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

[Manc44]

I can't compare because I was all excited on the first couple of rides and had it on max PAS. My plan is to keep it on PAS 2 now until it runs out. Next ride will be 15 miles (or whatever makes it up to 50). After charging it fully next cycle, I will probably set it on PAS 3 for the whole cycle.

I don't believe for one second there could be 49% left in the tank but, it is theoretically a 1200 Wh battery so who knows.

If the power diminishes as the battery is used won't that get reflected in the average speeds? Well, if I stick to the same route and the wind is about the same.

I kept my trusty Cateye Velo on the bike and the trip distance and so on are taken from that, the Bafang P850C display doesn't let you set the wheel circumference in mm, it just has general wheel sizes in inches and, it always comes out with a trip distance slightly further than I really went, so the wheel is say 26" but it's turning more turns (as far as the display goes) as if it's a smaller wheel. It probably expects a 2.25" MTB tyre on a 26" rim, whereas my tyres are 1.75".

If I had a wider monitor I'd add "Bafang Distance" column and a "Real Distance" result column to the spreadsheet, it's getting like War and Peace as it is though.

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.

That "Battery Potential" refers to what you might get from a full charge, if you did every ride like that particular ride. It won't be completely accurate because of what you were saying about 60%/40% etc.

It's more off than that, look again, it's coming out with a 136 mile range lol, something's off and it's not my formulas in the spreadsheet because the line was simply copied from the one above.

As the battery drains more, it's reporting a higher voltage than what it seems like it should be.

 

[Manc44]

Just got another 15.69 miles under my belt or rather, my battery and motor has!

This battery is an absolute beast. I went an exact distance tonight to make the total mileage come out to 50 miles.

The first two rides I was hammering it on max PAS (5). On the last three rides I had it on PAS 2 the whole time (which is what I probably should have done from the beginning).

Does anyone know why, as I drain it more, the Wh per mile is getting better? It's not really getting better is it... I mean that's like some sort of false readout on the voltage and battery percentage? Although the ride tonight was both quite flat (as you can see from the gradient on the last ride) and I was on PAS 2 again.

I am expecting it to start weakening more from now until it's drained. It says 39% left which is ludicrous considering I only ever wanted a battery that could do 50 miles. It's done 50 miles hammering it on max PAS the first 15 miles of it and used 61% up. Just crazy.

Here's the spreadsheet up to now... I wonder how many more miles it's got left on it using it on PAS 2

 

[peter.c]

The voltage percent on the display is a wild guess -timate, the total miles from fully charged to cut off is the proof in the pudding, even the watts shown are only rough
the volts are more accurate but not as a decent multi meter that's calibrated
my 19.2 ah gets 60 miles + of hard use just ordered a pack to try
A rider who i see regularly gets 200 mile out of a 12ah battery but he only powers up about 15% of the time then only at low power rides the rest as a normal bike

 

[vfr400]

A rider who i see regularly gets 200 mile out of a 12ah battery but he only powers up about 15% of the time then only at low power rides the rest as a normal bike

This is the problem where posts like this can start to become misleading when people take things at face value instead of understanding what's going on.

A normal rider using a meaningful amount of assistance takes about 12 to 15 wh per mile. You can get any range from any battery by adjusting the assistance power and how hard you pedal. OP is now down to 6.52 wh/m. That says more about OP than the bike or battery. By the time you get down to 5wh per mile, you'd be better off on a road bike without all the hassle and weight of an electric one because 5wh per mile is about the power you need to drag around the extra weight of an electric bike compared with a road bike.

Manc44, I'm not saying you're doing anything wrong. I congratualte you on your determination to get fit by giving as much power as you can. I only mention the above because some people might see 157 miles potential range and think that's a feature of your bike/system instead of your own efforts.

