Is it the battery or the power display instrument

Phil

New Member
Hi. Hope everybody is doing good and riding lots. We have a EbikeBC 350w, it's about a year old and is running great. A week ago my wife said when she started her ride to the store, she seen the power display instrument on the handlebars showed only 3 lights were on. Then when she was coming home there were 4. this is happening all the time now. The battery is charged after every ride. Can someone tell me if it's the battery or the display instrument. The battery takes about the same time to charge as it has always took.
 

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ebikemom

Administrator
Staff member
It could also be the controller. The display connects to the controller.

I suggest you contact the bike's manufacturer to get your question answered. :)

In my experience with my own bike, though, the "bars" that show voltage level on the display almost always move in a decreasing direction. but there are exceptions--for example, yesterday on the way home from work the display was showing three bars (out of five), then four, , then back to three, ....... then briefly two, then back to three. These weren't rapid changes. This is normal for my bike that has 2500 miles on it--it's always been like this, though this kind of variation isn't frequent so I don't notice it on every ride.
 

harryS

Well-Known Member
It sounds like a short trip and you're always used to seeing 4 lights coming home.

Is it colder where you ride now? The battery is a chemical process that is temperature dependent. When cold in the morning, voltage will read a little lower and it will self heat a little as you ride. An older battery might not charge as high and leave you right on the cusp of 3/4 lights. A little riding and there's enough self heating to ring the level back up, provided you haven't ridden so far that the charge goes back below 3 lights,

Then again, it could be the display. Battery displays that show bars/led's are imprecise.

If you know how to use a voltmeter, check the battery after a charge and then recheck it in the morning.
 

JRA

Well-Known Member
The bar meters common on eBikes are just basically voltmeters. So a battery at full charge will show full bars but as voltage drops through use that is when they will start to disappear. However when a burst of power is applied voltage will sag and at times, depending on what state the voltage is at in relation to the meters parameters, a light will go off but when you let off it will reappear.

I see a lot of chatter on this and other boards about how someone went x distance and had y bars left on their meters and from there making the assumption that they had z distance remaining.

But you have to take into account the fact that as voltage drops so does motor efficiency and you can’t count on each bar to yield the same amount of mileage. Especially the lower ones.
 

Phil

New Member
Thank you for your input everybody. I do think I will try to contact the manufacturer. I never thought about it being the controller. I guess I was hoping everyone would say, it's that cheap little display instrument. So if and when I get it fixed I will let you know what I had to do. Thanks again for your replys
 

harryS

Well-Known Member
Hi Phil, it's not going to be the controller, in my opinion. Those little LED units are pretty simple and it's cheap to put the voltage measurement in the display. Your unit could be different, but I have tried several of my display units connected directly to my battery and they don't need the controller to power up and display voltage.

So that leaves your display and maybe the battery as culprits. As long as the display isn't grossly wrong, and is telling the truth when you're down to one or two bars, maybe you can live with it.
 

Trail Cruiser

Well-Known Member
Hi. Hope everybody is doing good and riding lots. We have a EbikeBC 350w, it's about a year old and is running great. A week ago my wife said when she started her ride to the store, she seen the power display instrument on the handlebars showed only 3 lights were on. Then when she was coming home there were 4. this is happening all the time now. The battery is charged after every ride. Can someone tell me if it's the battery or the display instrument. The battery takes about the same time to charge as it has always took.
Battery capacity slowly degrades over time. As long as you have reasonable range per charge, you should be fine. Also, cold weather decreases the battery performance and range.
 

Phil

New Member
Hi everybody. Thanks for all your help. I emailed the manufacturer, they said it was more then likely the display instrument and they would give me a good deal on a better one. But before I could save up the money, it fixed it self, it just started to work again like it always did. So far it's still good, but with -14 to -20 weather outside right now we are not riding anywhere. So Bulkley Bob I hope you have the same luck we did. Thanks to all for your help. Phil