That LiitoKala battery, first use (maybe a thread to keep logging range)

[Manc44]

This is the 48V LiitoKala battery, advertised as 25Ah. The pack uses their own 21700 cells that are advertised as 5,000mAh.

First time ever using it, today on a fresh charge I went 10.82 miles and the battery voltage went from 54.6V to 49.5V, with it saying it used 28% of the battery, which if the shutoff is 37.4V like the page selling it states, that 28% used pretty much ties in with the percentage of voltage used before it gets to the shutoff point.

I worked that out to be a range of about 38 miles if the last 72% runs out the same way the first 28% did, which I can only know by running it down to the 36.4V (+/- 1V) shutoff point.

Yes that's not a lot for a 25Ah is it... but I put out about 50W myself, this was (deliberately) a hillier than average ride, hammering the max PAS level a great deal, on throttle only. In fact I'd estimate I probably didn't even ride half a mile under my own steam lol.

The motor got slightly warm but not hot, same with the controller.

The difference this thing makes is insane. I normally go up that 11% gradient in my 22x32 gear (17.6" gear inches) and even in that gear, I can't do it without stopping and my heart rate getting above 175 or 180, around it's max. The thing is whenever I do that, it's so tough I just get really disheartened and I actually stopped biking for a while wondering what to do. This is why I got a motor - to go places and enjoy the scenery, hell maybe actually get to the top of a hill every now and again without it nearly killing me.

On that same hill today I was casually riding up it only exerting myself slightly and was in the gear 36x28 (33" gear inches). The granny ring has suddenly become redundant, unless the battery runs out, which is why I got a hub as opposed to mid-drive. Give up my triple? From my cold dead hands!

I'm happy with this if it gets 38 miles of range doing rides like I did today - it was extra hilly on purpose to see how much it drains the battery. Normally I'd just keep it on PAS 1 or 2 out of 5 and while there would be hills including long ones, they wouldn't be 11% gradients or anywhere near that.

At one point it was pulling 850 Watts lol... with me on throttle only on about a 12% gradient. It can't actually keep that up and I ended up going about 3 MPH with it slowing more and more. When I put a little effort in, it dropped to about 800W, so I guess my input was about 50W. Mark Cavendish, I am not!

 

[vfr400]

You can't calculate the range like that. I would estimate that your capacity was 40% down at that voltage. The only way to be sure is to use a wattmeter and run the battery all the way down once.

 

[wheeliepete]

I don't think you will run the battery down to 37.4v even if the BMS allows this as the LVC in the controller will cut in around 40v.

 

[Manc44]

Cheers folks.

Edit: There's only one way the throttle and PAS can be connected, scrap the previous stuff about swapping them (and it was off-topic).

 

[Nealh]

37.4v is a very deep discharge the cells would be under 2.9v.

 

[Manc44]

I used to have a 24V/8.8Ah battery back in 2014 and I know I got 12 miles from that battery, so I made an Excel calc where I can input the battery Volts, the Ah and the Wh Per Mile. Well actually the Wh Per Mile part is something I juggled around until I got it to say 12 miles. It was only 17.5Wh per mile which I thought was good going!

So if I know I used 17.5Wh per mile on that setup, I can figure it out for a new battery on this calc, by changing the old 24V to the new battery at 48V, then changing the 8.8Ah of the old battery to the (estimated) 21.3Ah of the new one... the result comes out to 58.42 miles.

I know I won't get that though because I am about 40lbs heavier, my bike is about 40lbs (not 20lbs) and my new battery pack is about 3 times heavier than the old one was. Added to this is the fact that I was on skinny tyres at 90 psi and these days I'm on fatter ones at 60 psi. I have no idea how that might affect things.

I also don't know how it might affect things having one power level on that kit in 2014, compared to now having 5 levels. I am pretty sure the speed I went on that old 24V kit is roughly the speed I now get on level 1 on the new 48V setup, perhaps the 24V went about 12.5 MPH and this new kit goes about 11 MPH on level 1.

The only way to know is to do a lot of testing, I mean perhaps leave it on level 1 for an entire battery cycle, then try it on level 2 for an entire cycle and test all 5 levels that way.

Today I got my PAS extension cable so I can just pedal now to test it, which is way more convenient than using the throttle - although the "always on" aspect of the PAS is something I don't like and I have set it up so I can just unplug it and tuck the plugs away while out riding if I don't always want assistance 100% of the time - which is inescapable if the PAS is plugged in.

