Battery size effect on performance

[RoCan]

Hi all 

I’ve read many threads on here discussing battery size and it’s effect on performance but much of it goes over my head. There also seems to be so many variables during these comparisons as often between different wheels and riders. Apologies if this has been discussed. Perhaps someone could post a link.

I’m looking to upgrade to an MSX. I ride off road fairly hard for up to an hour (before I’m knackered).  So large batteries for extra range is not a requirement especially with the added weight.

A whole load of new MSX stock has just appeared in the Netherlands on ebay (so tempting to avoid possible taxes from China). They are offering surprisingly small battery sizes compared to the normal 1600wh. My question relates to these battery options effect on acceleration and top speed assuming same rider is 197cm / 215lbs.

84V / 800wh

84V / 1300wh

84V / 1600wh

100V / 1230wh

I’ve also read that bigger batteries are safer, especially with big riders. Does this really come into play if I’m happy to keep it charged and do not ride long distances?

Any advice would be really appreciated and as I haven’t found any definitive figures online (unless I’m looking in wrong place?) I’d expect a lot of opinion rather than fact.

Many thanks in advance 

P.s. This forum is addictive!

[Rywokast]

how far are we talking here.. battery size will have little to no effect on performance if you keep it at above ~60% when idle.. at 215 lbs thats definitely not an hour of riding on an 800 wh wheel lol not unless youre keeping to speeds of 15 kph.. its impossible to give a definitive answer it will rely on your speed mostly, but also the terrain and temperature and your riding style in general.. the price for the increased battery size is not relative.. its much better to get the larger battery size since youre already paying like 1200 US at least for just the wheel, so you might as well spend an extra few hundred on a bigger battery version... for me personally i would say anything under 1600 is a waste since its already a top end EUC.. what is your riding style and preferred speed? i suppose if you literally never went more than 30 km at a time and dont mind charging every time you ride you could get the 800 wh version, just seems kind of pointless to me then to get an msx at all since its an expensive wheel on its own and is probably one of the worst on battery due to the tire size and agressive handling.. just give us a bit more info on your riding style, average speed, terrain and whatnot

Edited June 20, 2019 by Rywokast

[RoCan]

7 minutes ago, Rywokast said:

how far are we talking here.. battery size will have little to no effect on performance if you keep it at above ~60% when idle.. at 215 lbs thats definitely not an hour of riding on an 800 wh wheel lol not unless youre keeping to speeds of 15 kph.. its impossible to give a definitive answer it will rely on your speed mostly, but also the terrain and temperature and your riding style in general.. the price for the increased battery size is not relative.. its much better to get the larger battery size since youre already paying like 1200 US at least for just the wheel, so you might as well spend an extra few hundred on a bigger battery version... for me personally i would say anything under 1600 is a waste since its already a top end EUC.. what is your riding style and preferred speed? i suppose if you literally never went more than 30 km at a time and dont mind charging every time you ride you could get the 800 wh version, just seems kind of pointless to me then to get an msx at all since its an expensive wheel on its own and is probably one of the worst on battery due to the tire size and agressive handling.. just give us a bit more info on your riding style, average speed, terrain and whatnot

Thanks for your reply. I see your point regarding it being a high end wheel however I struggle to see how these wheels are the price they are to be honest. My car costs less than most of the big ones!  So if spending £400 less will get close to the same result for me I’d likely save the moolah. If it’s a fair increase in acceleration and top speed I’d consider it. I guess I need to see the value in it.

So my trails are hilly and rough mixed with flatter smoother ones. I prefer the technical challenges rather than bombing it for miles on end, but I do a bit of everything. I guess in summary, the opposite of cruising which is why I’m going for the MSX over the 18XL. Also upgrading from an MSV3 so its a familiar format. 

The MSV3 is only 680wh and that is ok with me range wise, it’s just lacking in oomph and I’m hoping the MSX won’t beep at me when ascending moderate hills.

