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4iii power meter guzzling batteries

I wonder if anyone has any experience of, or can suggest a solution for, a 4iii non-drive-side crank power meter eating through batteries like there's no tomorrow? I bought this meter secondhand last year and it's been good as gold until the last month or so, now it needs a new battery every time I go out, it lasts fine in use (6 hours being the maximum ride since the problem started) but when I go to use it again the battery's dead or at best lasts half an hour then dies. I'm using Duracell CR2032 batteries and I'm always careful to turn off the head unit (Garmin Edge 800) when the ride is over, and I take out the battery when I'm on Zwift, so I'm at a loss to know how it is using up the battery power (claimed life from one CR2032 battery is 120 hours). I can only guess that it might still be transmitting on Bluetooth to some other device in the house, even if the head unit is off? I'd be very grateful for any advice, it's out of warranty and thus far (after a month) 4iii have not answered my queries.

 

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9 comments

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Louison | 9 months ago
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Hello Harris,
your problem is solved?
 

 THx

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Rendel Harris replied to Louison | 9 months ago
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Yes, it was as mark1a suggested below, it was connecting up with apps on my phone that I hadn't shut down so wasn't turning off.

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mark1a | 2 years ago
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Couple of things worth a try:

- make sure that any phone apps paired with it are unpaired, in case it's being kept awake.

- soft reset it by flipping the battery round 180 degrees and re-insert for 5-10 seconds, and back again.

I have a few 4iiii power meters and on the whole they're very reliable. I did have one issue where it was reading very high and wouldn't calibrate, that battery tip was advised by 4iiii tech support and it did the trick.

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Rendel Harris replied to mark1a | 2 years ago
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I'll try that trick if it doesn't behave, but I think you may have put your finger on it – I completely forgot I had the 4iii app on my phone, having only used it for the original set up, I wonder if it's been automatically pairing without my knowing it? That would certainly explain the way it is getting through batteries, I've removed the app from my phone and we'll see what happens next time I take the roadbike out at the weekend. Many thanks.

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duncanap | 2 years ago
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Some random suggestions - 

Could be worth trying to clean the contacts - sometimes corrosion can add significantly to resistance in the system. Makes it look like the battery is dead even when it may not be. 

Have you tried the "dead" batteries in another device after taking them out? If they have life left then it does point to the contacts or another more tricky internal fault.

Have you changed battery type recently? Maybe you have a duff batch of cells?

Also worth noting how much temperature affects battery life, cranks get cold.....is this a problem that has started when the temperature dropped?

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Rendel Harris replied to duncanap | 2 years ago
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Thanks, useful suggestions. I've cleaned the contacts with contact spray and there is no visible corrosion, and I've tried it with multiple batches of batteries. Good idea about checking battery life, I've got some CR2032-operated lights I keep in my jacket as emergency backup, I'll try the next ones to fail in those.

Temperature has been cold but not freezing and for sure that could affect battery life but surely not cut it from a predicted 120h to a max 6h?

Many thanks for the reply!

 

 

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check12 replied to Rendel Harris | 2 years ago
1 like

Maxell batteries on eBay are good, some other brands are rubbish

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duncanap replied to Rendel Harris | 2 years ago
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one last thought, a lot of power meters (garmin for example) wake up with motion, do you store the bike somewhere it might get jogged/knocked? Kids who like to spin the cranks (I would put my hand up to that, its almost irresistible if the drive train is clean).....

Sounds like your sneaky blue tooth app is most likely culprit though. Technology is too clever and helpful by half now.

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Rendel Harris replied to duncanap | 2 years ago
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Thanks, good suggestion but that bike is right up on ceiling hooks well away from any knocks!

Yes, half the time I have no idea what tech is doing on my behalf due to some preference I expressed two years ago...

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