Hi folks,

Bought a second hand Spider Eyes with big battery a couple of years ago off of here. Done great, used relatively infrequently (don’t get chance to night ride too often), but this season has started to malfunction.

After about 30 minutes on full beam, it automatically kicks down into lowest setting. Give it a few minutes and you can cycle back up to full power again, but then after only a few mins will go back to low. Longest I have been out is about three hours, and it would keep this up for all of that time. I have never drained the battery fully.

So – is this an issue with the light? Or is it a battery issue?

How might one solve the issue?

Guidance appreciated, was about to spend with smudge on a new pack, but your input appreciated.

Cheers all.

have you given the battery a couple of full cycles (run till flat then fully recharge)?

(edit, just notied that you haven’t, I’d try that)

though it sounds like its just kicking down to protect itself against heat buildup.

1 of 2 things IME:
1: light overheating and going into thermal protection (as above). It’s possible to reprogram it so the trip point is higher.
2: the battery is on the way out. How long does it take the charger to show red (charging) to green?
Had #2 on my battery last year. Sent it back to smudge who rebuilt it for me/replaced the damaged cells.

I’d go with 2.

OK, might be a stupid Q, but how do I drain the battery fully? I ain’t got the legs, or tolerant enough family, to ride all night till it runs out… 🙂

If I just leave it on stationary, it does get warm, so… put it in the fridge? Hang it out the window on a cold windy night?

BTW, not aware of any changes in thermal properties, light is still completely cool when riding so this does suggest battery issue.

drain the battery fully by leaving the light on till it stops working

Re charge

Warm will mean obviously so I imagine – well above warm to the touch anyway so unlikely to be that and

I think troutie used to set the thermal trip at about 60-70° so it can get fairly hot before tripping. It does sound more like the battery being the cause.

that does sound like the thermal protection kicking in

but can you check the battery voltage with a multimeter when it has dimmed down .

the light only needs 10 ish volts to run properly and the battery should never get down that low
lowest it should get is 13 volts so it may be some cells have given up under load but are recovering when resting

I can check out the light head for you. but you would need to get Smudge to check the battery and charger

to discharge fully set the light up outside and make sure there is a good airflow over it and leave on til it dies then check the voltage you might need to briefly connect the charger to restet the protection circuit

one other thoughtbis the driver circuit has become detachedfrom the heatsink this would explain the light being cool when it happens

Heat sink compound has dried out perhaps?

Thanks guys. Will dry to discharge the light first, see if that helps. Troutie – thanks also, will report back findings.

discharged the battery fully (took 11hrs, cycling it back to high whenever I remembered).

Recharged the battery (don’t have the means to test voltages), went out for a ride, lo and behold it’ll stay in high as long as I want now. Weird. What the heck is going on there with the he battery?

How should I best store it between rides?

Kev