Battery range

[wehey]

Hiya all.
I went out for my first proper ride today on my converted bike and I was wondering if my battery usage is normal.
I have an Ezee conversion kit (unrestricted) and a 48v 10.4ah battery (battery from eBay). Battery was fully charged.
I planned a route of 12 miles and as I live a stones throw from the South Downs I decided to go up and over (by road) then back along the foot of downs.
The top of the hill is about 3 miles from home and it's about 1.5 miles from bottom to the top. I used assistance level 3 and put in about 50% of my normal effort.
By the time I reached the top I had used 50% of the battery. Would I be right in saying that steep hills really eat into the battery?
Once I reached the top I was worried that I wouldn't have enough battery left to get me home so I switched to assist level 2 and rode the rest of the way home using 75% leg power on the flats and assist up any small hills i came across.
By the time I was near home I had 1 orange bar left on the battery. I then did about 1.5 miles on full power to empty the battery onto red.
All in all I did about 13.5-14 miles until the battery was on red.
Does this sound about right considering the hills I climbed?

 

[trex]

steep hills consume a lot more battery - but the range of a 48V 10AH is about 30-35 miles on flat roads. Every 100m elevation will use about 40WH-45WH, so if you ride 7 miles and climbs 100 m on the way out then same on the way back, that works out about 140WH for flat roads on account of you pedalling hard, 90WH for elevation, total 230WH
I expect you use 45% of your battery.
You should have 2 bars out of 4 on the battery meter. One bar is a bit low.

 

[wehey]

steep hills consume a lot more battery - but the range of a 48V 10AH is about 30-35 miles on flat roads. Every 100m elevation will use about 40WH-45WH, so if you ride 7 miles and climbs 100 m on the way out then same on the way back, that works out about 140WH for flat roads on account of you pedalling hard, 90WH for elevation, total 230WH
I expect you use 45% of your battery.
You should have 2 bars out of 4 on the battery meter. One bar is a bit low.

Thanks, that's really interesting. When you say it should do 30-35miles on the flat, is that flat out or at what sort of assistance level.
I just looked up the elevation and I climbed 133metres over about 2 miles

 

[trex]

flat roads mean 15mph, with easy pedalling. ebike.ca web site gives a figure of 160W assistance power, that is to say you would use 160WH to travel 15 miles on flat roads. For elevation, you need to check both ways then add the two figures together then multiply by 0.45 to get the consumption in WH.

 

[wehey]

The thing is that the battery is brand new. I think I need to do a 15mph flat road test. I recon that would be assist level 3 on this set up and also a good excuse to go for a long ride

 

[jackhandy]

You need a few rides under your belt before the battery's run in & giving its full capability.

My Ezee 14ah 36v batteries, both of 'em, are still half-full just about when they drop from 2 to 1 amber.

1 red Does Not Indicate Empty & lasts, normally, many miles before cutting power. Cyclezee recommend 1 red as the point you should recharge.

Once they've sagged on a long slog up, they take a while to recover, but the led state doesn't corespond to the voltage shown by a Speedict:
Sometimes they can be down to 1 amber & still giving 40v.

This is according to my 36v batteries, of course.

 

[wehey]

You need a few rides under your belt before the battery's run in & giving its full capability.

My Ezee 14ah 36v batteries, both of 'em, are still half-full just about when they drop from 2 to 1 amber.

1 red Does Not Indicate Empty & lasts, normally, many miles before cutting power. Cyclezee recommend 1 red as the point you should recharge.

Once they've sagged on a long slog up, they take a while to recover, but the led state doesn't corespond to the voltage shown by a Speedict:
Sometimes they can be down to 1 amber & still giving 40v.

This is according to my 36v batteries, of course.

Interesting stuff guys, especially as this all new to me.
I must admit I noticed the same as you mention. Once I had 1 amber left it took a hell of a blast at full power to get to a red light. My battery isn't an Ezee tho.

Also noticed that once it dropped to 2 ambers after the climb it jumped back to 1 green after a long downhill.

Is it safe for the battery to keep running on red as I have read that you should charge it when it's 90% empty to prolong its life.

 

[jackhandy]

Is it safe for the battery to keep running on red as I have read that you should charge it when it's 90% empty to prolong its life.

Opinions vary

Cyclezee's recommendation for their batteries is to recharge when showing 1 red.
Going down to lvc cutoff should only be very occasional .

A "battery from ebay"... depends entirely what it actually is - many turn out to be optimistically specified. Others are excellent.

Just out of interest, how did you manage to get an Ezee kit sans battery?

 

[Geebee]

The big thing to take into account is if this was the first charge disregard the range info, mine double its range on the second charge and Lithium usually takes up to 3- 5 charges to settle into max life.

 

[Deleted member 4366]

The higher voltage also increases consumption a bit because the efficiency band gets pushed higher up the rpm range. During hill-climbing a 48v motor will be more powerful but less efficient than the same motor at 36v, so you wadte more battery power. Your mileage sounds about right to me.

48v is better for speed and power, but 36v is more efficient in its usr of battery.

 

[wehey]

The big thing to take into account is if this was the first charge disregard the range info, mine double its range on the second charge and Lithium usually takes up to 3- 5 charges to settle into max life.

Yep it was.
I charged it out of the box, rode it, charged and rode it. So I'm currently charging for the 3rd time ready for this afternoon (after I have laid my shed base )

 

[wehey]

So how can you actually tell how much charge you have remaining in your battery? Could you use a multimeter? What settings would you use?

I just went for a full power blast along the seafront to see what occurring with the battery.
I did 6miles flat out and it went onto red. I can't help but think that there is still a ton of charge remaining as I continued flat out for another 4 miles and it was still performing as if it had it was just charged with no deterioration in performance at all.

 

[wehey]

The higher voltage also increases consumption a bit because the efficiency band gets pushed higher up the rpm range. During hill-climbing a 48v motor will be more powerful but less efficient than the same motor at 36v, so you wadte more battery power. Your mileage sounds about right to me.

48v is better for speed and power, but 36v is more efficient in its usr of battery.

I get what your saying here. I did a comparison on https://www.ebikes.ca/tools/simulator.html swapping a 40v10 for a 36v14 to see the difference.
The 36 has much more range esp at the higher assistance levels.

 

[Deleted member 4366]

You need a wattmeter to know know how much battery you used or have left. The cheapest one is about £6.50. See my "best value wattmeter" thread for what to do with it.