 

[Manc44]

I'm really unfit though, it's up the wall IMO. Put it this way, before putting the kit on, I had to be on a 22t inner chainring and 40t sprocket (on 11-speed) and even in that low of a gear, I couldn't get up the 610 meters of 11.3% gradient near where I live, not without stopping anyway. Also, before putting the kit on, I had not even been on my bike for weeks and weeks, simply because of how knackering it was doing just 5 or 10 mile rides. That same hill I used to need 22x40 (14 gear inches) on, I can now get up with the motor in 36x28 (33 gear inches) which is about the same gear as the lowest gear used to be on my Decathlon Triban 3 road triple at 30x25 (31 gear inches).

Up most hills, the display says it's helping me with around 400W. On that 11.3% hill it says 850W. It assists with this amount on all PAS levels.

I added even more to the spreadsheet and it is saying the average of all those potential range figures is about 94 miles from a full charge, with the voltage cutoff estimated at 39.35V, but that's just averaged, I am getting different figures if I work it out for each ride, I guess because the first two rides were on PAS 5 with the rest on PAS 2.

The only direct comparison is the two rides that are 10.94 miles each, the first on PAS 5 (25.23 Wh/mile) and the second on PAS 2 (7.48 Wh/mile). That is a massive difference in Wh used considering it's the same exact route. Neither time had much wind. Does 3.37 times more Wh used sound remotely right just from PAS 2 to PAS 5?

After filling in so many details, the spreadsheet just isn't telling me much lol, only the real world mileage is going to prove anything.

I have the battery down at 21.3Ah although it's a 25Ah. I deliberately have it lower just because of a review where a guy said his LiitoKala 20Ah was giving him 17Ah.

I can see myself buying a battery 2/3 or even half this size and swapping to it, then saving this one for the odd epic ride here and there. I'm not carrying a 5KG battery around if there's no real need to! Then... I might be able to fit that smaller one where I originally wanted to have it, under my down tube. This 25Ah one is 11cm deep and with a suspension fork, it just won't fit there.

 

[vfr400]

A 36v KT controller allows around 60w on level 1 and 600w from the battery on level 5, so ten times the difference. It's proportionally more power for a 48v one because of the higher voltage. When I ride my electric MTB on level 1, I ride at the same speed and effort as my road bike except on downhills, where the road bike is considerably faster.

You can see from your data, that your journeys are taking longer and your average speed is going down. That's because you've been turning down the power and are pedalling harder.

 

[Manc44]

Cheers vfr400. I thought about a KT controller but if it was assisting with less power on the lower levels, I can see myself constantly pressing plus and minus all the time, whereas with it having the same on all levels, I never need to. This is why I put it on PAS 5 on that first (and hilly) ride - I just thought PAS 5 would be necessary up those 11% inclines, but no, it could be on PAS 1 and it still registers as 850W when going up that same steep hill. I think I prefer it this way, because I can just put it on PAS 2 and leave it. One thing I just don't care about is going fast and the 13.5 MPH it's doing now is perfect, especially if it means getting a lot more range.

The first 60% of the battery has got me 50 miles. Let's see what the remaining 40% does - bearing in mind that PAS 5 was being used initially, so it's not a consistent test and on a full charge on PAS 2 all the time, it would have a better range than whatever this is going to end up being when it finally cuts out.

Last night on that 15.7 mile ride, I set off with it on about 50% battery and by the end of the 15.7 miles it was on 40%. At times though up the steeper hills, the display said 25% battery left and it's while this is happening the voltage is also presumably reading lower too - so it seems to me, when it finally cuts out, it's going to do it on a hill where, there wasn't a need to cut out, it's just going to do it because there's a lot of power being used at the time?

Or is the percentage and voltage merely an estimation based on usage and it doesn't cause a premature cutout? I mean the voltage drop isn't real because I can get back on flat roads again and the voltage/percentage almost (or does) go back up to where it was again. As soon as I was up the hill, the 25% it was saying went back to 45% again. The quirks these things have lol.

 

[vfr400]

The only significant factor that affects range is how hard you pedal. Your controller uses speed control, so you get max power at start up, but level 1 has a max speed of something like 8 mph. Any time you're pedalling over 8 mph, you get no assistance. By turning down the PAS level, you're making it so that you have to pedal without power more of the time. If you turn it down to level zero, you get infinite range from the battery.

