Chargers - talk to me

[rinzler]

As above really, I am not so fussed about fast charging (30mile range on the Tesla will see me right for several days) however I do take note of the wisdom here about maintaining a battery regime to keep the wheel in tip-top shape. 

The original charger supplied would do the trick were it not for the whole 20%-80% optimal charging range. My original plan was to just get a Charge Doctor and set the upper limit on it and use it via the original supplied charger. However since the Charge Doctor is out of town evidently, I am stuck for options.

5amp fast chargers at £120 is a bit overkill for me. I won't be in a situation where I need to rapidly charge the wheel. 

I found the cycle satiator which looks super cool but again very expensive - plus I'm not even sure it does what I need it to do (and work on UK 240v).

So I put it to you ewheel chums to guide me back into the light (whilst preserving my wallet).

It seems @Jason McNeil at ewheels has the Charge Doctor in stock (although only the dual exit variant) so that is an option to buy if this is the best route.

To re-iterate my aim here is to safely charge the battery of my Tesla to 80% as recommended by you lot, UNATTENDED (no fires please...)  which will auto shut-off once it reaches that value. The cheaper the better!

I'll try not to be swayed by cool graphical displays...

[esaj]

Outside of Charge Doctor, I don't know of any really cheap alternatives, although such might exist. The voltages the wheels use are "unusual", as most electronics run on something like 3.3V-12V (typical values 3.3/5/9/12). You could put in an order for a CD and just wait for it, or buy one of the more expensive options... or just use a timer on the charger to shut it off after some hours, but it's not a very accurate method. Still, if you keep using the wheel all the time, charging it to full shouldn't be that big of a problem, if you don't leave it laying around fully charged for longer whiles (like weeks or months), or store it in a very hot place.

[Hansolo]

The Satiator work on 240V, I use it in France.

[rinzler]

1 hour ago, Hansolo said:

The Satiator work on 240V, I use it in France.

 It's a sexy piece of kit.  But it's sooooo expensive!  In real terms I'd be charging once a week. The satiator, though i want it, feels overkill. 

Can i plug the charge doctor in to the normal supplied charger or do i need to change that too?

I could probably ship the charge doctor from eWheels to the uk and it still be cheaper than the satiator!

[Seba]

12 hours ago, rinzler said:

To re-iterate my aim here is to safely charge the battery of my Tesla to 80% as recommended by you lot, UNATTENDED (no fires please...)  which will auto shut-off once it reaches that value. The cheaper the better!

I would say that by charging in this way you increase the risk of self-ignition of the battery in the longer run. Battery cells DO imbalance with time and mileage, it's just unavoidable. There are always small variances between each cell, even in new. This variation increases over time and usage. By charging to 80% you effectively disables BMS balancing feature, so it's possible that after some longer time cell voltages will start to differ significantly. It's a short way to SINGLE cell failure, then SINGLE cell self-ignition causing a WHOLE wheel to stand on fire... If you ride frequently, just charge it to full after each ride. If you don't plan to ride soon, leave your wheel as is or charge it partially to ~50% if was almost depleted. That's all.

[svenomous]

Imbalance is a real issue, but I believe a 100% charge done every 10 charge cycles or so is plenty to keep the cells balanced, and charging to 80 or 90 percent the rest of the time (unless full charge is needed) is better for the pack overall than always engaging the balance circuit by fully topping off the pack on every charge. 

[Chriull]

9 hours ago, rinzler said:

I could probably ship the charge doctor from eWheels to the uk and it still be cheaper than the satiator!

Or you get their charger. They have one with "auto-shutdown on reaching set voltage point"

[rinzler]

42 minutes ago, Chriull said:

Or you get their charger. They have one with "auto-shutdown on reaching set voltage point"

Its like $150 or something though! I think if i spent that money I'd go with the satiator just because it's supposed to be a silent runner.

I'm in the EU (maybe not for much longer) so there is another shop eu.nicycles i think it's called that has a very similar looking one as the eWheels fast charger. So another likely cheaper route due to no import tax. 

But based on what @Seba and @svenomous is saying, for my need i am perhaps overthinking this.

Like just use the normal charger. Charge to full. Unplug. Use to 2 bars (20%) charge again. No problem.

Satiator though... 

[esaj]

24 minutes ago, rinzler said:

Its like $150 or something though! I think if i spent that money I'd go with the satiator just because it's supposed to be a silent runner.

I'm in the EU (maybe not for much longer) so there is another shop eu.nicycles i think it's called that has a very similar looking one as the eWheels fast charger. So another likely cheaper route due to no import tax. 

But based on what @Seba and @svenomous is saying, for my need i am perhaps overthinking this.

Like just use the normal charger. Charge to full. Unplug. Use to 2 bars (20%) charge again. No problem.

Satiator though... 

https://www.1radwerkstatt.de/epages/80603321.sf/en_GB/?ObjectPath=/Shops/80603321/Products/Charger

 

Chargers from 100 W to 1500 W in all voltages

 

Output voltage according to customer requirements (one week delivery time)
Current chargers in stock
Chargers of the highest quality
Aluminum casing
Line filter on the input side
Circuit protection, overvoltage protection, overcurrent protection, temperature monitoring in the charger
If desired, the charge termination to 80% or 90% thus a substantial increase in the lifetime of the battery

According to data sheets, a previous charge (80%) results in a battery life of up to 3 times.

 

The battery should be fully charged every 20 to 30 charges with the original charger, as only the balancers work and minimum balance differences are compensated.

