Poll: Have you experienced an unexpected shut-off while riding?

[tjcooper]

Team,

thanks for all the comments.

The IPS 14" unit is an "I130" unit with 130Wh battery.   I see on eBay new ninebot one E+ at $769 with free shipping.   So I am not clear what offer to make to Banggood.  I paid $279 and have put in $40 of shipping and parts.  so maybe $520 is a good compromise.   My problem is that I still don't know if I really like the sport but I think one the "unexpected stops" come to a halt I will really enjoy it.

QUESTION:  I am a real battery "meistro" for my electric bike and rc planes and drones.  Does anyone make their own batteries for EUC from the good quality 18650 units?

     tjcooper

[SlowMo]

34 minutes ago, tjcooper said:

Team,

thanks for all the comments.

The IPS 14" unit is an "I130" unit with 130Wh battery.   I see on eBay new ninebot one E+ at $769 with free shipping.   So I am not clear what offer to make to Banggood.  I paid $279 and have put in $40 of shipping and parts.  so maybe $520 is a good compromise.   My problem is that I still don't know if I really like the sport but I think one the "unexpected stops" come to a halt I will really enjoy it.

QUESTION:  I am a real battery "meistro" for my electric bike and rc planes and drones.  Does anyone make their own batteries for EUC from the good quality 18650 units?

     tjcooper

You can check with @Jug, @Tomek, @esaj and others. They make their own battery packs from better brands.

[Chriull]

1 hour ago, tjcooper said:

Team,

thanks for all the comments.

The IPS 14" unit is an "I130" unit with 130Wh battery.   I see on eBay new ninebot one E+ at $769 with free shipping.   So I am not clear what offer to make to Banggood.  I paid $279 and have put in $40 of shipping and parts.  so maybe $520 is a good compromise.   My problem is that I still don't know if I really like the sport but I think one the "unexpected stops" come to a halt I will really enjoy it.

QUESTION:  I am a real battery "meistro" for my electric bike and rc planes and drones.  Does anyone make their own batteries for EUC from the good quality 18650 units?

     tjcooper

Personally i would never go for an EUC with just 130Wh. This means that one only has cells in series and none in parallel. So the maximum (continous) current from this pack with actual state of the art liions would be 10-15A. This would deliver just the rated power of the motor of the IPS i130...

With the 340Wh pack of the E+ you have twice the continous current and so twice the power ("safety reserve"). But this still leads to incidents from time to time - unfortianately just another actual one (http://forum.electricunicycle.org/topic/3866-dysfunctional-ninebot-crash-thoughts/).

Another "specialty" of the Ninebot is, that they use battery packs with 15 cells in series instead of the "normal" 16 cells. So this could maybe put you in the situation to use the high power/high current/fastchargeable RC Lipos with 3 cells (5 pieces of them...) I think @EUC Extremeused/uses such cells and there was also sometimes a discussion with this cells and ninebot, imho? But i don't remember any details or outcome...

Ninebot E+ battery packs use high quality 18650 cells - just the BMS has one "shortcoming" (regarding the balancer): http://forum.electricunicycle.org/topic/2247-decrease-charging-time-5a-high-current-charger-mod/?do=findComment&comment=39638

The cells are "The battery cells are LGDBMG11865 which translates to LG 18650 2900mAH batteries (2850mAH nominal)." (Info from the same thread link...)

 

[esaj]

4 hours ago, SlowMo said:

You can check with @Jug, @Tomek, @esaj and others. They make their own battery packs from better brands.

I didn't build my battery packs myself, I ordered them custom-made... IF I had a battery spot-welding machine (the kind with the prongs on the same side, you don't want to weld "through" the cell ), I could maybe try, but I don't trust simple solder joints between the cells to hold, not to mention the risk of overheating a cell during soldering. For balancing, solder-joints (and flexible cables) are probably OK, but IMHO the cell tabs should be welded directly to the cells and together, so they don't come off during vibrations or crashes. The kind of BMSs with solder-spots for the tabs & cells with pre-welded tabs could work also.

I don't remember if it was @Jug or @Tomek or someone else, but someone here did make their own battery packs from single cells, using a homemade spot-welder.

[Jug]

12 hours ago, tjcooper said:

QUESTION:  I am a real battery "meistro" for my electric bike and rc planes and drones.  Does anyone make their own batteries for EUC from the good quality 18650 units?

I did make my battery pack, you may see it here but that is from "good" batteries from used laptop batteries! This pack helped me to "boost" my 130w original battery pack so i got better autonomy to 25km, with original 130w i had 6-7km autonomy.

Now i am in process to build high quality 18650 pack with this batteries Samsung INR18650-30Q 3000mAh - 15A

 

And i am almost finished building this spot welder for battery tabs just waiting for 3s BMS and need to find some old 12v car battery  

 

[Jug]

Why i can not add more pictures? 

@esaj?

[esaj]

Just now, Jug said:

Why i can not add more pictures? 

