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Frequently Asked Questions

We've compiled some of the most frequently asked questions. If you want to know anything about batteries and why it is so difficult to provide a universal standard, our good friends at have tons of great information. Hopefully here in early November we will catch up and take each different bike light we sell and attach the different mAh batteries to see how long each will provide you with light. Of course the larger capacity mAh batteries we already know from past experience will give you extended light, but what we want to find out is just how much and whether it makes economic sense to buy a big bad boy or have two smaller batteries. We'll be back soon with the answers!

What's the difference in the rechargeable batteries?

Rechargeable batteries for bicycle head lights (lamps) are typically 8.4 volt and are rated in mAh, which is milli amp hours, or how much current it will deliver in an hour. Easiest way to think about it is as long as the volts are the same and the batteries have the same draw for current, a higher mAh battery will last longer. Kind of like if you have the same model of cars and drove them at the same miles per hour, the car with the bigger gas tank holding more gas would get you further up the road. Rechargeable batteries work the same way. If you have a 4400 mAh battery pack rated for 8.4V powering our 5000 lumen light (TCM430) on high power, you'll get about 1-1/2 hrs, and an 8000 mAh battery pack also rated for 8.4V, with the same light on high power you'll get almost double, just shy of 3 hours, so the higher mAh will deliver 8.4 volts but will be able to deliver it for a longer time. Bicycle head lights come in different ratings, and it is more to affect the price. Thus if the lamp has the same construction with the same CREE LED lights, but the only difference is the rechargeable battery, go for the higher rated battery because you will have to recharge it less often. Make sense?

Can you tell me how much extra time I'm getting with the larger capacity batteries?

Glad you asked! We are currently running tests on our replacement batteries, both generic and by Trustfire, in the different mAh ratings to see how much of a difference, along with how long they will generally stay lit with the battery that comes with the light. For example, the TCM554, which is a 2400 lumen light with 3 CREE LEDs with a 4400mAh battery on high power lasts about 2-1/2 hours (much longer on lower settings). The very same light with our generic 8000mAh battery lasted over 6-1/2 hours. Our TCM430 which is a 5000 lumen light with the 4400mAh battery lasted about 1-1/2 hours on high power, but almost doubled that with the 8000mAh battery pack. That's with it on high power! Most don't ride on high (blinds oncoming traffic) so it's going to last a long time on a lower setting.

Many of the lights look the same, what is the difference and how does that affect the price?

Yes, quite a few use the same high grade aircraft grade precision aluminum housing and glass lens. What separates them and has a big factor on pricing is the number of CREE LEDs in the unit, the software controlling the lights power (check out the more expensive lights and all the options they have), the number of hours they are rated (some are at 50,000, 80,000 or 100,000 hours), how bright the LED's are (lumens), and the capacity of the rechargeable battery (the larger the mAh the more expensive the battery but the longer the light will stay lit) and whether the light controller is on the light or can be mounted on the frame or handlebars. All of the lights have a 1 year warranty and batteries are rated for approximately 500 recharging cycles.

What is the best way to charge a Lithium-ion Battery?

Partial and random charging is fine; lithium-ion batteries do not need to have a full charge. ALWAYS keep batteries cool. Heat is the enemy! Do not leave them sitting on the dash of your car, or left out in the sun on your bike.

Is it best to completely discharge a battery?

No, prevent full discharges if possible and apply a charge after a full discharge to keep the protection circuit built into the battery alive. Lithium-ion batteries do not develop memory like alkaline batteries so they do not need to be completely drained.

What is the best way to prolong my bike battery?

Heat is the enemy of Lithium-ion batteries. Keep it cool and batteries last longest when operating in mid state-of-charge of 20-80%. Prevent ultra-fast charging and high loads, which won't be a problem if you use our chargers that came with your light or are found on our web site as replacements.

I won't be using my bike light during the winter months, what's the best way to store the battery?

Store the battery at about 40% charge in a cool place (40% SoC). Of course without a tester our recommendations would be to drain it about half way (over time you'll know about how long it lasts).

What is the best way to dispose of my bike battery?

Of course always the best way is to take to your community recycle site. But unlike lead acid batteries, Lithium-ion batteries are much kinder and safer on the environment.

What are recharging cycles and how many should I get?

Our bike rechargeable replacement batteries generally will give you around 500 charging cycles. But this is a very, very broad general statement because there are a lot of varying factors that will cause that to fluctuate. Such factors as to how frequently they are charged, what degree of charge the battery gets (whether it's a full or partial charge), the environmental temperature it is used in and stored, and a host of other factors. We will not guarantee a set number of cycles because of all of these varying factors. If you really want to dig into all the technical stuff, our friends at have some great information here:

Some information adapted from

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