RESET DURING DIVE

[Yeti42]

OSTC3 S/N 2176 Firmware Version 1.22

I bought a OSTC3 and did a couple of shallow dives in the UK, both CCR and OC. Original Battery, showing 25% remaining, strangely this 25% remaining did not change during these two initial dives nor the subsequent 3 dives in the Red Sea. It performed fine.

I have just returned(11 April 2014) from the Red Sea where on dive 3 of the trip it reset completely during a dive losing all deco information, history of that dive and all of the logbook. It started a new dive underwater. It had retained the set up data, it still showed CCR mode, 32% DIL and the correct set points. On surfacing I checked for any water ingress(none found) and fitted a new battery (SAFT LS 14500) and performed a battery reset. The OSTC3 then performed OK to date(17 dives). On fitting the new battery it initially showed 100% remaining but within a few seconds went to 75%. Since then the battery remaining has decreased as I might expect and now stands at 67%.

The dive on which it failed went like this.

Enter water, OSTC3 switched on OK working fine. Spent 10 minutes descending and looking at the coral at around 20m. Set Point switch OK. Came to a ridge and started to ascend, checked OSTC3 and seemed fine and agreed with the deco info on the APD Vision I was using. Got to the top of the ridge around 7m, checked the OSTC3 to find it had reset to a new dive and the depth indicated was changing rapidly. I reverted to the APD deco computer for the rest of the dive. After the reset I decended the ridge to about 14m and completed the dive.

Attached are photos of the log pages. This dive is still on the OSTC3 but unfortunately has been over-writen on the APD Vision so I cannot send you details to compare. I still have the original battery if you need it, and/or the OSTC3, to test.

I am not about to take this computer to 50m just yet and reserve the right to return it for a full refund as I consider it to not be of merchantable quality.

I also noticed a screen update fault. If you put in a new battery (SAFT LS 14500) and do a battery reset the displayed battery remaining goes to 100% and then after a few seconds to 75%. However the display reads 75%% (two % symbols). I assume that is just a minor bug in the screen refresh for that field.

[heinrichsweikamp]

Dear Yeti42,

Battery percent are computed based on the theoretical consumption and updated every second. That means the OSTC3 knows how much current the unit requires due to the ambient light and active components like the compass or the optical link. This is summed up until 8,64Wh energy is reached (=0%). In cold water conditions or when no new batteries are inserted there are four additional setpoints for 75, 50, 25 and 0%. Once such a threshold is triggered the battery stays on this value (and starts counting down from there).

If you insert a used battery and tell the OSTC3 that this a new one, the calculations will be wrong. With he three additional setpoints the battery calculations will be at least 75, 50 and 25% (Better then nothing).

The failure is most likely due to an empty battery. _Maybe_ the battery was not ok or lost contact during the dive? From here, I can't see that the unit has some kind of hardware defect but it does not look like such an issue.

The double "%" is indeed a bug in the firmware - will be fixed with the next release.

As for returns or refunds - according to our records this unit has been sold through a dealer. Get in contact with your dealer about this.

Regards,
Matthias

[Yeti42]

Thanks Matthias,

Thanks for the explanation of the power monitoring. For your info the battery in the device at the time was the one it was supplied with.

What do you think is the reason that the dive log was reset to zero and all past dives were lost? I would not expect this to happen unless the dive log was in volatile memory. It does not happen when you change the battery. The dive log currently shows 18 dives with the dive after the reset as the oldest, however the Information page shows 29 dives.

Also, very shortly after the reset the dive log shows an instantaneous ascent to the surface and return to 7m. This did not happen. Any ideas what might have caused that?

[heinrichsweikamp]

I assume the interrupted dive did corrupt the logbook memory pointers. I'd recommend a "reset logbook" from the reset menu (You'll need at least v1.24 to do so) here.

Regards,
Matthias