BIKE DIARY JUNE 30/22

I note, in passing, that I put on about 720 km in the last month.

Start time 9:45 pm 

Temp 19.1 C

Start Voltage                                 57.5

Finish Voltage                               ?

Ah                                                 31.82

Trip Distance                                77.92 km

Distance                                      11,581 km                                

Time                                            142:43

Av. Speed                                     32.7

Trip Wh/km                                   20.9

Trip Wh                                      1624.30

REVISED BATTERY LISTING (WORST TO BEST)

Battery          Usable W/h       Available A/h        % loss (W/h)                       

#10                    691.24                 14.54                   14                

#8                      709.10                 15.10                   11                

#3                      726.98                 15.36                     9 

#6                      730.50                 15.65                     9

#1                      733.70                 15.82                     8             

#4                      745.50                 15.41                     7                

#2                      741.30                 15.66                     7              

#9                      743.25                 15.69                     7                

#5                      756.60                 15.91                     5   

BATTERY TEST ON BATTERY #6 (REPEAT)

1st Test                                         2nd Test

Watt hours = 570.78                     730.50

Amp hours =   12.31                       15.65

% Loss      =     29                              9

Odometer =  11,201 km                11,502 km

Very good test tonight! It's also good because it validates my theory about what the problem was. Further, I feel this battery will be a reliable source of power when used in tandem with one or two other batteries. I would be leery about using it alone, though.

Total trip distance today: 58 km. 

DEALING WITH BATTERY #6

 I have written about the poor performance of battery #6.

Watt hours = 570.78

Amp hours = 12.31

"Today's test was very disappointing. Number 6 battery has lost 28% of its original power. I knew something was not right when the battery only registered 56 volts at full charge instead of the normal 58.4 volts. This was completely unexpected. 

Should one cell in the battery behave badly (discharges too quickly) it will suffer premature voltage sag and trigger the BMS to shut down the entire battery. 

A further effect is that a cell that discharges too quickly will also charge too quickly. The defective cell reaches its peak voltage before the rest of the other cells resulting in them being undercharged."

Today I took Battery #6 and trickle charged it. I did this by charging it in tandem with two other batteries using a three headed charging device. This had the effect of reducing the charger's 4 amp capacity to 1.33 amps.

Well the charging is complete and the result is that the battery now shows 58.0 volts!

It is now 9:20 pm PDT and, in an hour, I'm going to go out on a depletion run.  I will post the results when I get home which will be about midnight. 

I would go out right now but there are hordes of flying insects out at sunset and they get in my eyes and nostrils. 

RANKING BATTERIES #1 - #10

Batteries are listed from worst to best according to their percentage of loss of maximum potential charge.

You can see that the number of W/h per A/h varies. They vary depending on how hard you push the battery. The faster the battery discharges the more internal resistance there is in the battery causing it to heat up. The energy used to create heat is energy not used for conversion to watts resulting fewer km travelled per W/h.

Want maximum range out of a battery? Slow down.

Baseline original charge = 800 Wh and 16 Ah.

Battery          Usable W/h       Available A/h        % loss (W/h)       

#6*                    570.78                 12.31                    29                  

#10                    691.24                 14.54                   14                  

#8                      709.10                 15.10                   11                      

#3                      726.98                 15.36                     9 

#1                      733.70                 15.82                     8                       

#4                      745.50                 15.41                     7    

#7                      744.33                 15.50                     7            

#2                      741.30                 15.66                     7              #9                      743.25                 15.69                     7          #5                      756.60                 15.91                     5                    

There is an asterisk beside #6 battery because the low charge is a result of low voltage due to an internal malfunction - probably a bad cell.

BATTERY TEST ON BATTERY #1

Watt hours = 733.7

Amp hours = 15.82

Odometer = 11,445 km.

Very good test tonight! Number 1 battery only lost slightly over 8% of its original power.

The bike got 35.2 km range out of 734 W/h at an average speed of 33.0 km/h using 20.9 Wh/km.

Total trip distance today: 53.98 km. 

And remember: batteries #1, #2, and #3 are 5 years old!! These are pretty damn good results!

