Sherman-S 3600wh: 100V, 20", suspension, 97lb

[Clem604]

4 minutes ago, KiwiMark said:

Yes.  I think most of the 100.8V wheels use the same plug.

Awesome thanks

[wstuart]

40 minutes ago, Demian B said:

I know what you're talking about.  I was wondering the same.  My Mten3 sometimes makes a similar sound but the SS sounds like Mtens daddy.  My OG Sherman makes a more consistent sound where the SS sounds more variable and fluid.  Definitely similar to sound of water through pipes though.

Whew!  Thankyou.  In the first 30 miles I was a little nervous about it.  I feel more confident hearing from you that you hear the same thing. 

[Kekafuch]

39 minutes ago, Clem604 said:

Awesome, thank you! I will add this to my list of chargers I'm considering. Is there anything else needed with the charger? I'm assuming I will need a GX-16 5 pin adapter?

 

Edit: I should've read your post more thoroughly.

 

Does the Sherman S use the GX-16 5 pin?

 

The vender linked throws in a XT60 male connected to about a foot of 12awg wire. 
 

I would ask to have a XT60 female solder to the end of the foot cable. Then make short 4” dongles to connect to that for with the appropriate GX connector to the wheel you are charging.

The Sherman OG is using GX16-5. Your SS should be the same. 
 

have 2x GX16-5 connected parallel to one XT male connector for the dongle. pins 1 and 2 are positive and pins 4/5 negative. 

[wstuart]

37 minutes ago, InfiniteWheelie said:

@wstuart From my limited understanding, all suspension is "hydraulic".

I believe the hydraulic part in both cases is the rebound damping. Meaning you adjust the size of the hole the oil passes through when the suspension rises back up after a bump. This regulates (slows) how quickly how quickly it returns to it's uncompressed state.

The difference between the Sherman-S and the V13, is that the former uses a steel coil to absorb bumps, and the latter uses an air piston instead. So one uses coil suspension, the other uses air suspension. Both are "hydraulic", so no point using that word.

Correct me if I'm wrong.

Thankyou!  That makes sense..... so there is a spring in there 

[MrMonoWheel]

Yeah as far as the shock goes its kind of a Chinese to English translation thing calling them hydraulic, similar to when they called the handles lead. The shocks are standard coil shocks with shock oil acting as the damping fluid.

[wstuart]

40 minutes ago, KiwiMark said:

Coil over oil?

Oil damped spring shock?

It uses a spring instead of air, that doesn't exactly make it hydraulic.

I vote we call it "awesome".  Then we can refer to all the other suspensions as "not awesome"   

[DragonFZ]

6 hours ago, wstuart said:

Have you ridden both?  Is one more stable than the other?

I rode my OG Sherman on stock knobby tires for 2 years. I trust that tire. I am bias. To me, it gets more stable at higher speeds.

[wstuart]

Just now, DragonFZ said:

I rode my OG Sherman on stock knobby tires for 2 years. I trust that tire. I am bias. To me, it gets more stable at higher speeds.

I just got off my wheel - quick 2 mile ride for my nightly fix.

I'm really really starting to like this wheel and tire.  I can't get over how nimble it is.  This wheel impresses me more and more every time I ride it.  I guess I'm happily surprised because in the first 50 miles I was questioning my purchase because of how sketchy it felt.  It's weird how our bodies adapt and adjust...... 

[DragonFZ]

56 minutes ago, Clem604 said:

Does the Sherman S use the GX-16 5 pin?

Yes... I got that information from eWheels website.

[DragonFZ]

3 minutes ago, wstuart said:

I just got off my wheel - quick 2 mile ride for my nightly fix.

I'm really really starting to like this wheel and tire.  I can't get over how nimble it is.  This wheel impresses me more and more every time I ride it.  I guess I'm happily surprised because in the first 50 miles I was questioning my purchase because of how sketchy it felt.  It's weird how our bodies adapt and adjust...... 

After tonight's group ride, I've 146 miles total.

[techyiam]

16 minutes ago, wstuart said:

It's weird how our bodies adapt and adjust...... 

This the part I am pleasantly surprised about too. 

I cannot explain it.

When I first got on my Abrams, I was just taking it easy.

But as I rode more, my body adapts and make maneuvers that I didn't think it could do.

I do use a different technique than what I do on my V12, but it isn't more difficult, just subtlety different. 

I am also amazed at how agile a heavy wheel like the Abrams can be.

[Slartibartfast]

Are there any high current chargers that give you an option to charge to a percentage?

My current charger is set to 84v but still has two dials, one for amperage (with options from 1 to 5) and one for charge percentage (80%, 90%, 100%).

I'd be keen to get a high capacity charger but at full beans I'd only want to charge to 80%. Are there any chargers that will stop at 80%, or even better drop to a trickle at that mark or do they all thump at the set capacity till the battery is full?

[MrMonoWheel]

4 minutes ago, Slartibartfast said:

Are there any high current chargers that give you an option to charge to a percentage?

