more risk than benefit. If I lived in NYC or some parts of Europe then I would reconsider. If in a hurry to get from point A to point B,  I drive an automobile with a 5-star crash rating that gets 55mpg.

 

Share this post


Link to post
Share on other sites

I have done exactly what ragingGranpa states above. I have a mten3 that I bought because it fits in the under trunk compartment in my tesla. I originally bought the mten3 to go places when the car is charging at a supercharger Which can be several miles from anyplace good and charging can take a hour or 2. For this purpose mten3 range (512wh) is fine on its own but I also do Bike trail riding For long stretches and while my wheel will go 23 miles or so, that means I can only go 11 or so miles before I have to turn back. I wanted Longer range so I decided to use a parallel Back powerpack. Like ragingGampa stated. I started looking on eBay. I wanted a pack that was the same voltage (no Solar converters). I settled on a green works gl900 which is a 100 cell pack with 5 cells in parallel per s or 900wh. Mine was 200.00 and missing the mower adapter And charger. The conversion was - I removed the oem plug. Unsoldered the wires from that oem plug and made a cable with a 90degree mic 4 pin connector, added a mic connector to the gl900 (so I can charge with the oem GotWay charger), I had to bypass the bms on the Negative power out. I did use the gl900 bms for charging. I run 2 gotway chargers in parallel (3a) and the pack chargers in a few hours. I figure I could charge The gl900 at 8a if needed But I’ve never needed too.

on the mten 3 I ran an extra two wires to the Charging ports unused pins so I don’t run the pack through the Oem charger wires. The 2 new wires I soldered to the nt90 connector on the battery side (easiest place to do it) My connecting cable is a quick disconnect if I fall off the wheel for any reason the cable doesn’t get tangled (never fallen off this wheel) 

this gives me between 70-80miles of range on this little wheel. The pack weighs 14lb, this was a huge issue the first time I rode with it (30 miles non stop) as my shoulders were not used to it and my balance was much further back. The second ride (44 miles non stop) I didn’t notice the pack at all. My feet get stabbing pains (like the feet falling asleep) but I get this with or without the pack I’m shooting for 55 miles next ride if my feet will let me. The charge level was 49% or 74.6v on the 44 mile ride. I’ve been using this setup for 3 weeks now

parts- pack 200.00,  90deg 4pin mic connector 5.00, 6 foot electric extension cable 2.00, RC motor silicone wire 2’ 6.00, 4pin mic Connector charger connector on pack 5.00, Shrink wrap solder etc 3.00. about 2 hours labor to make it and convert everything. I have pics but I don’t know how to post them

the only problem I can’t solve is the wheel chatters under acceleration above 16 mph, I can fight through it but it is a pain. The chatter is worse when the pack/wheel are at full charge. If anyone knows why the mten3 wheel chatters with the pack connected please let me know, my only thought is the oem pack only has 2 batteries per s and the pack has 5 so maybe the amp output differences between the 2 causes pulses on the gotway controller.

 

I did try carrying a charger with me at first and while it worked I found I was just standing around for an hour while only getting a 30% charge in that hour at 3 amps. 

As a side note my mten3 is not my only experience with euc. I do have a modded ninebot c+ thats modded to 20mph that I use for training others (my first wheel) and a Mcm5 that I only use off-road or yak rustling as it has a bmx nobby Tire.. I am a new Ridder with only 3 months experience. 

 

Spoiler

 

Share this post


Link to post
Share on other sites
Posted (edited)
On 8/19/2020 at 12:59 AM, Azzias said:

green works gl900

Ah, we're brothers!

SmRUdfs1oLId8Ys9VLhWiOrF8IWZKUdIBlCTsJQs

(Although I'm still building mine and plan to use charge-and-ride instead of your parallel connection to the EUC.)

This 20-series (84V) pack is not ideal for charge-and-ride for 84V EUC's though, because you'll need DC-DC Boost and Buck converters to enable you to safely connect the backpack at any time. And there are almost no COTS DC-DC converters >500W that accept >80V input. Better to use a 14s or smaller backpack, which won't need the Buck converter and stays inside the normal 60V range for cheap DC-DC's. I only have this GL900 because I found a used one cheap.

KS-Power is a 10s pack (42V) BTW.
 

On 8/19/2020 at 12:59 AM, Azzias said:

I had to bypass the bms on the Negative power out. I did use the gl900 bms for charging.

So the GL900 backpack has a microprocessor-controlled BMS with high-current output interruption, charging input interruption, software-controlled balancing resistors with LEDs, and 40A fusing.

It has a 4-pin interface:

  1. High-current negative
  2. Signaling wire
  3. Charging positive
  4. High-current positive

With mine, I could not get the Charging positive pin 3 to accept charging current, since I don't have the original charger to send it the necessary signaling on pin 2.

Did you find a way?
(Or do you charge through pin 4?)

The bad news is the balancing system is not active unless the BMS is put in charging mode (which I can't do yet).
Did your balancing LEDs ever turn on while charging? (They are the 20 green LEDs scattered around the top and bottom PCB; when they activate they're very bright and you can't miss them with the cover removed.)