What would be good is a switch along the PAS cable or even better, a switch on the handlebars for it. People argue over what's best, PAS or throttle... I don't get into the arguments because I use both!

Here is the calc if anyone might find it useful:

https://www.dropbox.com/s/ytg8d5fb0jmy3hk/eBike%20Battery%20Range.zip?dl=1

 

[Nealh]

17.5wh/m is quite a heavy rate to use but if one is very unfit or has a disability then it might be a fair figure to use. For a regular or a fit person who rides quite often the 8 - 12 wh/m is a more likely accurate figure which would certainly give more range.

 

[wheeliepete]

Can you not just swich the system off, rather than unplugging the PAS? assuming you have a display of some sort.

 

[Manc44]

17.5wh/m is quite a heavy rate to use but if one is very unfit or has a disability then it might be a fair figure to use. For a regular or a fit person who rides quite often the 8 - 12 wh/m is a more likely accurate figure which would certainly give more range.

I hammer the motor though lol. I need to get back to those fitness levels again.

I'm almost certainly using more than that now. I know I must be, because I was using 17.5wh/m on a carbon road bike, 25c tyres at 90 psi and I weighed about 155lbs back then, compared to now on a metal MTB with 1.75" tyres at 60 psi with me weighing about 195lbs.

Can you not just swich the system off, rather than unplugging the PAS? assuming you have a display of some sort.

I can, by just lowering the power level to zero - but then the throttle is also off and this is the problem. If the PAS had a switch I could just flick that switch and the throttle would still be working.

It's something the kit makers might consider adding if enough people ask for it. A switch on the PAS wire can't cost much. Also some padding for the controller in the case, the outside of that case and a PAS extension cable, maybe some disc rotor spacers, more hub washers.... lol they could add quite a few things to it. These are all things I had to buy to use the kit.

Carrying on with the battery capacity testing...
Today I am going to get a 14.2 mile ride done on it, hammering the motor again (this time with PAS on since I just put a JULET extension cable on to make it usable) so after that, adding the other 10.8 mile ride, it will have done exactly 25 miles. Right now after 10.8 miles the battery is reading 73% left after a full charge. Having the PAS on I think I'll try to stay out of levels 4 and 5 (out of 5) because it's probably going to use more battery than throttle was, although that's on/off all the time, again possibly zapping battery power over a PAS that's always on?!

Something that surprised me about using this kit, I can start up a steep hill on the max power level, then pedal and I'm going about 8-10 MPH with the motor using about 800W. If I lower the power level down to 1 it's still using 800W and I'm still going the same speed up the hill! That's crazy to me, but I guess it's just the motor is trying its hardest on all power levels - with the only difference being that you'll go faster on higher power levels if the motor is capable of doing it. I prefer it this way because I could just leave it on level 1 and I know I'm still going to get enough power up steep hills.

 

[wheeliepete]

Blimey, maybe they could add a little army of androids to fit it as well I've never heard anyone wanting a switch on their PAS, but easy enough to do yourself by cutting into the 5v wire, usually the red one.

 

[vfr400]

Something that surprised me about using this kit, I can start up a steep hill on the max power level, then pedal and I'm going about 8-10 MPH with the motor using about 800W. If I lower the power level down to 1 it's still using 800W and I'm still going the same speed up the hill!

Your controller is using speed control rather than power control. Under speed control, you get full power in each level with a different max speed in each level, so going slowly up a hill, it'll make no difference which level you select.

Which controller do you have? If it's a KT one, you can change it to power control in the settings, where you get the same max speed in every level, but a different amount of power.

 

[Manc44]

Your controller is using speed control rather than power control. Under speed control, you get full power in each level with a different max speed in each level, so going slowly up a hill, it'll make no difference which level you select.

Which controller do you have? If it's a KT one, you can change it to power control in the settings, where you get the same max speed in every level, but a different amount of power.

It's a YCSV126-001-48T that came with the kit. To be honest I think I'd prefer it staying the way it is, although if I get this purported "kick" from the PAS people have claimed happens with this particular controller, I might end up swapping it out for a KT, assuming all the wires have all the right plugs on. It's got a male XT60 for the battery on this one I've got and a lot of the KT ones I looked at have a different one. I know you're going to say it's easy to solder whatever you want on but it's easy for you vfr400, it's not easy for me the chances of me shorting and knackering the battery are like, in the high 90's%.