Hope this sheds some light on my situation. I am still fairly new to EUC’s and this new purchase I would hope to last some time. So a bigger battery would allow for my increased stamina but I know I will definitely not be riding on roads so the long range batteries will be a waste, if there are few other benefits.

[RoCan]

Sorry, to answer your question re: speed. I’m not sure as I find the App too annoying and haven’t tried other ones out yet. I would guess average 20kph, a few top end blasts but more lower speed loose surface climbs and root manoeuvring.

Thinking about it, the acceleration is more important than the top speed, which I know you get from smaller wheels but I need the 18”+ for the terrain.

[Chriull]

1 hour ago, RoCan said:

I’ve also read that bigger batteries are safer, especially with big riders. Does this really come into play if I’m happy to keep it charged and do not ride long distances?

"Keeping it charged" is not recomendable - keeping the batteries fully charged degraded them over a year to about 80% capacity.

2 minutes ago, RoCan said:

So a bigger battery would allow for my increased stamina but I know I will definitely not be riding on roads so the long range batteries will be a waste, if there are few other benefits.

Battery life cycles are calculated as full cycles - so charging it two times for half the capacity is one charge cycle.

Max lift cut off speed depends directly on the battery voltage - with 100% charge one has 84V (4.2V*20=84V) versus 3.3V*20=66V with 0% charge. So the safety margin goes down with lower battery charge.

And one main point from the higher capacities is, that they have 6(?8?) battery cells in parallel and the smaller ones "just" 4. So they cannot deliver as much current (==torque) in peak burden situations, and in peak burden situations they have a higher voltage sag == less speed/safety margin available.

[Daniel-Son]

It seems to me if you are happy with the range of the MSV3/680WH,  you should be happy with the MSX/800WH. Then you can save some money. But if I can  squeeze a little more money, I would get 1300WH, that’s 500WH more than the 800. 

Any MSX is going to give you the oomph that you need, it just a matter of how long you want to ride. 

[Rywokast]

yes as stated the msx will absolutely give you a lot more torque and raw power than the V3S no contest there and if its 680 and fine then i guess 800 should be ok for you,, like i said 800 or 1600 there will be no power difference, its just obv the bigger battery will give you 100% performance for a lot longer.. but remember like I said the msx is not so kind on the battery, it's a power hungry machine with is raw power, torque, and fat tire don't expect the battery increase to be linear.. an msx 800 would likely be good for as long as the v3s 680.. if you can I would really recommend springing for the 1300.. from what it sounds like you like to do, that type of riding is much harder on the battery even at 20 kph than it would be going 30 kph steady on tarmac.. speeding up and slowing down a lot especially from stand still are what eat up the battery the most relatively, not cruising at an average speed.. but at least you have something to compare it against, if the 680 is more than good enough for you and you're certain, then the 800 will be absolutely fine.. maybe it's just me but whenever I get on a wheel I don't want to get off until the battery runs out haha it's like an addiction

Edited June 20, 2019 by Rywokast

[RoCan]

3 hours ago, Chriull said:

Keeping it charged" is not recomendable - keeping the batteries fully charged degraded them over a year to about 80% capacity.

Good to know thanks. I guess I meant charge more frequently than the larger batteries.

Thanks for your reply. Few Q’s to get my head around this. 

3 hours ago, Chriull said:

Max lift cut off speed depends directly on the battery voltage - with 100% charge one has 84V (4.2V*20=84V) versus 3.3V*20=66V with 0% charge. So the safety margin goes down with lower battery charge.

Sorry, this kind of goes over my head. What is Max lift cut off speed?

 

3 hours ago, Chriull said:

And one main point from the higher capacities is, that they have 6(?8?) battery cells in parallel and the smaller ones "just" 4. So they cannot deliver as much current (==torque) in peak burden situations, and in peak burden situations they have a higher voltage sag == less speed/safety margin available.

And what is a peak burden situation?

