Issues with inexpensive CREE headlights on Amazon, eBay

[Ravi Kempaiah]

A pair of good lights on E-bike is essential.

I like high-quality products from Supernova and Busch & Muller but if you want few of them for different bikes, the cost quickly goes upwards of $250..

I have been experimenting with some inexpensive Cree XML lights.
CREE is a company that makes high-quality LED and complete lighting systems and their XML series of LEDs are widely used in many bike lights that can be bought on Amazon and eBay.

There are a bunch of Asian sellers are Amazon (Nice customer service from Nestling!) and I have few purchased few lights from them. These lights represent a tremendous value but often the sellers leave out an important piece of information i.e., the battery packs don't have BMS and use B-grade cells. Even then, they last an year or so which is pretty good considering how much lumens they put out.

So, one of my earlier lights started showing drastic loss in capacity and I sent them an email asking what could be the problem and the guy replied back saying, you shouldn't charge it for more than 3-4 hours. Because there is no BMS, the charger won't shut off (change from red to green) once the packs reach the limit voltage!! Any overcharging on Li-ion packs is going to degrade cells super quickly and no wonder mine conked out..

If you're handy, you could follow this procedure (the procedure is highlighted in one of the reviews) and replace it with A-grade cells like Panasonic NCRB and that would give almost 5hr run time.

Here is the awesome Supernova M99 Pro that will be released in the US soon. (costs upwards of $400!! )
Stromer ST2-2, Trefecta and few other bikes use them...

 

[George S.]

http://www.amazon.com/DROK-Converte...60307923&sr=1-13&keywords=60v+dc+dc+converter

I have one of these which will simply convert the voltage from my ebike batteries down to the 8 volts or so my light requires. The big gripe is the batteries they supply with these units and, real world, no one wants to charge batteries all the time. Bad designs, really, the lights seem to be OK. Mine has a huge heat sink, or is, a huge heat sink.

With a DIY I can use a splitter and just plug this converter into the battery. I think DIY vendors sell multi-voltage lights that do the step down conversion from the battery. But that's just not DIY enough for me.

I can actually use this converter to run the 12 volt systems in my travel trailer. So I can use the ebike battery as an RV deep cycle type battery. You see massive LiFePo4 batteries, like 48v and 30 amp hours. The batteries are way too heavy for a bike, but they are light relative to lead acid batteries. There are 48 volt inverters to make A/C, and little converters like this to make DC, 12V.

Lots of fun, if you are into it.

 

[Cameron Newland]

My 8-cell 8400mAh pack that came with my 5-LED, ~4500 lumen headlight probably doesn't have a BMS on the pack, however, the charger that mine came with most certainly stops charging it once it hits ~9.5V (it's an 8.4V nominal pack), so I can charge mine overnight without any problems. My batteries have never over or under-charged.



http://www.amazon.com/SecurityIng-W...1&redirect=true&ref_=oh_aui_search_detailpage

I have had trouble with the barrel jack connectors, though. Basically, if you pull the connectors apart while holding the wire sheath instead of pulling on the connectors, you'll end up weakening or breaking the soldered bond between the wire and the connector's terminal. I bought a solder kit for $15, cut the barrel jack connectors off, then re-soldered the positive and negative wires to the barrel jack connector's terminals, and now I'm really careful when disconnecting the connectors between the headlight and the battery and everything has been fine. I think my soldering was more reliable than the factory connector soldering.

 

[EddieJ]

http://electricbikereview.com/community/threads/what-kind-of-headlight-do-you-use-or-recommend.2335/

 

[NormL1]

Ravi, could you not just add a PCB (http://tinyurl.com/q86drgz) for what the cells are and change to a charger (http://tinyurl.com/pkkbwt9) for that PCB? Or if there is no room to add a PCB, you could use a balance charger from the R/C industry and set it for exactly what you need. I use this one for my testing and goofing around http://tinyurl.com/j2zplua It is a bit much for what you want, but, there are other cheaper ones.