There's limited amount of space per user for adding attachments like pictures. I suggest you use an external site, like http://imgur.com/ , you can even upload pictures there without registering (but then finding them later on might be hard, like I noticed last year ). Just grab the URL under "Direct Link (email & IM)" after you've uploaded, paste it into your post and hit enter. The forum software should attach your image directly to your post.

[Jug]

1 minute ago, esaj said:

There's limited amount of space per user for adding attachments like pictures. I suggest you use an external site, like http://imgur.com/ , you can even upload pictures there without registering (but then finding them later on might be hard, like I noticed last year ). Just grab the URL under "Direct Link (email & IM)" after you've uploaded, paste it into your post and hit enter. The forum software should attach your image directly to your post.

Ok, will do it! 

Thanks @esaj

[EUC Extreme]

I am using 16 cells in series and two in parallel.
I'll upload the cells in two parts. Two of the charger.

[esaj]

33 minutes ago, Jug said:

And i am almost finished building this spot welder for battery tabs just waiting for 3s BMS and need to find some old 12v car battery  

Never thought it would be that easy to make, I just remember someone mentioning you need a transformer from an old microwave-oven, so didn't ever check it further  But I guess it works just fine as long as the amperage is high enough. Actually, the device is so simple I could design one myself (but don't have any power source that could provide enough amperage, and I'm not confident enough to design anything that plugs into mains ).

[Jug]

4 minutes ago, esaj said:

Never thought it would be that easy to make, I just remember someone mentioning you need a transformer from an old microwave-oven, so didn't ever check it further  But I guess it works just fine as long as the amperage is high enough. Actually, the device is so simple I could design one myself (but don't have any power source that could provide enough amperage, and I'm not confident enough to design anything that plugs into mains ).

Yes, it is me, i builded one from microwave-oven but i am also afraid to try it on batteries, i can not test the amperage so that was no-no for me. 

That's why searched more and i found this arduino based, i just waiting for 3s bms to arrive, apparently the "author"  of arduino spot welder did answered on one question regarding battery power "amperage", he mentioned we can use this Lipo so i wonder can we use the li-ion in 3s that give +-12v, is there enough amperage in there?

Can that be done with Li-ion? 

[esaj]

8 minutes ago, Jug said:

Yes, it is me, i builded one from microwave-oven but i am also afraid to try it on batteries, i can not test the amperage so that was no-no for me. 

That's why searched more and i found this arduino based, i just waiting for 3s bms to arrive, apparently the "author"  of arduino spot welder did answered on one question regarding battery power "amperage", he mentioned we can use this Lipo so i wonder can we use the li-ion in 3s that give +-12v, is there enough amperage in there?

Can that be done with Li-ion? 

The amperage used on the spot-welders can be from 400A up to several thousand amperes... that's a hell of a lot of current. A single 18650 Li-Ion cell can give out something like 10A-40A max in the "safe operating" range depending on the cell type, so to be on the safe side, you probably need to put lots (10-40?) more cells in parallel so they don't die or explode on you   "Lipos" (basically Li-Ions in pouch packaging) have much lower internal resistance, and even a single cell can give out something like 100A (high quality ones, I believe).  A high-discharge car battery can give out hundreds of amperes in peak spikes, so probably a much better choice.

[Jug]

Thanks @esaj, 

So i will need to find some old car battery! 

[esaj]

14 minutes ago, Jug said:

Thanks @esaj, 

So i will need to find some old car battery! 

In my (uneducated in this) mind, yes, that would seem the safest choice:

A 40Ah automotive battery will generally happily crank at around 400 A and may be able to be persuaded to supply 600A under protest.

What I think "crank" here means is starting the car (running the starter motor)... the amperage in short spikes (very short spikes a few milliseconds apart or whatever is used in the spot-welders) could be even higher.

Now that I think about it, a spot-welder is actually really simple to make: basically you have a bunch of power mosfets (enough so the legs don't explode with the current spike ) with a large heatsink, a very low resistance (thick cables) path for the actual welding current, and a microcontroller to time the welding. Looking at the Arduino-design, one could probably even take away the mosfet-driver chips and simply replace them with a totem-pole/push-pull -drive for the mosfet gates?

EDIT: Reading a bit more, there are separate "Start"/"Starter" -car batteries specifically meant out to crank very high currents for starting a car/other vehicle. Again, I'm no expert in these, but it sounds like that's the kind that would best suit a battery-driven welder.

[Jug]

4 minutes ago, esaj said:

Looking at the Arduino-design, one could probably even take away the mosfet-driver chips and simply replace them with a totem-pole/push-pull -drive for the mosfet gates?

Uh, i am totally uneducated in this  

I can just follow someone's instructions and maybe change something irrelevant, but that is all! 

[esaj]

21 minutes ago, Jug said:

Uh, i am totally uneducated in this  

I can just follow someone's instructions and maybe change something irrelevant, but that is all! 

Hehe, mostly just "thinking out loud"...  Those chips are probably the most expensive parts in the design (leaving out the battery), so I was just thinking if it would be possible to do away with them   "High" current (for those chips, 3A) is needed to "open" and "close" the mosfets (ie. start & stop the welding) fast, so Arduino cannot be wired directly into the gates (it can only supply/sink about 20 or 40mA, 0.02-0.04A), and something is needed in-between to "drive" the mosfets. Relays are way too slow, and can vibrate during open & close, so a solid-state component is needed. Basic push/pull -driver is simply two transistors (and maybe a resistors or two if current limiting is needed to protect the transistors), so something like this MIGHT work:

It's a very quick design of the top of my head, and would need to be tested (without a car battery! ) at first, to see that the mosfets open & close fast enough etc. And of course there'd be much more than one mosfet... the transistors might have to be darlington-pairs to give out enough current gain...

But since you already have the device, this really doesn't concern you

[Jug]

4 minutes ago, esaj said:

But since you already have the device, this really doesn't concern you

But good finding and exploring the possibilities for future builders, now you have something new to play with and banging head 

GOOD LUCK!!! 

[OleTC]

13 hours ago, tjcooper said:

Team,

thanks for all the comments.

The IPS 14" unit is an "I130" unit with 130Wh battery.   I see on eBay new ninebot one E+ at $769 with free shipping.   So I am not clear what offer to make to Banggood.  I paid $279 and have put in $40 of shipping and parts.  so maybe $520 is a good compromise.   My problem is that I still don't know if I really like the sport but I think one the "unexpected stops" come to a halt I will really enjoy it.

QUESTION:  I am a real battery "meistro" for my electric bike and rc planes and drones.  Does anyone make their own batteries for EUC from the good quality 18650 units?

     tjcooper

Hello,

Being a Young man at age 60, I have built my own spotwelder, using the trafo of a discarded microwave-oven. It is controlled by an Electronic Circuit based on 2 555 IC timers and a solid state relay.

It took me long time to construct and adjust the welder. The final welding, soldering and assemblage of the BMS took me few hours.

What I'm saying is, You can buy quality cells with nickel strips welded on both ends, ready for assemblage to a BMS-board that is constructed for this, You just need to solder, insulate the cells from shorting and finally wrap the pack. As an Expert in batterypacks , You should have en excellent Foundation for this. There's no reason to do the spotwelding unless You're up to a challenge. I opened a thread on this build. Guess it is called 'Yet another homemade batterypack.' You can look it up.

I highly recommend a good quality batterypack. I discern sharply between before and after I installed the new pack in my cheap generic X3-clone. And I 'm having a ball riding it around. Just went to the mart on it to buy milk and a couple other Things.

[esaj]

2 hours ago, OleTC said:

Hello,

Being a Young man at age 60, I have built my own spotwelder, using the trafo of a discarded microwave-oven. It is controlled by an Electronic Circuit based on 2 555 IC timers and a solid state relay.

Probably a stupid question (I'm full of those ), and I know this topic has gone way off-topic, no thanks to me , but I just want to know if there's any other reason for using a microwave-oven transformer for the mains-plugged spot-welders other than pushing down the voltage so the fuses don't blow?

[OleTC]

10 hours ago, esaj said:

Probably a stupid question (I'm full of those ), and I know this topic has gone way off-topic, no thanks to me , but I just want to know if there's any other reason for using a microwave-oven transformer for the mains-plugged spot-welders other than pushing down the voltage so the fuses don't blow?

There's only good questions. The microwave-oven trafo is used due to it's size. The ability to deliver high current for the weld is very much dependant on the size of the trafo. The one I used was from a Molineux oven and rated 1440 Watt max. capacity. It is a big lump of iron.

[Reivax]

On 4/29/2016 at 7:41 PM, Jug said:

Now i am in process to build high quality 18650 pack with this batteries

Amazing ! Please let us know the outcome !

[Jug]

18 minutes ago, Reivax said:

Amazing ! Please let us know the outcome !

Of course, i will keep you updated!  

[nute]

I experienced my first face plant today, or rather an arse plant. Riding along the canal tow path in Newbury, went over a bridge both sides of which were quite steep. I went up the first side no problem but on the downside the wheel just went out from under me. I feel that I was probably leaning back to far and just went beyond the wheels ability to compensate for my over lean. The battery was at about 80% and I wasn't going but maybe 6-7 mph. 

Fortunatly I tend to ride it with a strap tied to the handle or it might have gone into the canal. 

There were quite a few people about and a did see a few folks filming me as I went past, don't think my arse plant was caught on film tho.

[Jug]

2 minutes ago, nute said:

don't think my arse plant was caught on film tho

If they caught you, maybe we will see you on youtube 

Joke a side, you did not hurt yourself too much i hope?

What EUC you have?

 

[nute]

Yeah, ill be looking for myself on those fail compilation utube channels, man does arse plant on ECU. There will be lots of bleeping on the soundtrack tho as i was swearing a bit

Didn't hurt myself, few cuts on fingers but was wearing wrist guards so they took the worst of it. I have an IPS 191 340w/h