Rad Power Bikes Owners Forum

Discussions by Rad Model => RadRunner => Topic started by: HondaZ50M on March 03, 2023, 01:55:29 AM

Title: Radrunner top speed gradually lowers with battery drain
Post by: HondaZ50M on March 03, 2023, 01:55:29 AM
Top speed gradully decreases with battery drain.

Fully charged it'll do 20mph, at 80% 18mph, 60% 16mph, 40% 15mph

Is this normal?

I could understand if battery was getting low.
Title: Re: Radrunner top speed gradually lowers with battery drain
Post by: santacruzpaul on March 03, 2023, 08:43:25 AM
Seems to me to be normal for e-bikes, There are video's on YouTube on this subject.
Title: Re: Radrunner top speed gradually lowers with battery drain
Post by: handlebar on March 03, 2023, 01:39:53 PM
Quote from: HondaZ50M on March 03, 2023, 01:55:29 AM
Top speed gradully decreases with battery drain.

Fully charged it'll do 20mph, at 80% 18mph, 60% 16mph, 40% 15mph

Is this normal?

I could understand if battery was getting low.

An electric motor is like a generator that produces "back EMF" - voltage against the applied voltage. The faster it turns, the more back EMF it produces.

The battery puts out less voltage as it discharges, so it won't turn the motor as fast. When fully charged, mine is also peppier at slow speeds.
Title: Re: Radrunner top speed gradually lowers with battery drain
Post by: joeliniowa on March 04, 2023, 06:57:55 PM
That's right, the "ride out" is faster than the "ride back" plus or minus points for wind.