 

This is not necessary for batteries (for example original Ninebot) without a balancer circuit. (These batteries have limited durability by saving this necessary balancer circuit)

 

 

Edited May 11, 2019 by esaj

[nickysneids]

On 5/11/2019 at 6:18 AM, esaj said:

The battery should be fully charged every 20 to 30 charges with the original charger, as only the balancers work and minimum balance differences are compensated.

This is interesting and this thread is the first I've heard of that. I bought the rapid charger from ewheels and there is some information on how to charge to 80% and why it is better but I read nothing about the need to "re-balance" the battery every 20-30 charges with the OG charger. Is there any more information about charging cycles I should know, or a place where I could learn more info about this?

I'm going to be using the Gotway MCM5 charger/rapid charger... is it best to use the wheel and run the battery down then recharge to 100% with the original charger for the first charge like with an iPhone/Smart phone battery? And when charging to 100% with the original charger, will the charger automatically stop the transfer of power once it has reached 100%?

[esaj]

22 hours ago, nickysneids said:

This is interesting and this thread is the first I've heard of that. I bought the rapid charger from ewheels and there is some information on how to charge to 80% and why it is better but I read nothing about the need to "re-balance" the battery every 20-30 charges with the OG charger. Is there any more information about charging cycles I should know, or a place where I could learn more info about this?

In a nutshell, most wheel BMSs have a basic balancing circuitry, but they only work when the wheel is charged to full (there are better so-called "active" balancers, but I don't think any wheel has them?). It's not necessary to do every time, but over time, the cells will discharge to slightly different levels and then not all of them charge fully (or if it's a really crappy BMS, it could allow some cells to overcharge). The more deeper discharged cells will start to fail sooner than the others, and might even die.

For more information, you could start with  https://batteryuniversity.com/learn/article/bu_803a_cell_mismatch_balancing   and Battery University in general, they have lots of good articles about batteries:  https://batteryuniversity.com/learn/

 

Quote

I'm going to be using the Gotway MCM5 charger/rapid charger... is it best to use the wheel and run the battery down then recharge to 100% with the original charger for the first charge like with an iPhone/Smart phone battery?

Li-ions don't need "conditioning" or be run all the way down before recharging, like some other chemistries which have the "memory effect" (such as NiMH). Li-ions can be "randomly" (meaning starting charging at some battery level and stopping before full) charged without problems, except for the balancing issue mentioned above when the battery consists of multiple serial cells, but it should be enough to do a full charge every now and then.

To ensure that the balancing occurs, you should leave the charger on the wheel for a while even after the "light goes green" to show that the battery is full. The balancing occurs at very low current compared to normal charging, when the cells are nearly at their maximum voltage.

Quote

And when charging to 100% with the original charger, will the charger automatically stop the transfer of power once it has reached 100%?

The chargers are "dumb" bricks with constant current / constant voltage -output, meaning when the battery isn't yet near full, the current is regulated to some amount (constant current -mode, usually 2A for the basic chargers), so the output voltage is lower than maximum, and once the maximum voltage has been reached (constant voltage -mode), the current will start to drop as the actual battery voltage starts to raise towards the same maximum (less voltage difference between battery and charger over more or less constant resistance -> less current). The red/green -light on the chargers usually changes color somewhere around 200mA (0.2A) or such, but for balancing, you should leave it there longer.

One last warning: I've heard of, had and re-adjusted chargers that give out slightly wrong voltage (typically too low, then the charger will never charge the wheel fully or balance the cells), so best check the output voltage of the charger to make sure it's correctly adjusted (a basic $10-20 multimeter is enough for this, they can typically handle up to 200V DC if not more). If it's giving too high voltage and for some reason the BMS doesn't have overvoltage protection on the charging side (I think all the "brand"-wheels should have the protection, but can't 100% guarantee it), then in the worst case it could cause a fire.

Edited May 15, 2019 by esaj

[nickysneids]

12 minutes ago, esaj said:

In a nutshell, most wheel BMSs have a basic balancing circuitry, but they only work when the wheel is charged to full (there are better so-called "active" balancers, but I don't think any wheel has them?). It's not necessary to do every time, but over time, the cells will discharge to slightly different levels and then not all of them charge fully (or if it's a really crappy BMS, it could allow some cells to overcharge). The more deeper discharged cells will start to fail sooner than the others, and might even die.

For more information, you could start with  https://batteryuniversity.com/learn/article/bu_803a_cell_mismatch_balancing   and Battery University in general, they have lots of good articles about batteries:  https://batteryuniversity.com/learn/

Li-ions don't need "conditioning" or be run all the way down before recharging, like some other chemistries (such as NiMH), they can be "randomly" (meaning starting charging at some battery level and stopping before full) charged without problems, except for the balancing issue mentioned above, but it should be enough to do a full charge every now and then

Dude thanks so much for the info! Really appreciate you taking the time to help me understand this.

[maltocs]

I bought a fast charger for a replacement for a broken original gotway 84V charger. I usually set it at 80 or 90% unless I know I'm going for a long ride.

But BEFORE I bought this charger, I had a mental note of HOW many % of charge I would get with the ORIGINAL charger PER HOUR and used a $10 amazon countdown timer to get it to 80-90% before it turned itself off which worked and STILL works great. 

QUESTION: is it okay to LEAVE  the charger plugged into wheel when there is NO power going to it. I haven't noticed any discharging effects or other problems, but I've always wondered about this. 

[Pete G]

Just looked at ewheels, $40 postage to uk, makes it unrealistic to me.