Thanks again 

[meepmeepmayer]

You won't feel any performance difference between battery sizes. Top speed is also the same. How a wheel behaves depends on the wheel. You'll only find a difference in batteries if you overlean a small battery where a bigger battery would have worked, but before that, it's all the same.

The power (as needed for sudden acceleration or a sudden bump) is the product of voltage and current.

The voltage is temporarily constant, it is whatever the battery voltage (depending on charge state), including the voltage drop from stressing the battery, is.

The max current depends on how the battery is built. Batteries are made from multiple parallel blocks of a fixed number of cells in series. The more parallel blocks you have, the higher the max current. So a 6p battery (6 blocks in parallel) has a 50% higher max current (and therefore max power) than a 4p battery. You get about 10A continuous and 20A peak per block.

So more "p"s means more peak power of a wheel. "Bigger" battery means more p's.

In practice, we found that:

• 1p = death. Well, not that bad, but only good for really slow learner wheels. Example wheel: KS14M 174Wh or anything below 200Wh.
• 2p batteries are borderline unsafe from a modern point of view, unless for slower wheels and lighter riders. E.g. Inmotion V8.
• 3p batteries are fine, but I wouldn't want to run a performance wheel with it. E.g. MCM5 84V, mten3.
• People ride 4p performance wheels all the time and don't overlean them. E.g. Tesla, 18L, V10(F), ... 
• 6p and more is of course nicer and awesome, but 4p seems to be the cutoff to "totally fine even for the extreme wheels".

For the battery options you mentioned:

• 84V 800Wh is 3p (20s3p - 20 cells in series for 84V, 3 blocks of those) with 3450mAh cells: 20 * 3 *3.7V[nominal cell voltage] * 3450mAh = 766Wh (= 800Wh in marketing speak).
• 84V 1600Wh is two battery packs of those. So 6p. The 800Wh version has one pack in the wheel on one side, the 1600Wh has two packs on both sides.
• 84V 1300Wh is also 6p, but using two 650Wh 3p packs (2900mAh per cell) instead of two 800Wh packs.
• 100V 1230Wh is 4p (24s4p with 3450mAh cells).

I'd be slightly (really only very slightly) concerned with the 3p 800Wh MSX (mostly at very high speeds), but that's about it.

Edited June 20, 2019 by meepmeepmayer

[RoCan]

3 hours ago, Daniel-Son said:

It seems to me if you are happy with the range of the MSV3/680WH,  you should be happy with the MSX/800WH. Then you can save some money. But if I can  squeeze a little more money, I would get 1300WH, that’s 500WH more than the 800. 

Any MSX is going to give you the oomph that you need, it just a matter of how long you want to ride. 

Thanks for your input. This is my thinking but just want to make sure I’m not going to  miss out on any extra performance.

[RoCan]

3 hours ago, Rywokast said:

yes as stated the msx will absolutely give you a lot more torque and raw power than the V3S no contest there and if its 680 and fine then i guess 800 should be ok for you,, like i said 800 or 1600 there will be no power difference, its just obv the bigger battery will give you 100% performance for a lot longer.. but remember like I said the msx is not so kind on the battery, it's a power hungry machine with is raw power, torque, and fat tire don't expect the battery increase to be linear.. an msx 800 would likely be good for as long as the v3s 680.. if you can I would really recommend springing for the 1300.. from what it sounds like you like to do, that type of riding is much harder on the battery even at 20 kph than it would be going 30 kph steady on tarmac.. speeding up and slowing down a lot especially from stand still are what eat up the battery the most relatively, not cruising at an average speed.. but at least you have something to compare it against, if the 680 is more than good enough for you and you're certain, then the 800 will be absolutely fine.. maybe it's just me but whenever I get on a wheel I don't want to get off until the battery runs out haha it's like an addiction

Thanks for this. Good insights. If my feet would allow I would stay on the wheel longer but I think this will come with time. My legs are definitely willing after a whole load of squats. 

I’m starting to think I should listen to you experienced folk with a bigger battery as it would be very annoying to outgrow an MSX once my stamina is at a maximum. 1600wh would also be better for resale I think.

