52 Volt, 1000 Watt Bafang with Sharkpack - What Are the Limits of Use?

[Madjag]

I recently purchase a Luna Police Bike, 52 Volt, 1000 Watt Bafang with Sharkpack. Awesome bike that I have only ridden 90 miles so far, mostly the 3 times on my commute to work and back (25 miles RT with a 1,600 ft vertical xclimb spread over mostly a 5 mile section of the ride).

I read in the Luna Advanced Charger booklet that came with my purchase that the first 6 charges should be at 100%, however thereafter it's better to charge the Shark only to 80% in order to increase the life cycle of the battery from 400 charges to possibly 1,000 charges. It also says that this is the case unless you are going to go on a long ride for which you can then charge the Shark to 100%

I'd like input as to what differentiates the length of a ride for it to be considered a "long ride".

My Skarkpack starts fully charged at 58.6 volts and ended at roughly 44.2 volts when I get home after my round-trip to work and back. Yesterday, at the end of my my 3rd RT, brought the blue battery bar down to near the bottom, perhaps only one bar/segment left, and that bar indicating just a little battery left alternated between Blue and Red. When I got home, turned off my bike, and waited a minute or two, I turned the DPC14 back on and it was no longer Red but rather had stabilized at Blue and 46 volts.

Questions:
- Does the red bar indicate a "danger zone" for the battery or is it just warning me that I am almost out of juice?
- What is the lowest discharge that the battery can take and still not be injured.....or will it just shut down when it reaches any dangerous level?

I'm interested because with my previous Bionx 350 watt rig, I made it just to work with an empty battery. I kept a second charger at work so that I could charge up the battery for my ride home. The return ride was mostly downhill so when I reached home I usually still had a 1/2 battery charge. This Luna bike with the Sharkpack gets me both ways on a single charge, however yesterday's "Red Zone" got me concerned. How will this perform during the Arizona summer when the ambient air is 80-85F in the early morning and 90-100F at 4pm when I return home? Would it help to have a second charger at work to top off the battery for my return ride, especially since I want to charge the battery to only 80% if possible. Maybe in my situation with my specific commute, I will always have to charge at 100%

One last thought......how long should the Sharkpack sit silent, unused with a 100% charge? Can it safely be 5 days until my next commute? 10 days?

Thanks in advanced to all of you forum members who offer your experience and wisdom.

Peace,
Madjag

[OptimusPrime]

I'm a bit confused. Are you saying you started out with a full charge and at the end of your 25 miles the battery was down to one bar? If that's the case then yes I would probably charge at work just to keep the battery voltage in the sweet spot. And if for some reason you had to make a detour you could.

[ykick]

I’m just not a fan of short-charging packs. What about the time you forget your phone and double back for it? Or the usual road’s closed? Or the wife wants you to detour to the store for something? Or there’s a crazy strong headwind?

In other words, why even run the risk of NOT having a enough charge and running the battery pack into ODDV (over discharge detection voltage)? Is that really gonna help pack longevity?

The way I use 80-90% charge level is to avoid a pack sitting fully charged for more than a few days in a row.

Simply put, when I know I might be going out of town or not riding for several upcoming days, I then charge to 80/90% and set it aside until I know I’ll be riding it and then top it off to 100%.

Newer packs won’t show much degradation from sitting fully charged for long periods of time but as cells age and increased IR sets in, I’ve experienced less drop in performance when following the practice of not sitting fully charged for long periods of time.

Cells don’t need to be 3.85V/cell “storage” charge during sporadic use but just something burned off that top 4.2V/cell down to 4-4.1V is quite beneficial, IMO.

As far as temperature is concerned these cells will perform much better in warmer temperatures. Many of us old-timers know about the "Fall-Winter" drop-off which accompanies using Lithium packs in colder temperatures....

[Madjag]

Thank you electric gentleman.....a second Advanced Charger is in my future.

[Madjag]

I want to thank the forum gurus who answered my question posted above......I bought the 52V Mini charger and now charge at 90% at each end of my communte rather than try to manage a RT on one charge. I hope that this provides me with the longevity that some writers have mentioned can be obtained by doing so. I usually end up with around 50-52 volts still in the tank. Charging doesn't take as long either. When I had a devilish headwind last week, I was sure glad I wasn't pushing my Shark down into the red edge by trying to go round-trip on one charge.

By the way, are all the 1000Watt Bafang bikes Luna puts out as fast as the Police Bike? On a small downhill grade, maybe only 3-4%:



I figured out what you probably already know - Luna is short for Lunatic. I thought it had something to do with lunar, moon, etc.
I'm in !!

[fatEbike.LA]

Luna Cycle is named after Eric's Dogo Argentino, Luna. At least that's what he told me once.