Question Computer battery changing

[1070man]

I have a Shearwater Perdix 2 and a Sherwood Wisdom 3 I use as a backup. Wondering how often everyone changes their batteries in their computer (and transmitter when applicable)? I know alot depends on how much you dive, but as a general rule, do you change yours when it shows low or maybe you do it at the start of dive season?

Just wanting to get some ideas. Here in VA, unless I go away on a trip, dive season for me is typically May through October.

Thanks for your input.
Brian

 

[tursiops]

I have learned to trust the Perdix battery indicator, so for causal one or two dives a day I change it when it shows low. There is always enough time left to finish a dive or two. The exception would be if I'm on (say) a liveaboard and planning 5 days per day, and on dive one it shows low. I don't want to lose my N2 status! So if it has been a while, I change it before a major trip. the cost is inconsequential.

 

[inquis]

The exception would be if I'm on (say) a liveaboard and planning 5 days per day, and on dive one it shows low. I don't want to lose my N2 status!

Conveniently, the Perdix will retain the N2 status during a battery change. Pop in a new one during the SI and carry on. (There's certainly no harm in being proactive, though.)

 

[NachoMan]

Same as stated above. The battery level indicator is reliable, but I always carry spare batteries in my SAD kit, including the CR-2 for the Swift transmitter.

 

[tursiops]

Conveniently, the Perdix will retain the N2 status during a battery change. Pop in a new one during the SI and carry on. (There's certainly no harm in being proactive, though.)

That's true, so long as you don't take too long to change the battery. While the battery is out, SI is not being tracked. So the good news is the error is on the conservative side: the real SI will be longer than the one measured by the computer.

 

[inquis]

FWIW, I have had my Petrel show the yellow warning during a dive, finished that dive, and did another with it showing red. (Inconveniently, I had given my spare battery to someone earlier in the day. I wasn't worried, since I had 2 computers.)

My point is don't freak out if you see the warning. Plenty of juice to finish the dive. ETA: this was an Energizer Lithium battery in 62 *F water.

 

[davehicks]

Use the recommended Energizer Lithium batteries in the Perdix. Do NOT use regular alkaline as they will leak eventually and damage your computer. Be sure to remove the battery from the computer during your off season. (Doubly important if you use Alkaline cells.)

The Energizer Lithium's will last for around 50 hours of diving in the Perdix.

 

[tursiops]

The downside of Energizer Lithiums is when they start to deplete, they go quickly. So you don't get as long a grace period once you see the Low Battery indicator. However, they are what I use, nevertheless.

 

[Divin'Papaw]

I change my Perdix 2 batteries approximately every 6 months or sooner if they start to consistently show yellow. I never wait until they are red.

On my transmitters, I replace all 4 of my transmitters annually.

 

[clownfishsydney]

I change mine when it shows low battery. Except, if I am going on a dive trip for a few weeks, I will put a new battery in before the trip. Then, when that one finally gets low, go back to the previous one. Works well.