It really is very simple. You have say 1022wh in the battery to help you with your rides. How you use it is up to you. You can get a lot of help and use it up quickly or you can trickle it out with not much assistance and last it for a long time, or anything in between. As examples, You can use 1kw for an hour, 250w for 4 hours, 100w for 10 hours or 50w for 20 hours. The assistaance you get form that would be about 65% of those powers due to conversion losses, so 65w assistance for 10 hours, which is about where you are in your last ride.

 

[Manc44]

It didn't go much further than those 50 miles!

It cut off due to voltage sag up that 11.3% hill. At the time it was giving me between 800W to 850W.

When setting off, the 48V battery was at 45.3V. I set off along a flat road and, although the display said 40% in my house, when riding on the flat it said 25%. I set off up the offending hill and it did get part way up, probably about 400M of the 600M, but then I saw the battery percentage was nothing more than a red border with "0%" reading on it!

So it would seem that hill made it shut off and the approximate range of this battery is going to be around 50 miles. Since I hammered it on max PAS for the first 15 miles of those 50, with the following 35 miles of the 50 using more than three times less Wh/mile, I'd estimate the range (only using PAS 2) to be at least 50 miles, maybe up to 80 miles - because the first 15 of the 50 miles tripled is 45 then add the other 35 of the 50 to that = 80).

I still don't know what the range is if just using PAS 2 all the time, I need to charge it now and start again, making sure to leave it on PAS 2. It's going to be somewhere between 50 and 80 miles IMO. That's good to know - that the minimum range I wanted all along was 50 miles and, being stingy with the PAS, it's the minimum it will do.

I found this elsewhere:

"Once you hit about 44V on your 48V battery, you should consider yourself low on battery and start “limping” home using minimal power to reduce the voltage sag to avoid hitting the low voltage protection"

I set off with it reading 45.3V but, I guess if it was nearly fully depleted, that first hill (before the killer one) could have taken it down to 44V and then, I would be setting off up the nasty hill on 44V, thus making it sag from 44V and down, triggering the cutoff.

Now I need to charge it and I'm going to have to do something pretty funny to work out the capacity - I am setting up an old laptop, with a microphone plugged in and resting right next to the fan on the charger - because when that fan goes off, it's done charging, so I can record the audio and look at the sound file, trim off the silence at the start and end and see how many hours it was recording the fan. It's not the best way but it will work lol... then it's simply a case of 2A x the hours = capacity. Let's see how many Ah this thing really is.

The final spreadsheet... question marks are under those last boxes because I don't know the exact figures so I guessed at what percentage/volts it would have used on this (very short but steep) ride...



Voltage cutoff is a guess based on the percentage of battery it was using and the voltage drop occurring from it, but I think that's probably quite accurate at 39.24V. Maybe it's 39V. I wish I knew but this controller "YCSV126-001-48T" doesn't have much info about it anywhere afaik. EDIT: This says 39V (+/-1V)

Greenergia Hub Motor Controller 48V/36V 14-23A Fit 250W-1000W Electric Bike Brushless Hub Motor Ebike Conversion Kit Accessories for Bafang Rear and Front Motor 250W 350W 500W 750W 1000W

Greenergia Hub Motor Controller 48V/36V 14-23A Fit 250W-1000W Electric Bike Brushless Hub Motor Ebike Conversion Kit Accessories for Bafang Rear and Front Motor 250W 350W 500W 750W 1000W

www.interviewcost.com

It does also have a BMS, so that could have been what cut it off.

If I don't post again it's because my house set on fire charging it.

EDIT: Got it to turn back on and it says 35% battery left @ 44.8V. Of course if I started riding it even on a flat road, that percentage would sag to 25% or less. Everything seems about normal with it. At least now I know in future, when it gets down to about 45V, charge it.

 

[Manc44]

I made a charge calculator now

For estimating how long is left...



I still need to add something like "Charge Amps?" and if you fill that in, it can tell you the estimated true Ah capacity of your battery.