[RoCan]

14 minutes ago, meepmeepmayer said:

You won't feel any performance difference between battery sizes. Top speed is also the same. How a wheel behaves depends on the wheel. You'll only find a difference in batteries if you overlean a small battery where a bigger battery would have worked, but before that, it's all the same.

The power (as needed for sudden acceleration or a sudden bump) is the product of voltage and current.

The voltage is temporarily constant, it is whatever the battery voltage (depending on charge state), including the voltage drop from stressing the battery, is.

The max current depends on how the battery is built. Batteries are made from multiple parallel blocks of a fixed number of cells in series. The more parallel blocks you have, the higher the max current. So a 6p battery (6 blocks in parallel) has a 50% higher max current (and therefore max power) than a 4p battery. You get about 10A continuous and 20A peak per block.

So more "p"s means more peak power of a wheel. "Bigger" battery means more p's.

In practice, we found that:

• 1p = death. Well, not that bad, but only good for really slow learner wheels. Example wheel: KS14M 174Wh or anything below 200Wh.
• 2p batteries are borderline unsafe from a modern point of view, unless for slower wheels and lighter riders. E.g. Inmotion V8.
• 3p batteries are fine, but I wouldn't want to run a performance wheel with it. E.g. MCM5 84V, mten3.
• People ride 4p performance wheels all the time and don't overlean them. E.g. Tesla, 18L, V10(F), ... 
• 6p and more is of course nicer and awesome, but 4p seems to be the cutoff to "totally fine".

For the battery options you mentioned:

• 84V 800Wh is 3p (20s3p - 20 cells in series for 84V, 3 blocks of those) with 3450mAh cells: 20 * 3 *3.7V[nominal cell voltage] * 3450mAh = 766Wh (= 800Wh in marketing speak).
• 84V 1600Wh is two battery packs of those. So 6p. The 800Wh version has one pack in the wheel on one side, the 1600Wh has two packs on both sides.
• 84V 1300Wh is also 6p, but using two 650Wh 3p packs (2900mAh per cell) instead of two 800Wh packs.
• 100V 1230Wh is 4p (24s4p with 3450mAh cells).

I'd be slightly concerned with the 3p 800Wh MSX, but that's about it.

Brilliant info thanks!  This has clarified my thoughts.

I guess just one more question which I think has been covered elsewhere. Is there a noticeable increase in torque with the 100V version?

[meepmeepmayer]

30 minutes ago, RoCan said:

Is there a noticeable increase in torque with the 100V version?

In theory, in motor construction (which is independent of battery pack configuration) you have a trade-off between top speed and torque. Higher voltage gives you more top speed and less torque, while lower voltage gives you more torque and less top speed. So higher voltage isn't automatically better.

In practice, there seems to be little difference between the 84V and 100V MSX, but the 84V apparently has a small torque advantage:

Edited June 20, 2019 by meepmeepmayer

[Rywokast]

10 hours ago, RoCan said:

Brilliant info thanks!  This has clarified my thoughts.

I guess just one more question which I think has been covered elsewhere. Is there a noticeable increase in torque with the 100V version?

100V is a waste of money for 99% of people.. youre paying more for less batteries and the same or less torque, you need a special charger, resale value will suck, all that for what 5-10 max kph top speed increase?? the top speed of the msx is like 62 already lmao, if you ONLY care about top speed and find yourself constantly wanting more than 60 kph then get the 100V.. everyone else its a complete waste of money

Edited June 20, 2019 by Rywokast

[RoCan]

Thanks to all the reply’s on this.

I’ve just bought the 84V 1600wh! Whoop! So excited!  (got to love PayPal credit)

It was actually only £200 more than the 800wh so a no brainier in the end and should see me through at least 2 years (or until something better comes along) with better resale also.

Now just hoping this sale is all genuine as it’s cheaper than Aliexpress and shipping from Europe so almost too good to be true. £1239. I’ll post back once received.