My current charger is set to 84v but still has two dials, one for amperage (with options from 1 to 5) and one for charge percentage (80%, 90%, 100%).

I'd be keen to get a high capacity charger but at full beans I'd only want to charge to 80%. Are there any chargers that will stop at 80%, or even better drop to a trickle at that mark or do they all thump at the set capacity till the battery is full?

Just set the charger to whatever voltage is 80% full? So like for the "Roger Charger" if the wheel is 100.8v, charge it to 95v? Not sure if it works this way but it might, Id assume thats what the percentage marks are on your charger.

[Slartibartfast]

9 minutes ago, MrMonoWheel said:

Just set the charger to whatever voltage is 80% full? So like for the "Roger Charger" if the wheel is 100.8v, charge it to 95v? Not sure if it works this way but it might, Id assume thats what the percentage marks are on your charger.

That's not a bad though.

I assume the Sherman-S is fully charged at 100.8v. Does anyone know what the "fully discharged" voltage is? I assume it's nowhere near 0v

Edited January 18, 2023 by Slartibartfast

[KiwiMark]

13 minutes ago, Slartibartfast said:

Are there any high current chargers that give you an option to charge to a percentage?

My current charger is set to 84v but still has two dials, one for amperage (with options from 1 to 5) and one for charge percentage (80%, 90%, 100%).

I'd be keen to get a high capacity charger but at full beans I'd only want to charge to 80%. Are there any chargers that will stop at 80%, or even better drop to a trickle at that mark or do they all thump at the set capacity till the battery is full?

I have a charger like that for my e-scooter, but I'm pretty sure that 100% just charges like any other charger and that the 90% and 80% charge settings just charge to a lower voltage, it would be pretty easy to check what voltage the battery gets to on each setting to know what that voltage is.  On the Sherman S you could pick a voltage and charge to that, then check to see what percentage the wheel says the battery is at.  Whatever voltage gets the wheel to say it is 80% charge is what you could set the charger to for 80%, ditto for 90%.  Just remember that these wheels are top balancing after the highest cells (or is it just each battery pack?) start hitting 100%, so charging to a lower percentage means no balancing will happen, so you should charge to 100% at least now & then.

[KiwiMark]

7 minutes ago, Slartibartfast said:

I assume the Sherman-S is fully charger at 100.8v. Does anyone know what the fully discharged voltage is? I assume it's nowhere near 0v

According to the details on AliExpress:

Alarm at 78V, Tilt back at 75.6V.  So I'd assume that below 75V there isn't much energy left in the battery.

[Slartibartfast]

Yeah, I do "fully charge" every so often to enable the cells to balance but I like to do so at a trickle.

Depending on how much time I have I typically charge my current wheel at 4 or 5 amps up to 80%, then "top it off" at 1 or 2 amps.
(note my current wheel came with a 1.5 amp charger so 5 amps is a fair bit over what the factory supplied)

From what I understand most the heat (and there for damage) that charging causes happens in that last part of the charge. For this reason "smart chargers" that come with mobile phones throttle the last part of the charging to preserve the longevity of the battery. This is why they make claims like "80% charge in 20 minutes" or what ever they say. That's because they can subject the charger to full load up to 80%, but then have to throttle it back to prevent batt damage.

The idea of charging at 15 amps right the way up to 100% does kind of leave me feeling a little uneasy, even if the manufacturer says it's okay.

11 minutes ago, KiwiMark said:

According to the details on AliExpress:

Alarm at 78V, Tilt back at 75.6V.  So I'd assume that below 75V there isn't much energy left in the battery.

So if we assume 100.8v is 100% and 75v is 0%, does that mean 80% is as simple as: 75 + (100.8 - 75) * 0.8 = 95v

[KiwiMark]

35 minutes ago, Slartibartfast said:

So if we assume 100.8v is 100% and 75v is 0%, does that mean 80% is as simple as: 75 + (100.8 - 75) * 0.8 = 95v

No, definitely not - although 95V is probably not far off and you could certainly try that and see what charge level the wheel shows at 95V.  The voltage on Li-Ion cells doesn't drop in a straight line linear fashion, so it won't work exactly where every 0.01V = x%.

100.8V is 4.2V per cell for a 24 cell (in series) battery.  It is pretty normal for Li-Ion cells to be considered 100% charged at 4.2V.

According to battery university - https://batteryuniversity.com/article/bu-409-charging-lithium-ion the 90% charge is at 4.1V and the 80% is at 4.0V.  So there for an 80% charge is 4.0V x 24 = 96V (yep, 95V was in fact pretty close) and a 90% charge is 4.1V x 24 = 98.4V

(Stupid thing posted before I finished writing it)

Edited January 18, 2023 by KiwiMark

[Slartibartfast]

So how would one calculate 80% charge?

[mrelwood]

5 hours ago, wstuart said:

We say it's hydraulic because we don't have to buy a 600 psi pump and constantly check and top the thing off as we would with most other euc suspensions, and there is no visible spring.

