Battery Charging Recommendations

[mtblair]

I know there are other threads here about batteries, but the members here are often "tinkering" and seem to have a better understanding of them than other resources.

I have a Rad Mini ST2. Right now I do daily short rides to work and back and local errands on the bike. It may take two or three days of riding for the battery level bars on the LCD display to go down one bar, although I know that it's being drained each time I ride.

My question is: Should I put the battery on the charger after each ride regardless of the display status or should I wait until it's down to one or two bars to charge it?

It seems like the battery, next to tires, is the most expensive replacement item so it makes sense to get the most out of it.

Thanks in advance.

[FletcherD]

I'm not as knowledgeable as a lot of people in this forum and I'd be more than happy if they correct anything I say. I've done a lot of research about extending battery life, because it's the most expensive component on the bike. According to Rad, it's totally fine to fully charge your battery after every use, however that's mainly so you have a fully charged battery every time you want to hop on your bike. My understanding is that this does nothing to damage your battery. However, what you're  doing is probably better. If you're taking it for short rides and have a certain percentage left, you can keep riding until it's at the lower range and needs to be charged back up. It's definitely not good to have the life sucked out of it, because it can actually, well, die. But if you're keeping an eye on it and topping it up before it gets to the point of no return, it could extend the life of your battery. Each time you charge the battery, it's making your battery work and in a sense, using up energy which over time adds up and shortens the overall life. In conclusion, charging every day does not damage your battery, but charging more when it really needs the boost is gentler on the battery and helps to lengthen its life.

[Eric7]

Total discharge or big discharges (including discharge to 20% for example) of the Li battery is hard and damaging to the battery.  They should not be overcharged or deeply discharged.  So I would start charging the battery when it is about 50% for basic long life.

My other view, not shared by anyone, is that you just want to enjoy the bike - even Rad tells you to do that. Worrying about the battery is not worth the anxiety.  Your first battery should last a long time.  Just buy another battery when the current one's range is reduced. Then you will have two batteries.

Slightly different subject.  My Prius' battery is still good after 13 years.  The car's program limits the range of charging to between 60% to 80% at all times.  I know some Tesla owners with great success with some schedule like that too.  My feeling is that it would make for a miserable bicycle owner.

[mtblair]

I take the battery off and store it in the house after each ride. It's a 30 second step to put it on the charger. I like the idea of charging once it gets down to 50%.

I'm also a believer in the "ride, not worry" philosophy. Hopefully, in a couple of years, someone will come up with replacement batteries with a longer range and that aren't a 7-pound brick.

[Eric7]

https://www.radowners.com/index.php?topic=1860.0   This link is for a detailed discussion.

My personal advice on how to read the battery meter to help you monitor battery percentages. The battery meter has 5 bars.  Ignore the lowest bar.  Pretend it does not exist.  Then the meter is more linear and more representative of the true state. 

Here is my alternative suggestion which is not totally accurate but a lot more accurate than what the manufacturer wants you to believe.  Presenting the "Eric7 Scale". 

***** = 100%
****  = 75%
***  = 50%
** = 25%
* = 12%

[Ddaybc]

I recharge my battery once it has lost two bars unless I have a long ride the next day. Then I fully charge it.
Maybe it's just me but I usually ride short rides when I ride so there's no need to fully recharge it each time. From what I understand it is better for the battery but I do it because I'm using the least amount of effort to keep it going well. Basically lazy 

[DickB]

Two bars is as low as 15% SOC (State Of Charge) and not recommended on a regular basis. (My chart is based on extensive real-world testing of my Rover 5. I characterized the battery meters on the battery and display with a variable power supply to get precise readings.)

If you're not altering anything, best advice for longevity is to charge after every use. Despite what Rad says, leaving the charger on for more than 12 hours causes no harm. Extended time on the charger after the green light comes on enables cell balancing and is beneficial to the battery.

For maximum battery longevity, keep the SOC between 80% and 40%. There are aftermarket chargers that allow you to select 90% or 80% SOC. I use a homemade diode device plugged in between the Rad charger and battery to reduce the final float voltage to achieve about 80% SOC and charge after every ride. I ran a capacity test when the battery was new. I have 2700 miles on the battery after 9 months use and will run another capacity test at 12 months to check longevity.