Electric bicycle build (introducing "black & red")

[California98Civic]

Originally Posted by NeilBlanchard

Do you think if you do 4-cross spokes, that would address the broken spoke issue?

I took this question with me to my bike shop, where the wheel was repaired today. The owner/mechanic there does not think it would help much. He called it an old BMX technique. He can be a little dismissive though. A little bull-headed.

He said people have done tests, showing it stronger, I guess. But he insisted the extra cost is not worth it. Hmmmm...

He was also wicked dismissive of my eBike build three years ago. Everything I did was wrong in his eyes. Now he sells eBkies, too. Lol

[Grant-53]

A three cross pattern with heavier gauge spokes should work. Check out the the rear spokes on a light dirt bike.

[California98Civic]

I crossed 5000 miles on the eBike yesterday. Same battery. Even the same tire on the powered wheel. That's 5000 miles not driving.

[Grant-53]

Clearly you have the bike working well. So consider the aero package. I know there is always one more project or detail cropping up.

[jjackstone]

Nice. I pretty much quit riding mine about ten years ago after 4000 miles. I will take it out once in a while just to make sure it still works. The grip shifters are shot and the rear derailler is falling apart, but the motor still runs just fine. I still use the batteries in my Dewalt 36 volt drill though. So those LifePo4 packs are now 12 years old and still relatively strong. One day I'll have to see how much charge they still hold.
JJ

[California98Civic]

Originally Posted by jjackstone

Nice. I pretty much quit riding mine about ten years ago after 4000 miles. I will take it out once in a while just to make sure it still works. The grip shifters are shot and the rear derailler is falling apart, but the motor still runs just fine. I still use the batteries in my Dewalt 36 volt drill though. So those LifePo4 packs are now 12 years old and still relatively strong. One day I'll have to see how much charge they still hold.
JJ

It would be really interesting to see how the batteries are doing. Mine were being incorrectly charged it would seem. I had ordered 12s battery for my 43.5 volt charge, IIRC, and was apparently sent a 10s battery. This meant I was charging it for 4000 miles of riding without a balancing cycle. When my original 43.5 1amp charger was doing the charging I think the slowness did little or no damage because I was not discharging battery more than 1/3 or 1/2. But when that charger broke, I looked long and hard for a good quality 43.5 volt replacement. Got a 4amp one. Soon, I started seeing "fully charged" responses from the charger when the battery showed a little lower than normal. Then I started seeing radically lower "fully charged" voltages. And then even those voltages would not sustain themselves and I would find really significant voltage drop over night or a few days without a load on the battery.

I figured out that the battery was 10s and not the 12s I had ordered. I got a 42 volt 2amp charger and everything returned to normal for the last two or three hundred miles.

These batteries are durable!

[California98Civic]

I think the battery I had is toast. Been almost 2 years procrastinating the repair. But I want to revive the bike with a new inexpensive battery, maybe off eBay. Advice on how to confirm whether my old 14 ahr, battery really is a 10s or a 12s 36volt battery?

[jjackstone]

Is it a major problem to open it up and count the cells? I forget what chemistry you had. LiFePo4 at 43.5 volts would indicate 12s as that chemistry charges to 3.6volts/cell and operates nominally at 3.2 volts/cell. Lithium ion will normally charge to 4.1 or 4.2 volts/cell and operate at 3.7 volts/cell. So if they are lithium ion I would think 10s would be logical.
JJ

[California98Civic]

Originally Posted by jjackstone

Is it a major problem to open it up and count the cells? I forget what chemistry you had. LiFePo4 at 43.5 volts would indicate 12s as that chemistry charges to 3.6volts/cell and operates nominally at 3.2 volts/cell. Lithium ion will normally charge to 4.1 or 4.2 volts/cell and operate at 3.7 volts/cell. So if they are lithium ion I would think 10s would be logical.
JJ

It is supposed to be LiFePO4 and 12s. I guess I will have to open it up and count. I have been hesitant because of unfamiliarity. On a related point, can I mix chargers with batteries, or does LiFePO4 or Lithium ion each require a specific charger?

[jjackstone]

I think as long as you are talking about a pack voltage as opposed to individual cells, that the same charger should work for either pack. The two chemistrys have similar charging parameters. They start with a constant current charge and then at some predetermined point of charge level the charger switches over to a constant voltage level and limits the current until the charger determines the pack is full. Of course this assumes that the pack voltages are the same. I would ask the manufacturer or the dealer you purchase the pack from if the same charger can be used.
JJ