Question about LVP in the S21A (12 mode)

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1

It took 3 or 4 times seeing this happen before I figured out what’s going on, but I don’t see any docs for the biscotti-like 12 mode firmware in my S21A that indicate this behavior, so it’s a little surprising.

I keep this S21A in mode group 7 with mode memory on. It has lived on the handlebar of my commuting bike for the last few weeks. After about 5-6 hours of riding, bike strobe stops, and it just goes to a medium-ish solid on. The first time, I thought maybe I had bumped the button and changed the mode, so I tried to get back to bike strobe, and it wasn’t there. After I charged the battery, it was back to standard modes for mode group 7.

I’m playing with it again now, and it has a L-M-H (probably all lower than normal), party strobe, and beacon. No bike strobe. It was in bike strobe when I started my ride to work this morning. $10 says after I charge the battery, mode group 7 will return again.

I don’t see any docs that say LVP has a limited set of modes (and maybe even depends on the current mode group). Does anybody else’s S21A do this? I don’t see beacon in any of the normal mode groups, so I guess it’s a bonus you only get when you let your battery get to about 3.1 volts.

2

I put the battery back in at 3.5 v, and the “beacon” mode is a battery level indicator mode, I think. Instead of 1 flash, it’s now 3 flashes. And bike strobe is back already.

Interesting.

3

At around 2.8 volts the low voltage warning triggers which is I think one flash every 5 seconds at a much lower brightness

4

Mine’s never gotten that low, because bike strobe disappears around 3v.

5

Bet you haven’t measured it under load though, only its resting voltage. Sounds like the correct behavior since before the low voltage warning it reduces to low output.

6

Which battery are you using?

7

Group 7 is: 0.1, 1, 10, 50, strobe, biking, battery-check, SOS.

So you lost a level and the biking mode went away? What about the SOS mode?

Seems strange that the modes would change due to low battery voltage, but I’ve never tested it with my Convoy Biscotti drivers.

8

It’s not biscotti anymore, it’s a copy so behavior is a little different

9

Interesting, but it appears to have the same functions and options.

10

Yep, just in the charger. It’s usually still around 3.1 volts, actually, when I charge it. But that’s sometimes after quite a bit of riding on “medium” or something.

11

No SOS mode, but apparently a battery level mode, at least when the battery is less than 100%. The cheat sheet is just copied from Biscotti, but it looks like there are some changes that aren’t documented.

12

yeah my S21A also did that… i figur it out when the batt is 50% and lower… bike stobe is just like 50% flat… maybe when strobeing its goes beyond 100% power… so its preserve batt when 50% and under

13

How do you change modes on the S21a…I just got one with the Osram led and it’s got 5 leveled of brightness then a strobe, beacon and something else then back to lowest level. How do you change modes & does it have a battery voltage check function?

14

Just Google Convoy Biscotti firmware and instead of 10 taps it’s 20+

Here’s my video for my customers 12 Groups Firmware - YouTube