Two things: Air vs coil, and visible spring vs hidden spring. Neither has anything to do with hydraulic.

5 hours ago, wstuart said:

This suspension is different from any other euc suspension. 

That is correct. So are V11, V13, EX, S22, and Commander Pro though.

5 hours ago, wstuart said:

If calling it "hydraulic" is "annoying", than what is the proper word to describe the difference. 

I don’t mind stuff that are annoying, but calling it “hydraulic” is misleading. The V11 suspension is not hydraulic, all other EUC suspensions are. The correct term (besides @wstuart’s genius “awesome” ) would be “The ShermS Suspension”. TSSS in short…

 

3 hours ago, Slartibartfast said:

From what I understand most the heat (and there for damage) that charging causes happens in that last part of the charge. For this reason "smart chargers" that come with mobile phones throttle the last part of the charging to preserve the longevity of the battery. This is why they make claims like "80% charge in 20 minutes" or what ever they say. That's because they can subject the charger to full load up to 80%, but then have to throttle it back to prevent batt damage.

I don’t believe that to be an accurate explanation.

 All battery chargers throttle the charge current at the end of the charge. It’s because the charging voltage reaches the maximum allowed voltage, so the internal battery voltage and the charging voltage start getting closer to one other. The charging current is determined by the difference between those voltages, so it will drop.

 Once the charging current reaches the maximum, the constant current part of the charging process turns into the constant voltage part, which takes roughly a third of the whole charging process. During this time the charging current gets lower and lower, eventually low enough to trip the charger’s green LED threshold. Charging still continues very slowly though.

 You can usually monitor the charging current from either the charger or an EUC app. It will show what I described.

3 hours ago, Slartibartfast said:

The idea of charging at 15 amps right the way up to 100% does kind of leave me feeling a little uneasy, even if the manufacturer says it's okay.

Don’t worry, it doesn’t. Remember, the charging voltage and the internal battery voltage are different, so even if the wheel says 100% during charging, that’s not where the battery’s at. Unplug the charger mid charge and the battery voltage will drop a bit as it levels out. 

2 hours ago, Slartibartfast said:

So how would one calculate 80% charge?

Many wheels have their own custom proprietary voltage to percent curve, which is sometimes even improved on by firmware updates.

 Percentage doesn’t equal voltage, so if you need to describe the battery voltage, use volts, not percents. For calculating the voltage for so called 80% charging (which I believe to be a bad idea through and through), your formula was easily precise enough.

 

 For more info on 80% charging, you might want to watch my video on it regarding EUCs:

 

[wstuart]

7 hours ago, mrelwood said:

 

 For more info on 80% charging, you might want to watch my video on it regarding EUCs:

 

Thankyou!  That video is very informative

Edited January 18, 2023 by wstuart

[DragonFZ]

8 hours ago, Slartibartfast said:

Are there any high current chargers that give you an option to charge to a percentage?

My current charger is set to 84v but still has two dials, one for amperage (with options from 1 to 5) and one for charge percentage (80%, 90%, 100%).

I'd be keen to get a high capacity charger but at full beans I'd only want to charge to 80%. Are there any chargers that will stop at 80%, or even better drop to a trickle at that mark or do they all thump at the set capacity till the battery is full?

Not a good idea. Can't remember where I read it at. Someone did the 80% charge and once a month full charge to balance the battery. The wheel he did fully charge when needed, lasted longer than the 80% charge wheel. Only that one guy opinion.

Fact: Sherman S (like the OG Sherman) has dumb BMS, which only balance the battery when fully charged.

Question: My Sherman S charger only charges up to 100.4 V consistently.  My OG Sherman charger, I can charge up to 100.9 or 101.0     What voltage are you guys charging up to?

[Slartibartfast]

12 hours ago, mrelwood said:

For more info on 80% charging, you might want to watch my video on it regarding EUCs:

Wow, that was an amazingly relevant video!
I even checked the publication date part way through just to make sure it wasn't actually made in response to this discussion: 

Thanks Elwood.

Edited January 18, 2023 by Slartibartfast

[Funky]

Video by: EcoDrift-Life Разбираем Veteran Sherman-S (teardown)

 

[wstuart]

13 hours ago, DragonFZ said:

Not a good idea. Can't remember where I read it at. Someone did the 80% charge and once a month full charge to balance the battery. The wheel he did fully charge when needed, lasted longer than the 80% charge wheel. Only that one guy opinion.

Fact: Sherman S (like the OG Sherman) has dumb BMS, which only balance the battery when fully charged.

Question: My Sherman S charger only charges up to 100.4 V consistently.  My OG Sherman charger, I can charge up to 100.9 or 101.0     What voltage are you guys charging up to?

EUC world says that my Sherman is charging to 101v.  Is would guess that 100.4 is within the acceptable range.

Where are you seeing 100.4v?  On the charger?  Euc world?