Note that when the above says it's 79.59% charged, my display wrongly says 94% charged due to the real voltage cutoff being way higher than 39V (more like 45V) due to sag when hammering it down at that last bit of poke the battery has left. Now I realise why people say don't look at the battery percentage on your display, look at the voltage.

In Excel I couldn't work out how to input the time in hours and minutes so it has to be in minutes which is a bit of a bummer but it all works. After 9h charging, it's estimating 2h 18m left, which makes it about 11h 20m to charge, which at 2A makes it a 22.4 Ah pack (sold as 25 Ah).

It's now at that point where it's topping off so I guess it might take a bit longer to actually finish up? I think putting the above figures in the calc after about 9h like I did is the best way to judge it, because the topping off part probably hasn't started that might skew it, whereas at 9h it shouldn't and it probably is something like a 22.5 Ah pack. That's not the 25 Ah it's sold as but I knew it wouldn't be, it's still more than the 21.3 Ah I was predicting. What do you want for £215 it's dirt cheap in reality. It would be even if it was a 17.5 Ah pack lol.

EDIT: Done it...



EDIT 2: Added even more... probably finished now lol...



Here to download...

https://www.dropbox.com/s/ikz7ns12t2pueg3/Battery%20Charging%20Calc.zip?dl=1

 

[Nealh]

I get lvc down to 38v with my 44v battery and approx. 41.6 for my 48v if I need to.

44.8v would be a get me home or limp home voltage using only low power, but with speed control there is no such low power as all levels give max current until you exceed the set speed in each assist. Where as my KT's do give low power and typically 80 -100w in PAS 1.

 

[Manc44]

Nealh I never thought of that with the KT controllers. I still don't want one though.

One off putting thing about my controller though, is it's on sale for $20.

The battery just completed it's first full charge, taking 11h 23m (at 2A).

I don't know how any topping off at the end of charging might skew this but it comes out to be 22.8 Ah / 1093 Wh. Close enough for me, to the advertised 25 Ah and probably enough to guarantee a 50 mile range on PAS 2.

Now this time, I am going to leave it on PAS 2 all the time, but I added my throttle back again (just for times I might have left it in a high gear on a hill start) and, when that's there it's tempting to use it but I'll try my hardest not to!

I want to do a complete cycle now on PAS 2 and then I'll pretty much know what the real range is, because the truth is I'm probably never going to use it on any other pow... I mean speed level.

The last spreadsheet was messed up with duplicated "Percent Left" on it, my bad.

Final charging spreadsheet after filling in the complete charge... it actually ended up at 54.4V (not 54.6V) but I put 54.6V just to make the figures come out right (and I don't like it claiming there's time left to charge when I know it's all unplugged and completed haha)...

 

[vfr400]

That's pretty good for the price. What was the total cost including shipping and duty?

 

[Manc44]

That's pretty good for the price. What was the total cost including shipping and duty?

£215.

Here's two identical routes both done from a full charge, but the first was on PAS 5 (max) and the second was on PAS 2. It used about 27 Wh/mile on PAS 5 and 16 WH/mile on PAS 2...



I'm sure getting the exercise in trying to do all this testing lol

That PAS 2 above was the first ride after the latest charge, I am going to leave it on PAS 2 the whole time and see what mileage it does.

After that, I am going to increase it to PAS 3 and do a full cycle on that setting.

PAS 1? 4? 5? Meh, not bothered. I think 2 and 3 is the sweet spot. Efficiency is all I am bothered about.

 

[Manc44]

I've not completed a full cycle on PAS 2 yet but I think this is pretty close:



That is the true Ah (it took 11.38h to charge at 2A) and the Wh/mile might be a little off, it needs a full cycle doing, but then I don't need a calc, I'd just know what mileage it has done lol, the (other) calc is attempting to work it out as the battery gets used.

 

[Manc44]

Folks, how come on a fresh charge I can use the first 30% of the battery doing a 15 mile ride, then I can repeat that same 15 mile ride starting at 70% battery left and it only uses say 10% or 15%?