 

[Manc44]

Done 2 rides up to now, here's the details and the battery power it says it has left, in volts and as a percentage.

It started out on 100% charge at 54.6v on a fresh battery, left on charge for 12 hours first time charging it, to allow for cell balancing (if it was doing it, I have no idea, but it's a brand new battery anyway).

Ride 1:
Distance: 10.8 miles (17.38 Km)
Combined elevations: 444 Meters
All elevations average gradient: 2.55%
Battery voltage: 49.5v
Battery percent remaining: 73%

Ride 2:
Distance: 4.2 miles (6.76 Km)
Combined elevations: 63 Meters
All elevations average gradient: 0.93%
Battery voltage: 48.6v
Battery percent remaining: 65%

Ride 1 used 2.5% of the battery per mile.
Ride 2 used 1.9% of the battery per mile.

That ties in with how hilly the 1st ride was (mile for mile) compared to the 2nd. The average gradient was far higher on the first ride so this makes sense.

Sorry guys, I was meant to do a 14.2 mile ride on that 2nd ride, to make it a round 25 miles but the above 2 rides only add up to 15 miles. I just didn't have the time to fit it in.

Tomorrow I will do a 15 mile ride and hopefully the battery will last, at least for that. Up to now, I have used the first 35% of the battery doing 15 miles. Can the other 65% get me another 15 miles? I'll find out when I do it

Tonight on the 4.2 mile ride I was again hammering it quite a lot on max PAS level. The first ride was more hilly than I would typically be doing, so these mileages are going to be on the low side compared to an average IMO.

Here's how I am keeping track of it all:



The "Effort" figures are just so I can compare one ride to another. It doesn't actually mean anything on it's own as a unit of measurement - it's the average gradient for that ride, multiplied by the miles.

Here's what it all means:

Hills (Meters) = every hill in meters on the ride, added together, making sure it's the difference from the bottom of the hill to the top, since I live about 105 meters above sea level already.

Gradient = The average gradient for that ride based on hills and distance.

Effort = Gradient multiplied by distance (Km).

Diff V = Battery voltage drop since last ride.

Diff % = Battery percentage drop since last ride.

%/PM = Battery percentage used per mile.

Tot Miles = The ride distances when added together.

This should keep a good record of what the battery is capable of and how it performs on hilly Vs flatter rides.

I got a 15 mile ride penciled in for tomorrow (if I can be arsed!) that will take the total usage up to 30 miles on this charge. If it keeps using the battery percentage at the same rate as the short 2nd ride then in theory there might be about 34 miles left in the tank. Doing about 15 miles should safeguard against it not managing to do those 15 miles, let's see. If I post at 1AM tomorrow it's because it ran out and I was averaging 8 MPH (as opposed to 15 MPH with the motor)

EDIT: A few of my hill figures were off, this is right. It's getting complicated lol...



... using 25Wh/mile on that first ride is because about 1.5 miles of it was up a 12% incline and I wasn't trying much. The second ride I was hammering it on max PAS level for nearly all of it. The third ride hasn't been done yet hence the lack of battery results. The 21.3Ah is me guessing that's what my "25Ah" LiitoKala battery really is based on one guy saying he got 17Ah from his 20Ah battery - which I'm not taking 100% seriously since it's one guy, but I can easily change it, especially after a full cycle when it might be guessed at a bit better.

 

[Manc44]

Spreadsheet now has "Battery Potential" showing what you could get from the battery riding the same way as the ride it corresponds with on that row.

I have uploaded a template version of this spreadsheet if anyone thinks they might get some use out of it. It's complicated though, only I know what's what on it. Also it can easily get messed up! Only the yellow boxes get filled in, the green boxes show results. Totting up the hill elevations probably isn't something most people know how to do, or could be arsed bothering to, but if anyone wants to try it, it's linked to below, with some fictitious rides that can be changed or whatever.



Here is it, good luck with it

https://www.dropbox.com/s/64lvnttmk1f9d7b/Ride%20Diary%20%28eBike%29%20-%20TEMPLATE.7z?dl=1

The above download has fictitious locations and figures put in, you can change, delete etc...

 

[vfr400]

I already told you that 48v is not the half-way point in terms of charge in the battery in the battery. Also, there are two factors increase the depletion as the battery empties. Firstly, you need to turn up the power at the end of the ride to get it the same as at the beginning of the ride; secondly, the battery voltage goes down faster as a basic characteristic of the battery

Your battery goes from approx 54v to 42v. 48v is half way in value. Say you were riding with a constant current of 5 amps throughout your ride to deplete the battery. You would have used up 255wh when your battery shows 48v - from (54-48)/2 x 5, but there would only be (48-42)/2 x5 = 225wh remaining, which would make a total of 480wh, and the split would be 53% and 47% .

