This is very UN SCIENTIFIC so pardon the lack of. I have a convoy s2 I bought last year along with a nice charger and 2 Sanyo protected cells. The convoy has the driver that will outpout 900-1000 lumens on high. I can’t remember exactly what the specs were on the Sanyos but I bought some of the larger mah cells. I use this light on the handlebars of my bicycle for a bike light and primarily use it on strobe mode only so cars can see me during the day. I am disappointed with the battery life. Again not scientific here but it seems as if I only get 3 hours or so (give or take) on strobe. It might be more accurate to say 3-4 hours. This seems pretty short lived for a strobe when some bike lights on the market say 40 hours on strobe (granted I am sure they have big battery packs). I am thinking I need to buy 2 more batteries and just keep them in my bike bag for weekend getaways. Does this battery life sound normal? It just seems like one battery ought to last a few rides on strobe (without recharging) without the light going dead halfway through a ride.
I don’t have S2 but I have C8 that might be not far regarding runtime?
40 minutes on turbo using 2600mah (xtar protected)
1 hour and 40 minutes on turbo using 3400mah (NCR18650B)
On many lights, strobe runtime is usually 2 times normal output with the same lumens
So, I think 3-4 hours runtime is normal as the strobe output is the same as the turbo
Okay so if I was to buy another Convoy and have a different driver that didn’t have such a high output, say 500 lumens on high, does that mean that the stroke would last twice as long as my strobe currently lasts?
Most likely. But the more precise answer I believe is depends on how many amps it draws.
I needed extra batteries to carry with me anyways so I took a chance on these from Mountain Electronics Sanyo/Panasonic 18650
The batteries I have now are red and have no label on them. I think they are Sanyo. I studied hard when I bought them and bought from Fasttech and made sure I didn’t buy trustfire or one of those counterfeited brands. But I almost think the cells I bought were 3200 mah or something like that. These Panasonics had great reviews. maybe they will have a little better life than what I have now. I bought 4 so I will always have plenty in my bike bag.
If you can solder two wires you can buy just a replacement driver and put it in your light. There's a new version with improved firmware that has more modes, including a 2Hz bike flasher.
The number of 3×7135, 4×7135 etc is the number of chips. Each chip drains 350mA from the battery to power the led. Your current convoy has 8×7135 chips = 2800mA on full power, you can choose that or fewer chips to drain less battery. It won't be much less bright. Personal preference.
Yes I can solder wires and this new driver sounds interesting. I was recently reading where a rapid strobe could trigger seizures in other drivers.
Yes, this can happen. Not as severe but those who are sensitive to PWM are experiencing something similar in their brains and long-term exposure can actually cause them to experience physical problems. IIRC it’s best to stay below 200Hz for flashers to avoid this.
Phil
So if I got the 4x7135 that would draw less than my current board but how bright would it be? Is this the board that would give you around 450 lumens on high? I think 900+lumens is maybe overkill but I don’t want to compromise my safety by going too dim either.
Halving the power drain won't make it 50% as bright, but closer to 60% (the LED will work more efficently). That will shorten its range by less than 1/4. If you're driving fast you could get 8×7135 and maybe carry a spare cell just in case instead.
OK so I ordered the 6x driver. If I am correct that should be around 75% as bright as what I currently have and give me some longer battery life as well? I am going to like having the bike mode as well on this new one.
The light won’t be perceived as 75% as bright, it will probably look just as bright, very close to the old one.
Check out the pics in this thread. Convoy S2+ 7135*3 vs 7135*8 Brightness