profstack

In an email from Bionx, it was suggested that I totally run the 555Wh battery down and do a full recharge once in a while. That I did. BTW, I got the battery in June.

When there are none of the 8 bars showing, the battery still puts out energy, albeit less as the storage wanes. The battery emits a chirping sound when things get close to empty. After three such sounds I headed back home and put the charger and Ensupra meter on the battery. The meter measures, among other things, the Wh used in charging. The battery was not entirely drained, but pretty darn close as far as I could tell.

Anyway, the green light came on when the meter showed 592Wh, not the 555Wh spec, so I guess that is a good thing. One thing doing a full charge is supposed to do is better calibrate the 8 bars for when they come off during rides. We'll see how that works out.

The Bionx email also said that charging the battery after each ride is fine. Some people say that keeping the battery between 20 and 80% is also a good thing for some batteries.

So, this post is a public service announcement that sometimes things are better than advertised.

Ridefreemc

I'll look forward to getting that email, as the advice they give is usually "don't" drain it empty.

profstack

Oh, the email came from a query I made earlier, trying to clarify the best charging strategy to prolong the life of the battery.

Ridefreemc

Thanks, I'll check in with them.

chas58

#1 what you stated above can double or tripple battery life. Not charging to 100% isn't critical, but it can make a big difference.
#2 would be to charge it after every ride, and not let it get too low as that hurts life too (below 20%).
#3 is important - don't let the thing totally discharge in the winter (i.e. times of prolonged storage). Charge it every 3 months minimum. If a cell voltage gets too low, you may never get it back.

2old

It's been reported that Tesla is able to provide an eight year warranty on their batteries because they neither let them charge above 80% nor discharge below 20%.

profstack

Is the type of battery in the Bionx the same as that of the Tesla? i.e., is the 20-80 charging strategy effective for the Bionx and Tesla? With the range of the 590Wh battery, keeping it between those levels is not that difficult to maintain.

350htrr

If you put 592watts into a 555wh battery I would suspect it's charged to 100%, and taken down to close to 0%... JMO

2old

Prof, I THINK the 80/20 rule applies to most if not all Lithium batteries. It's been reported that Tesla uses 18650 Panasonic (they own 10% of Tesla) and/or Samsung Lithium batteries, so very similar or the same as some ebike batteries. The "older" chemistry (still used by some) was LiFePO4 and I'm pretty sure the 80/20 rule applies there too. Some vendors (em3ev for one) will set the charger to only 80%; the problem is that sometimes you need to keep the battery at full charge for some time (days maybe) to balance the cells. Too complicated for me; I just keep my battery charged; it's LiFePO4 which should last three years anyway. Go to battery university or endless sphere if you want to unlearn what I just said, and learn the truth.

chas58

Do you want 500 charges or 1500 charges from your battery?

The Chevy Volt keeps the charge mostly in the 30-80% range as I recall and has the 8 year/100000 mile warranty. Effectively it only uses a maximum of 65% of its battery Maybe that is what you were referring to, or does Tesla do the same?

Unless you have a large expensive battery, most people are just going to charge to 100%. What we all can do is not to do a deep discharge and run the battery dry. If it has less than 50% charge on it, go ahead and fill it up.

Maybe a picture will help impress on you the importance of this?

2old

C58 (sounds like an explosive) --- Tesla does the same using the 20-80% battery capability. I don't discharge deeply either mostly since my battery is charged fully before each use and I haven't traveled more than 16 miles.

350htrr

Yea, so... How does anyone pick what level to charge a battery? Most/All batteries get charged to what ever level the company decides to charge the battery, as all chargers come with the product/battery. My car battery doesn't, but many battery chargers allow me to pick the charge by the type of battery, but that's it, no max level charging option...

2old

Grin (ebikesca) has a charger that can be set to a desired voltage. I've heard that em3ev will adjust the voltage on chargers for batteries that he sells.

chas58

Good question.


Like I said: "most people are just going to charge to 100%"


2old has the correct reply. If your battery costs over $1000, you would be well off to get the ebikes.ca or EM3ev chargers that can be adjusted to the depth of charge. For a $500 battery, maybe not.

(BTW, not all chargers come with the battery, nor do all batteries come with a charger).