New Olight SR51 problems

[WoolyLamb]

Howdy all, Just received my new SR51 with 18650's from Battery Junction three weeks ago. I charged the light and showed off to friends and family. Everything seemed to work great, High/Low power and strobe.
I took the light with me on a camping trip, halfway through the trip I put the power on high for no more than 20-30 seconds, then the light shut off. I thought it might be the batteries so I replaced them with a new set of fully charged 18650's. Same problem, on high for 20-30 sec. light shuts off. No sign of heat, lens was still cool as well as aluminum body. Light has no problem on "Low" power.
Battery Junction has issued me a RMA number and has fantastic customer service.
I know this is a new model and was curious if anyone else has had similar issues.
Thanks in advance.

 

[goose2283]

Welcome to CPF. I'm sorry your first post had to be one asking for help.

That sounds to me like you're tripping the protection circuit on your batteries. The SR51 is quite a high-powered light, so I would expect that lower-end batteries, or mismatched batteries could cause trouble with it.

I only use Redilast 3100s in mine. I balance charge them with a hobby charger, and they have never (not even once) been charged or discharged apart from each other. Are your batteries perfectly matched? Are they quality, high-capacity cells, such as AW 2900s or Redilast 2900/3100s?

For the record, I have a Spark SL6-740NW. I use either Tenergy 2600s or TrustFire 2400s with it. It will consistently trip the TrustFire protection circuit on turbo mode. I would not consider the TrustFires to be a top-quality cell, and will only use them in single-cell applications.

 

[WoolyLamb]

Thank you goose for the response. I think you may have hit the nail on the head!
I am very familiar with the lipo batteries needing to be balanced and charged together due to radio control planes that I fly. Im unfamiliar with using and wiring the 18650's on the hobby charger. Due you have any diagrams or instructions that would help me?

 

[goose2283]

I'm glad you're familiar with RC LiPo care and feeding. Here's a thread that shows what a few people have done: http://www.candlepowerforums.com/vb...ech-Tricks-Homemade-Balance-Charging-Cradles. I did something similar to this - I had a lousy charger from DealExtreme which doesn't have a true CC/CV 2-stage charge. I pulled the guts out of it and wired it up as a 2S balance charger, essentially the same as described in that thread. For charging single cells, I have a small bar clamp from Home Depot that I've modified with a JST connector and a couple of brass tacks as contacts.

The only downside to the hobby charger is that unlike a dumb charger, it can't reset the protection circuit on your cells. I should also mention that the LiCo cells that are common in this hobby are charged as LiPo, not LiIon with a typical hobby charger.

 

[qwertyydude]

You may find unless you got a different brand of batteries with a better protection circuit, the same thing will happen. If so you need better quality cells, I know the AW cells can run higher loads. You can also remove the protection circuitry but I don't recommend that unless you really know what you're doing and know not to let the batteries run down anywhere close to dead. It normally won't be a problem with 1 cell light but multiple cell regulated lights can be trouble as you won't know when the batteries are dying til it's too late.

 

[WoolyLamb]

Great thread on charging/balancing, Thank you. I feel like im home!
I have the UltraFire BRC 18650 3000mAh batteries. Two questions:
1) As long as I have the opportunity to return the light, do you think I should get a replacement?
2) Are the batteries im using good, bad or otherwise. Do you think ive already destroyed them using the "dumb" charger?
Thanks again for all this great information.

 

[qwertyydude]

Your batteries are definitely not 3000 mah. I'd give them 2200 mah tops as that's about average for what I see with all my *fire cells. You likely didn't do damage but it's those protection circuits, they'll cutoff on some of my cells as low as 3 amps. I'd keep the light and get some decent cells like AW cells.

 

[HotWire]

I just bought the Olight SR51. I've been using Redilast 18650s and AW 18650s. No problem like you describe. After I read your post I pulled out some old Chinese 18650 and charged them up. My light's been running about 6 minutes on high with the cheapest batteries. They are not only cheap, they are old. But the light is flawless.... except for the color of the tint. It's kinda green/yellow. I'd suggest you try other batteries, then get an RMA number and send it back. Olight is a good company and will fix or replace your light. Next time you buy batteries get AW or Redilast. I've also had good luck with Callie's Kustom cells, but don't have enough for this light. I'm sure they would work.

 

[cummins4x4]

I just returned my SR51 to GG. It would switch from high to low by itself. When on low it emitted a buzzing sound. Problem started after about 2 hours of use with UF 2600 18650's, never tried it with CR123's. Didn't matter if the cells were fresh. I am now wondering if it could have been the cells?

 

[WoolyLamb]

Howdy Everyone,
Sorry for the delay in response. Just wanted to let y'all know I got the SR51 working just fine with the new batteries. Life is Grand! Thank you all!
Another question for you though regarding batteries: If we are not supposed to store the Li-ion batteries at full charge for more than a day or two, How does one keep the light accessible for anytime and how does one prepare the back-up set of batteries for immediate replacement when the light goes dead?

 

[yifu]

Howdy Everyone,
Sorry for the delay in response. Just wanted to let y'all know I got the SR51 working just fine with the new batteries. Life is Grand! Thank you all!
Another question for you though regarding batteries: If we are not supposed to store the Li-ion batteries at full charge for more than a day or two, How does one keep the light accessible for anytime and how does one prepare the back-up set of batteries for immediate replacement when the light goes dead?

Permanent loss of capacity is around 10-20% per year (voltage remains constant for good cells but the capacity reduces) for fully charged LiCoCl cells and around 3-5% for cells below 3.9v or so. So if you don't mind the 10-20% permanent loss in capacity after a year then don't store them at full charge. I personally replace all my cells after a year and a half so it's not a problem.

 

[Brasso]

That's whats so great about rcr's. Don't worry about the power loss, just use them. Keep the spare 6x123 pack at the ready and don't worry about the rcr's.