BATTERY TEST ON BATTERY #2

 Watt hours = 741.3

Amp hours = 15.66

Odometer = 11,391 km.

Excellent test tonight! Number 2 battery only lost slightly over 7% of its original power.

The bike got 37.2 km range out of 741 W/h at an average speed of 32.0 km/h using 20.2 Wh/km.

Total trip distance today: 50.84 km. 

And remember: batteries #1, #2, and #3 are 5 years old!! These are pretty damn good results!

BATTERY TEST ON BATTERY #3

Watt hours = 726.98

Amp hours = 15.36

Odometer = 11,340 km.

Another good test tonight! Number 3 battery only lost slightly over 9% of its original power.

The bike got 36.5 km range out of 727 W/h at an average speed of 32.0 km/h using 20.2 Wh/km.

Total trip distance today: 46.97 km. 

I WANT TO SEE 12,800 KM ON MY ODOMETER TOO! (JUST SAYIN')

Jack Butler's solar powered electric bicycle traveled 12,800 km in 64 days from France to China

BATTERY TEST ON BATTERY #4

Watt hours = 745.5

Amp hours = 15.41

Odometer = 11,294 km.

Another very good test tonight! Number 4 battery only lost slightly under 7% of its original power.

The bike got 38 km range out of 745 W/h at an average speed of 31.2 km/h using 19.5 Wh/km.

Total trip distance today: 39.75 km. 

BATTERY TEST ON BATTERY #5

 Watt hours = 756.6

Amp hours = 15.91

Odometer = 11,254 km.

Great test tonight! Number 5 battery performed almost as new. It only lost slightly over 5% of its original power.

The bike got 39 km range out of 756 W/h at an average speed of 31.3 km/h using 19.5 Wh/km.

Total trip distance today: 43 km. 

As an aside, the best compromise between speed and efficiency would appear to be 30 km/h. 

FURTHER COMMENT ON BATTERY #6

Not my battery. It just shows what the inside of a battery looks like.

The Hailong  52 volt x 17.5 Ah (nominal) is composed of 70 cells. They are configured into 14 groups (connected in series) of 5 cells (connected in parallel) - written as 14s5p. 

Should one cell behave badly i.e. discharges too quickly, it will suffer premature voltage sag and trigger the BMS to shut down the entire battery. 

The net effect of this is that the rest of the cells still hold some charge but you cannot access it. 

A further effect is that a cell that discharges too quickly will also charge too quickly. The defective cell reaches its peak voltage before the rest of the other cells resulting in them being undercharged. 

The bottom line is poor battery performance showed by last night's test. There is a cure but tearing the battery apart to find the deviant cell is too time consuming and, therefore, too costly.

BATTERY TEST ON BATTERY #6

Watt hours = 570.78

Amp hours = 12.31

Odometer = 11,201 km.

Today's test was very disappointing. Number 6 battery has lost 28% of its original power. I knew something was not right when the battery only registered 56 volts at full charge instead of the normal 58.4 volts. This was completely unexpected. When batteries start to weaken it usually shows up in less Ah - not a decrease in volts.

The bike only got 30 km range out of 571 W/h at an average speed of 30.4 km/h using 19 Wh/km.

Total trip distance today: 45 km. 

BATTERY TEST ON BATTERY #7

Watt hours = 744.33

Amp hours = 15.50

Odometer = 11,165 km.

Second test today. Another excellent test. Battery has only lost 7% of its original power. The bike got a 40 km range out of 743 W/h at an average speed of 29.3 km/h. Very good.

Total trip distance today: 81 km. Total outing distances differ from battery depletion distances because I have to get back home when the battery depletes. I always carry a second battery to do this.

BATTERY TEST ON BATTERY #8

click on image to enlarge

Watt hours = 709.1

Amp hours = 15.10

Odometer = 11,124 km.

Test shows #8 is my 2nd weakest battery. Battery has lost 11% of its original power. The bike got a 35 km range out of 709 W/h at an average speed of 33.7 km/h. The range is still acceptable.

BATTERY TEST ON BATTERY #9

to enlarge click on any picture

Woodmont: French Gothic style mansion sits on 72 acres. Located in Gladwyne, Pennsylvania. Built in 1894 at a cost of $1 million. That would be about $32 million in current dollars.

