Am I imagining it?

[Jimod]

OK, here's the story: I've got a Kudos Tourer which I love to bits and get between 30 and 40 miles from the battery, depending on route taken and how lazy I am. My wife bought me a spare battery and I charged it up and decided to fully discharge it to condition it. When I started using the new battery I thought I imagined the bike was more powerfull but just put it down to wishfull thinking. Today, however, I was out when the new battery went flat and had my original battery with me (aren't I clever) So I changed them over. Now I'm sure the new battery pulls up hills better than the original battery ever did. They are identical batteries, so is it in my head? I was also sure the motor was quieter uphill with the new battery but I'm certain THAT is in my head.

Hopefully on Friday I'll get the chance to take them both out and use them on a long trip. Then I'll prove to mysellf that I'm right....or wrong.

I have no complaints about the original battery, I'm just more impressed with the new one.

 

[flecc]

Excellent clues there indicating it probably is imagination Jim.

A better performing battery giving more performance on these hub motors produces more motor noise. But as yoiu see, you've perceived the opposite, the new battery giving more power but less noise.

Therefore, balancing out those two factors probably means the batteries are roughly the same.

A better comparison is to fully charge both, then do a return mile on one, followed by the same return mile on the other so that they are being compared at a similar time in the same charge state in identical conditions.

 

[Deleted member 4366]

I suspect that the new battery is working at a slightly higher voltage for whatever reason - only a meter would show it. It's probable that the new battery has less internal resistance so gets less voltage sag under load.

I've also discovered that a more powerful battery causes the motor to make less noise. The reason is simple: that the higher voltage causes the motor to run faster (as it has more power) and so it runs under less load.

So, in my opinion, it's not your imagination. I'm sure your new battery is indeed better than your other one. It would be interesting to look inside it to see what cells are in them. My mate Steve did the same as you and bought a second battery from his bike supplier. when we opened them up, one had large cylindrical cells and the other had flat pouch cells, so they were totally different inside, but looked the same on the outside.

 

[Jimod]

OK two replies and two different answers.
I will be trying Flecc's advice and do the same mile with both batteries right after each other. The trip this morning though was 10 miles and I've done that with each battery and in my mind the new battery is better. Those trips were done a couple of days apart and the wind was stronger against me when I used the newer battery.

Luckily I live at the top of a hill so plenty of opportunities to do a short quick battery test.

The batteries may be different inside, I won't be opening them, the older battery isn't old it was bought with the bike in July. The new battery was bought a few weeks ago.

I've been back out and I think I know why the new battery makes the motor quieter. The speed up hills IS faster and I've always known that if I am under 11.5 mph up a hill the motor makes more noise.


OK Now to get both charged and I'm not working on Friday, I'll see how I get on.

I'll probably be reporting that I've been dreaming.

 

[flecc]

I've been back out and I think I know why the new battery makes the motor quieter. The speed up hills IS faster and I've always known that if I am under 11.5 mph up a hill the motor makes more noise.

Thanks for the feedback Jim, our answers don't disagree as much as they might at first appear.

At any given speed under load, more power applied to the load produces more noise, but since the noise reduces with speed as d8veh says, any higher speed gained that you observe at produces less noise.

I suppose ideally you'd need to do the exact copy runs twice over, first with the "old" battery used first, second with the "new" battery used first, these to eliminate any variations in your input. But that's being super fussy, once will do for me.