That's if the voltage went down in a straight line, but it doesn't. Once past 48v, it will start to accelerate downwards, so the true split is closer to 60%/40%.

Finally, the watts at the beginning would be 54v x 5A = 270w, but at the end of the ride, they'd only be 42v x 5A = 210w. In practice, you'd be turning up the power at the ned of the ride to get the same as at the beginning. To get the same assistance, you'd need 6.4 amps. The higher current would drain the battery faster too.

 

[Deleted member 16246]

@Manc44 - You might be over thinking this a bit.

Do a long ride. See how much is left. Charge. Remember.

 

[Manc44]

vfr400 that 48v figure is only there so the calc can multiply it by Ah to get Wh.

The other "Volts?" figure under "Battery Power Left" is what you enter based on what your display says the voltage left is. If the voltage drops faster when it goes under 50%, that will end up being reflected on the spreadsheet once a complete battery cycle is filled in. In fact you'd then know if it's 53%/47% or 60%/40% or however it turns out. Then you can just name that spreadsheet "Cycle 1" and start a new one.

 

[Manc44]

Just did a ride on PAS 2 (out of 5) and what a difference that made to the efficiency, compared to the first two rides hammering it!

I have ended up taking the throttle off completely, since I can't imagine ever using it now the PAS is setup, but it means my left shifter can work properly again and I get to have my comfy grips back on, along with taking away the risk of accidentally twisting the throttle.

I can see my 11/13/15t sprockets getting worn damn fast with this motor on!

Latest ride, this time strictly keeping it on PAS 2 all the way:

Distance: 8.19 Miles (13.18 Km)
Hills: 201 Meters
Average Gradient: 1.52%
Battery Voltage Drop: 1V (on a 48V system)
Battery Percentage Drop: 9%
Battery % Per Mile: 1.10%
Watt Hours Per Mile: 11.24 Wh
Battery Potential: 91 Miles

The battery now has 56% left, or 50%, or 40%, no 35%, maybe 32%

I don't know, that's why I am doing this and running it out.

I might do the exact same ride again next time and put it on PAS 3 to see what the efficiency difference is. I am really surprised and happy that simply by sticking to PAS 2 it's become so much more efficient. 11.24 Wh per mile! It was by no means a flat ride either.

I know this isn't accounting for the last 50% running out quicker but after a full battery cycle it will become clearer.

 

[Manc44]

It seems the more I use the battery the less it drops in voltage for the same distances. Tonight I repeated the exact same ride as the first ride (but on PAS 2 tonight when the first ride was on PAS 5) and it's coming up with what I think must be impossible (7.48 Wh/mile). This is on quite a hilly ride. I know I wasn't putting in that much effort!

My prediction is, this is rapidly going to drop in voltage on the next 15 mile ride I have planned, maybe with the battery running out while on the ride but hopefully when I'm nearly back home.

Here's the chart up to now, something's not right about that last entry, maybe my display is mis-reporting the true voltage, I don't know...

 

[vfr400]

It seems to more I use the battery the less it drops in voltage for the same distances. Tonight I repeated the exact same ride as the first ride (but on PAS 2 tonight when the first ride was on PAS 5) and it's coming up with what I think must be impossible (7.48 Wh/mile). This is on quite a hilly ride. I know I wasn't putting in that much effort!

My prediction is, this is rapidly going to drop in voltage on the next 15 mile ride I have planned, maybe with the battery running out while on the ride but hopefully when I'm nearly back home.

Here's the chart up to now, something's not right about that last entry, maybe my display is mis-reporting the true voltage, I don't know...

View attachment 43794

Something's a bit off with the logic in your worksheet. You've done 34 miles and used more than half of your battery. There's no way you're going to get 102 miles out of the second half unless you switch off the electrics and push it. I'm going to predict somewhere between 44 and 50 miles total of normal ebike riding. You can make it anything you want by turning off the power and pedalling hard, but what's the point. Once you get down to about 5wh per mile, a non-electric road bike becomes a better option because it's faster, doesn't need charging and needs a lot less maintenance.

can you feel the difference in motor power yet from when it was fully charged?