I know the display can't accurately determine the percentage left but it's pretty far out. My cutoff is about 40% due to voltage sag so I take that 60% of usable percentage to mean 100% in reality.

In other words, I have 60% of usable battery percentage - where the first 30% (100%-70%) is taken off by doing a 15 mile ride, but then it takes another 35 miles to make it go from 70% down to 40%.

Same with voltage, but I know I'm nearing the end at 45V (on a 48V) system despite the cutoff being 39V, because of voltage sag, OK I get all of that, I just wondered why the percentage displayed is pretty much useless lol, I mean as long as I remember that 40% left really means zero left then yeah it's fine.

I'm not complaining, I still really get about 50 miles from this pack which is about what I wanted to be able to get.

Here's something quite surprising I found - it seems the range when using PAS 2 is not increased over using PAS 5. I guess at PAS 2 it's using the motor for longer because it's going slower but I was convinced that meant more efficiency... it seems not.

I still need to do more testing but this 2nd cycle is nearly complete and I've been on PAS 2 the whole time. If anything it's possibly done less mileage than last time when I had it on PAS 5 for the first 15 miles.

The calc spreadsheet has just got more and more complicated (despite removing hill elevations) but I know what's what with it. There's numerous reasons these range figures might be lower than what the pack might do for someone else using the same pack. I'm lazy as hell and don't push all that hard when pedaling, I'm about 195lb, I'm on a bike that's about 70lb, I go up really steep hills every other ride (last night I went up one that's an average of 13% for 500M) etc etc. I should think that without all of that, the 50 mile range I can get from this could be 80 miles or more for someone else, that doesn't go up these sorts of gradients.

Anyway the latest chart...



That middle "ride" wasn't a ride, I had the bike upside down on PAS 5 deliberately pulling the brakes to get the pads parallel because they were rubbing after a cassette swap... a 32t isn't needed anymore, in fact I'm getting away with my 36t middle chainring and 21t at the back but, it just needs to be a 23t I think to avoid ever using the granny. That gear (36x23) can get me up a 13% gradient, which is insane to me and shows the huge difference made by having a motor. It's like having two Lance Armstrongs helping out (literally, 2 x 400W). It's probably the best thing I have ever bought and I've been going all over the show on it since I put it on.

 

[vfr400]

I already told you, you can't use voltage to caculate range because there's a non-linear relationship between them. Instead, get a wattmeter from Ebay. They cost less than a tenner, and they give a good measurement of battery capacity, range and consumption. If you can install one where you can see it on the handlebars, you'll learn a lot about how your bike works.

 

[Manc44]

I already told you, you can't use voltage to caculate range because there's a non-linear relationship between them. Instead, get a wattmeter from Ebay. They cost less than a tenner, and they give a good measurement of battery capacity, range and consumption. If you can install one where you can see it on the handlebars, you'll learn a lot about how your bike works.

Cheers vfr400 yes I remember you mentioning this before. I'm useless at soldering etc. As long as I know it's getting near the end at around 45V (or 40% battery left) I'll be OK leaving it as it is. It makes me laugh how fast it goes on a fresh charge. It would be good if the controller had a thing in like they put in eCigs so, no matter what voltage is left, it always supplies the same power, in other words it's not stronger on a fresh battery and it doesn't "fade" near the end. I think my eCig cuts out when the cell gets to 3.1V. If that same tech was in a controller it wouldn't go faster on a fresh charge which is how I'd prefer it, you'd also get more range that way.

Is it true, on more expensive systems like the Bosch, the battery range takes all that stuff into account, thus giving a more accurate reading on percentage left?

 

[vfr400]

Is it true, on more expensive systems like the Bosch, the battery range takes all that stuff into account, thus giving a more accurate reading on percentage left?

It has a bit more intelligence, but it can never know where you're going to ride, when one hill can take 20% from the battery.

 

[Manc44]

It has a bit more intelligence, but it can never know where you're going to ride, when one hill can take 20% from the battery.

Pah! You'd think they'd have a chip in that learns from your riding or something. Even after using one battery cycle it could get to work adjusting it all.