One of my favorite homes.

Watt hours = 743.25

Amp hours = 15.69

Odometer = 11,085 km.

Excellent test tonight. Battery has only lost 7% of its original power. The bike got a 38 km range out of 743 W/h at an average speed of 30.5 km/h. I consider this very good.

A FIRST!!!

I woke up this morning and noticed my first flat tire!! The front tire had a hole worn through the tread. 11,000 kms. The front tire is only a 20" tire so it probably had the equivalent of 15,000 kms compared to the rear tire. This is good mileage. 

I have a spare set of Schwalbe Marathon Plus tires so I am getting my bike guy to install them and transfer the kevlar liners.

BATTERY TEST ON BATTERY #10 (UPDATE: TEST #2)

Another great day. Overcast but comfortable  Temp 19 C.

Watt hours = 677.13

Amp hours = 14.38

Odometer = 11,006 km.

Very disappointed in today's test. #10 battery is supposed to be one of my better batteries. I expected about 720 W/h. The Ah are also low. I will update this post when I recharge the battery. Perhaps it wasn't fully charged. 

NOTE: I just unwrapped the battery. When I test a single battery I put it in my rear basket and I wrap the battery in a beach towel in order to cushion it from road shock. When I unwrapped the battery it was hot to the touch. Perhaps the battery overheated and the BMS shut it down early. I'll keep you updated when I do a second test without the wrap.

Test #2

Watt hours = 691.24

Amp hours = 14.54

Odometer = 11,046

While I kept the battery uncovered there was not much improvement in its performance. Still disappointing.

77 km today. 2.5 hours saddle time. Not at all tired.

BATTERY TEST ON BATTERY #11

Another great day. Lots of sunshine. Temp about 19 C.

Watt hours = 646.66

Amp hours = 13.76

Odometer = 10,969 km.

As you can see, the W/h and Ah are very nearly identical to the previous four tests.

Summary of #11 through to #15

#11 = 646.66 W/h    13.76 Ah

#12 = 640.82 W/h    13.86 Ah

#13 = 639.60 W/h    13.74 Ah

#14 = 641.40 W/h    13.13 Ah

#15 = 642.70 W/h    13.27 Ah

BATTERY TEST ON BATTERY #12

Great day. Lots of sunshine. Temp about 19 C.

Watt hours = 640.82

Amp hours = 13.82

Odometer = 10,930 km.

As you can see, the W/h and Ah are very nearly identical to the previous three tests.

BATTERY TEST ON BATTERY #13 (MY PSYCHO BATTERY)

Watt hours = 639.6

Amp hours = 13.74

Odometer = 10,900 km.

Battery #13 is my worst battery - at least it was. It has (had?) a bad cell which had premature voltage sag (and none of us wants premature voltage sag). This caused the BMS to shut down the battery and caused the bike to stall on acceleration from a standing start. Today, there was no problem. Why is this?

I can't answer this definitively but I will tell you this: even when batteries are not in use there is electrical activity going on. I have not used #13 for a year now. I have kept in indoors and kept its storage charge at a steady 85%. Somehow, during this extended interval of non-use its molecules have rearranged themselves so as to "cure" the premature voltage sag. Pure speculation on my part, though.

HOPING FOR SOME DECENT WEATHER

It's 5:01 am here in Richmond , BC. The sky is quite overcast and it is cool: 13 C. The last couple of days have been rainy and cool. I'm chomping at the bit to do some more testing. We'll see.

BATTERY TEST ON BATTERY # 14

Watt hours = 641.40

Ah hours = 13.13

I repeat: These figures are very good considering the battery's about 18 months old. When it was new I tested it and got about 660 Wh. So the loss is only 2% or 3%.

That said, this battery (and the four others purchased at the same time: batteries #s 11 through 15) have a lot more voltage sag than batteries #s 1 through 10.

So, when the battery has used up about 40% of its energy the voltage sag is sufficient to cause the bike to stall out when accelerating from a standing start. To avoid stalling one must accelerate from a standing start very gingerly.

Odometer reading 10871 km.