Thx

p.s.- If you use a switch to put +VBatt on the signaling wire, it will keep the BMS awake in discharge mode, so that you won't have to bypass the negative output interruption. This way your pack can do under-voltage shutoff to protect itself from single-cell overdischarge... but it's also fussy because it considers 4.20V/cell "overvoltage" and will disable the output if you charge it that high.

Edited by RagingGrandpa

Share this post


Link to post
Share on other sites

I did not have the pin out completely figured out on the pack. I never figured out charge positive so I use the high current positive to charge. The high current positive goes directly to the cells so I left that alone. The negative when hooked to the bms On discharge which will throw an error (e6) and shut the pack off if I run parallel to my euc or even just Connected to the euc battery (battery disconnected From euc control board). I ran a 120v light bulb With the negative hooked to the bms just fine so it’s something in the euc the gl900 doesn’t like. I do have a switch on the signal wire so I can manually switch on the pack and display I did have to use a pretty high resistor to keep the signal wire from heating up though. The issue is since I moved the negative wire  the bms thinks it’s not hooked to anything (no current going through the processor) so after awhile I get a error with lots of warning beeps. I usually just leave the switch off. 

 
I was considering changing the batteries In the gl900  to Tesla 2170  5000mah Batteries and using a Bluetooth bms controller (I’m also planning on doing this on the euc pack). I have not checked the bms leds while  charging though I vaguely remember a bunch of Green leds so maybe... anyway I will check that On the  next charge. If I can’t get the bms to work while charging I’ll swap out the cells and bms. 
 
I’ve noticed the pack will throw an error if I charge past 82v (e3) I have a better charger than the gotway one that I can adjust max charging state so I may start using that. 82v is high enough charge for me. When I first started using the gotway charger is only charged to 82v now it’s at 84.3 
 
I also noticed that my gl900 percentage display only goes down in stages 100 the 88 then 56. Are you seeing this in your pack?  I also noticed that the pack will read 56 percent and the euc will read 49% so the pack must run to a lower voltage than the euc. 
 
If you have any thoughts on the chattering and possible solutions I love to hear your thoughts. You have a much better understanding of this pack than I do. Where did you get all your info? 

Share this post


Link to post
Share on other sites
On 8/19/2020 at 12:59 AM, Azzias said:
 


As a side note my mten3 is not my only experience with euc. I do have a modded ninebot c+ thats modded to 20mph

  Hide contents

 

How did you mod the C+ for 20MPH? I have a C+ and found no info on doing it to the C+. I ended up getting a V10F when they came out in 2018 because I hated the slow speed. But I'm 260 pounds so I don't think I would have much safety margin on it.

 

Share this post


Link to post
Share on other sites

I looked it up it’s 19mph not 20mph I guess I rounded. here is the link for the software mod 

http://www.mrn76.ru/index.php/en/#tm-mobile

 My original plan was to mod the firmware get the extended battery covers, get extra batteries to bring it to 500wh. 

Share this post


Link to post
Share on other sites
On 8/15/2020 at 9:50 AM, Philip W said:

Also a friendly reminder that, please don't ride-while-charge. My old EUC board now is bad probably due to that.

Thanks for the warning! It seems the usefulness of an external battery pack is limited to a few very niche situations like riding far into the wilderness, no wall plugs available, need an emegency charge source to make it back just in case. 

Nevertheless an interesting experiment. Was wondering, has anyone here found a solar charge controller that worked well with 84v batteries? Only seen 60v max ones so far.

Share this post


Link to post
Share on other sites

@Tinkererboi @Azzias@Hal Farrenkopf @RagingGrandpa @litewave @Globewheel

On 8/14/2020 at 9:50 PM, Philip W said:

Also a friendly reminder that, please don't ride-while-charge. My old EUC board now is bad probably due to that.

Hi, everyone, sorry I have to do a little announcement because a recent discovery.

I opened my KS-14C and found out my Kingsong was connected in a serial way: external charging port connects to battery one's charging port, battery one's discharging port connects to battery two's charging port, then battery two's discharging port to the mainboard of EUC.

I tested both batteries and found out they each had a BMS board. In another word, Kingsong design my wheel in a ride-while-charging way. Since they are the experts in EUC and batteries, I have no reason to doubt their design. Therefore, my statement above is no longer true. Ride-while-charging is OK, at least this is what Kingsong thinks.

My EUC board was bad should be due to other problems, not the ride-while-charging. I just want to clear it up for everyone here.

Share this post


Link to post
Share on other sites
9 hours ago, Philip W said:

KS-14C:
external charging port connects to battery one's charging port,
battery one's discharging port connects to battery two's charging port,
then battery two's discharging port to the mainboard of EUC.

Wow, really?

Perhaps this is KS's old way of coordinating charge-stop across multiple packs... but it also means "battery two" could disable "battery one" at any time (including while riding).

14C is a lower-power, older model. I expect newer KS 2000w+ rated wheels do not use this architecture.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...