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Suunto D4I - check battery status?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Well-Known Member
Aug 26, 2015
Is there a way to get more specific battery status than the ol “Battery ok” you get when starting Free mode?

I’d like to see percentage if possible. Since it’s a bit of a hustle to change battery, it would such to all the sudden run out when travelling. :/

landshark sa

Well-Known Member
Feb 15, 2011
Hiya Subsub,

TL;DR Take your watch in to have the battery replaced if the battery voltage is below 2.7V. You will require a Suunto PC connect cable and Suunto DM5 desktop application in order to check it.

Also, will any of the waffle below give you an idea of your actual battery status, maybe. Is it an 100% accurate and trusted indicator, absolutely not... but that's all I got at the moment.


In Jan this year my D4i started showing the battery low indicator. Bad time for me as this is just running into the best time of year for Yellowtail spearfishing in my neck of the woods. So I made up my mind to ignore it until it either died or I had a gap to take it in to have the battery replaced.

The battery low indicator was going for about 3 weeks in which time I did 4 dive trips totalling 172 dives before I took it in, but it was still running.

Like you I find it frustrating that there is no real battery percentage indication so I had a scratch around the Suunto DM5 desktop application to see if anymore useful data is being passed from the watch to the application but not being shown.

Going through at log and app files etc the only place I could so far find that made useful reference to a battery is in the dive log files stored by the application. On my windows PC I found them here: C:\Users\User\AppData\Roaming\Suunto\Suunto DM5\
with the latest set of logs C:\Users\User\AppData\Roaming\Suunto\Suunto DM5\
Each dive is stored in its own datestamp.sml file - which is just a standard XML file with a bunch of elements, attributes and data values. You can open the file in a text editor such as notepad to check its insides.

At the top there are a couple of config elements and attributes that you may ignore:

<?xml version="1.0" encoding="utf-8"?>
<sml SdkVersion="2.19.2" Modified="2012-09-22T10:39:51" xmlns:xsi="" xmlns:xsd="" xmlns="">

Then a <DeviceLog> element which encapsulates the lot and then the <Header> element with the data you are after. Below is data in the header element of the last dive I did before taking in the watch for the battery to be replaced:


As you can see there is an element in there called Battery with a value of 2.5 (<Battery>2.5</Battery>). I'm not 100% sure what the 2.5 signifies but as the D4i utilises a 3 Volt battery my assumption is that the indication of the battery voltage for that dive.

The log file directly after is what looks like the pressure test the company did after installing the battery:

       <Algorithm>Suunto Technical RGBM</Algorithm>

The battery element showed <Battery>3.2000000000000002</Battery> which to me indicates that a new battery has been installed and the voltage 3.2V

The log entry file directly after the one above is the first dive I made after I received it back and it's showing the battery element as <Battery>3</Battery>. The last log entry file in the folder is the last dive I made on 2018-05-05 and is showing the battery element as <Battery>2.8999999999999999</Battery> which leads me to the conclusion that the battery voltage dropped 0,1V in the 148 dives I made since battery replacement.

So... there may be other ways of checking the current battery status that I'm unaware of but lacking this my recommendation is to do a dive or dunk your watch in pool deeper than 1m to simulate a dive, then connect your watch to the DM5 app, get hold of the last log entry file and check the battery status. If your are planning a trip and the battery is below 2.7V, get it replaced. Anything above 2.7V should give you enough juice for a extended trip. Alternatively if you watch is out of warranty then it may be worth taking a spare battery (CR2450) on you dive trip and if it does die replace the battery yourself. There are quite a few articles and youtube vids online detailing the process.
Last edited:


May 17, 2018
Thanks for the detailed response! Mine hasn't showed the low battery warning yet, but I was wondering if there was a way to check the level before it got that low.


Well-Known Member
Aug 26, 2015
@landshark. Thanks a lot buddy! That was a excellent answer!

I’m on OSX, but I’m gonna do some digging myself to see what I can find. I don’t have the cable yet for hooking it up to the computer so I guess that’s gonna be my first stop. :)

Anyways, this time I’m gonna go for a change. Better safe than sorry, right!? It’s like 450Sek ($50) to do the change which is cheaper than I thought considering the USB cable costing like $90 (wtf is that about btw!?).

Rob Bonaire

New Member
Dec 22, 2020
You can check it on your Suunto D4i and D6i via <General settings> <Version>.
There you will see "BAtt" with a number. For instance 3.2 directly after installing a new battery.


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Jan 3, 2016
You can check it on your Suunto D4i and D6i via <General settings> <Version>.
There you will see "BAtt" with a number. For instance 3.2 directly after installing a new battery.
unfortunately my old firmware 1.0.2. does not support Battery status. But thanks to landshark se I can recall the dive data via Suunto DM5 Software - export any dive to .sml. Open with a text editor and in the header there is the battery status. 3.2 is full (reads: 3.199999999); voltage drops within a few dives to 3.0, then stays at 2,9V for a long time. At least this was the readout I have achieved. A half year and 500 freedives later it still shows 2,9V and the last dives even happened in very cold water. - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing


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