Thanks again 

[stephen]

2 hours ago, RoCan said:

Thanks to all the reply’s on this.

I’ve just bought the 84V 1600wh! Whoop! So excited!  (got to love PayPal credit)

It was actually only £200 more than the 800wh so a no brainier in the end and should see me through at least 2 years (or until something better comes along) with better resale also.

Now just hoping this sale is all genuine as it’s cheaper than Aliexpress and shipping from Europe so almost too good to be true. £1239. I’ll post back once received.

Thanks again 

Congratulations on your purchase , where did you buy it from? 

Your going to love the range 😊👍

[Rywokast]

2 hours ago, RoCan said:

Thanks to all the reply’s on this.

I’ve just bought the 84V 1600wh! Whoop! So excited!  (got to love PayPal credit)

It was actually only £200 more than the 800wh so a no brainier in the end and should see me through at least 2 years (or until something better comes along) with better resale also.

Now just hoping this sale is all genuine as it’s cheaper than Aliexpress and shipping from Europe so almost too good to be true. £1239. I’ll post back once received.

Thanks again 

200 more?? thats a no brainer!! your resale value alone would more than cover that cost, not to mention youd be able to use that battery if you wanted again for future eucs and you will be able to ride as hard as you want for hours at a time  good choice

[Daniel-Son]

Excellent! Now you’re part of the Big Boys Club!

[RoCan]

2 hours ago, stephen said:

Congratulations on your purchase , where did you buy it from? 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F183850492003

They have the same advert up 4/5 times with 2 different prices so until I receive it, I’m not 100% convinced.

[RoCan]

34 minutes ago, RoCan said:

They have the same advert up 4/5 times with 2 different prices so until I receive it, I’m not 100% convinced.

Actually just noticed it’s 4 different sellers but all their adverts look the same and went live at the same time. Bit weird.

[Ben Kim]

Well, my 18S is now a 16s8p, and I finally stretched its legs out today, went 30.4 miles non-stop with 44% battery left.  I didn't even once get tilted back.  Given I have never tried an 84V wheel or a 100V for that matter, ignorance is bliss.  I found this wheel to be sufficiently fast enough for my needs.  I've gotten it up to 29.5 MPH as well which is no small feat from what I've heard on this wheel.  

 

[mrelwood]

On 6/21/2019 at 10:00 AM, RoCan said:

I’ve just bought the 84V 1600wh! 

You absolutely made the right choice! Either your feet will get stronger or you will find shoes that help you last better, which is when a 800Wh MSX would suck a bit.

I’ve ridden the 1600Wh MSX since last July, and I’m seriously considering upgrading the battery to 2100Wh... 

[stephen]

1 hour ago, mrelwood said:

 

I’ve ridden the 1600Wh MSX since last July, and I’m seriously considering upgrading the battery to 2100Wh... 

I wish i knew someone who could do mine,, what do i need 😊 i suppose a shop could do it

[RoCan]

1 hour ago, mrelwood said:

You absolutely made the right choice! Either your feet will get stronger or you will find shoes that help you last better, which is when a 800Wh MSX would suck a bit.

I’ve ridden the 1600Wh MSX since last July, and I’m seriously considering upgrading the battery to 2100Wh... 

It arrives today! Hopefully as advertised.

I am 100% sure the 1600wh is the right choice. If I’m not using full range just yet it will save me charging daily, not to mention the other benefits discussed above.

I’ve also just discovered some new trails that are car width and long! It means I can unleash the beast without worrying about dog walkers popping up around a corner. So my mileage per ride is likely to go up pretty quickly. Most trails around here are single track walking routes which although fun, limit the speed.

Would an extra 500wh require a rewire of the existing batteries or can you just add a pack? I presume there’s space inside?

[stephen]

1 hour ago, RoCan said:

Would an extra 500wh require a rewire of the existing batteries or can you just add a pack? I presume there’s space inside?

I'd like to know this too😊