Battery Charger Heads up: something to remember as you become a long-term owner

[Jeffrey Scott Will]

I've been an owner of the KS 14c (500w) for the better part of a year now, and I'm happy to report that through *daily* rides / commuting, I haven't had any mechanical issues. Still running like a champ! A few months back, however, I noticed that it seemed to be getting drastically less voltage per charge, but I chalked it up to colder winter weather. But then I saw that I wasn't actually getting a full charge even when showing a green light on the charger. Many times it would not be charged fully and the battery was only ~75% charged. I was beginning to think that my daily hill climb/descent had taken it's toll on my battery, but then I remembered that people have warned in the past that these chargers are generally shit and do no last long.. so I ordered another one. And now it's like a brand new wheel again! I had forgotten what it's like to ride on a full charge.

I'm on my 4th charger now between the two wheels I own! So before you panic that your battery seems to be weakening, try a new charger. They don't last long.

[esaj]

16 minutes ago, Jeffrey Scott Will said:

I've been an owner of the KS 14c (500w) for the better part of a year now, and I'm happy to report that through *daily* rides / commuting, I haven't had any mechanical issues. Still running like a champ! A few months back, however, I noticed that it seemed to be getting drastically less voltage per charge, but I chalked it up to colder winter weather. But then I saw that I wasn't actually getting a full charge even when showing a green light on the charger. Many times it would not be charged fully and the battery was only ~75% charged. I was beginning to think that my daily hill climb/descent had taken it's toll on my battery, but then I remembered that people have warned in the past that these chargers are generally shit and do no last long.. so I ordered another one. And now it's like a brand new wheel again! I had forgotten what it's like to ride on a full charge.

I'm on my 4th charger now between the two wheels I own! So before you panic that your battery seems to be weakening, try a new charger. They don't last long.

Maybe it would help not to buy the cheapest charger..?   Don't know if any of the chargers coming with the wheels are *that* high quality really?

[Jeffrey Scott Will]

The one that came with my wheel was a 2 amp fanless model. It seemed nicer than the ones I had in the past with my Airwheel. But honestly, I don't know how to find one that is supposed to be high quality. They all come from China and have dodgy specs and translations, and end up sending you something different than pictured.

Do you have any advice for shopping for a nice charger that will last?

[esaj]

8 minutes ago, Jeffrey Scott Will said:

Do you have any advice for shopping for a nice charger that will last?

Unfortunately, nothing very conclusive... with "enough" knowledge (which I don't claim to have ) and proper electronics measurement gear (like oscilloscope, high quality multimeter, electronic load) you could probably tell pretty fast which is good and which is not, but getting such equipment and "expertise" just for buying a single charger is a bit unrealistic

However, I'd expect (but don't know for sure) that you should be able to find a domestic company that specialized in batteries or e-bikes or such, and get a ready-made charger from them without having to second-guess the quality. Probably it will be a lot more expensive than the chinese ones, though.

Just as an example (that's way overkill with the power ):  http://www.batteryspace.com/Universal-Smart-Charger-18A-1500W-for-SLA-LFP-Li-Ion-Battery-Packs.aspx

 

[dmethvin]

I guess I've been lucky. I have 4 working chargers now: a cheapo 200w fan-charger that came with the 14-inch, two 200w fanless ones from Firewheel, and a 5-amp monster with a loud fan that Cranium recommended. They all seem fine. I carry the cheapo charger when I ride because it's the lightest. 

As far as charger failures go, it's probably better for them to fail by delivering a low voltage rather than a high one! The 5-amp charger is nice because it charges so much faster and seems like sturdy engineering, but you don't want to be in the same room with that fan going.

[Nevin@Tec-toyz.com]

That is strange, 4th charger? I know you stated between two wheels, is it two changers that went bad or just one? I know I seen a video somewhere where of someone opening the charger and adjusting the voltage output because the charger was turning off before it even got to 67.2 volts. If my memory serves me right, they used a regular multimeter to test the voltage output of the charger and thats how they found out that the charger wasn't giving the correct voltage to the wheel. And in turn wasn't charging the wheel to 100%. After opening up the charger and making an adjustment on the voltage regulator, it worked fine. I'm sure someone has seen this video too. You might want to search the web for that video.  All my chargers still work just as they should. I had 1 since March, 5 since August 2015, and 1 since November. All are fanless. That video was showing the adjustment for the same fanless charger. I also have 2 fan chargers as well, can't give you any comparison though since I don't really use them. 

[dmethvin]

3 hours ago, NevNutz said:

If my memory serves me right, they used a regular multimeter to test the voltage output of the charger and thats how they found out that the charger wasn't giving the correct voltage to the wheel. And in turn wasn't charging the wheel to 100%. After opening up the charger and making an adjustment on the voltage regulator, it worked fine.

That is definitely the most likely reason they wouldn't be giving a full charge. There is usually a small trimpot, a variable resistor with a screwdriver spot on top, that you use to adjust the voltage. On some chargers there may also be other adjustment trimpots so you might need to experiment with TINY turns noting the original position and see what happens to the output. For the smaller chargers I'm not sure how to open them, there may be screws under the labels or rubber feet. For the big one, Cranium did a nice teardown: