battery change

[jp01000]

from what percentage advise you load a preventive battery replacement ?

[Ludo]

That's a good question.
I changed my first OSTC3 battery with less than 10% and finished the dive without problem.
Last month I started a dive with 34% battery. When doing the safety stop, the OSTC3 was warning about 10% battery and it didn't make it until the end of the dive. (by the way the log doesn't mention that dive at all since it was not properly finished).
That was with firmware 1.88
Friends having the same hwOS version are also suspicious about it's battery consumption.

Any guidance an battery preventive replacement?
Is battery consumption / non linearity a known issue with recent firmwares?

BR
Ludo

[heinrichsweikamp]

What battery was used?

regards,
Matthias

[Ludo]

Hello Matthias,

I was using the same battery as the original: Saft LS 14500

Regards
Ludo

[divejy]

I dove last Saturday with my sport with 35% battery (14500) left, after a hour dive, battery showed 10% and during surface interval (less than a hour), battery gone and I have to replace by a AA battery temporary for my second dive.

So, how accurate of battery marker and how we rely on such battery indicator.

Any suggestion?
Thanks

(Sport with 10.20 firmware)

[Anonymous User]

Hello,
2 weeks ago I dived my sport in 5 degrees C and started with over 50 %.
After 65 minutes with 10 minutes deco I had only 10 % Battery.
So I was happy to finish the dive with a running computer...
Battery before was better and I changed with 34%, dive was compereable...
Best regards

[Ludo]

Looking back in my log book, I've been diving almost 3 times longer with my first Saft LS 14500 than with the second.
Many firmware upgrades have been released in the meantime, could it be that latest firmwares are much more battery consuming?

[heinrichsweikamp]

Hi,

No, the current consumption is almost unchanged and is regularly checked before we release anything (Sleep mode and active modes). Screen brightness is the major factor to battery life. Also the (active and displayed) compass adds a small increase in current consumption. (Active) Bluetooth, too (Of course).

Regards,
Matthias

[Ludo]

Thanks Matthias for confirming such critical parameters are checked from release to release.
I have an OSTC3, so no Bluetooth, and the screen brughtness parameters are always set to the minimum.
I hardly use the compass.

So consumption remains a mystery.

Regards
Ludo

[aries]

Hello, I am a happy new owner of an OSTC3. I'm wondering if it's ok to use a 4.2V AA rechargeable Lithium battery? I noticed sometimes after a full charge the voltage could peak as high as 4.4V+, will that damage my OSTC3 ? Thank you.

[heinrichsweikamp]

Yes, 4.4V (or even 5V) is no problem.

Edit: A Lithium battery peaking to 4.5V? Are you sure your charger and/or volt meter is correct?

Regards,
Matthias

[aries]

Thank you Matthias. Yes this Lithium AA goes up to nearly 4.5V. I will take a picture next time and post here.

[Maes]

Hello Matthias,

I dive with my OSTC Sport.

After the original battery I used a AA 1,5V battery from energizer "Ultimate lithium".
I did 25 dives with this battery (starting in may with dives at 10°C and ending now with dives at 20°C).

My comment is about the battery indicator.
for my 18th dive it was 76% remaining power after dive.
for my 20th dive it was 73%
for my 23th dive it was 62%
for my 24th dive it was 44%
for my 25th dive I started with 42% and during the dive I receive an alert 0% remaining power!
I was able to finish my dive but the screen was difficult to read.
Strange isn't it?
Do I have to recommand to change the battery when indicator is lower then 50% ?

thanks

[heinrichsweikamp]

Hello,

When the battery voltage drops below 1,1V the unit will switch to display 0% battery, when the voltage drops below 0,9V the unit will shut down. I'd recommend using the "ECO" screen brightness when using 1,5V batteries.

regards,
Matthias

[Maes]

Thanks Matthias,

Yes, the problem is that the drop off is very rapid.
From logbook :

23Th dive : voltage at end 1,41V
24th dive : voltage at end 1,30v
25th dive : voltage at end 1,00v

The limit for that kind of battery could be 1,35v if it is below change the battery div
Theire are not that expensive and 24 dives with one battery is good for me.