Updated 20-6-2004
From my own limited experience, the batteries fitted to the "Solution"
type computers last no more than two years, after which you can expect
to see the Low Battery Warning symbol appear as shown right (or if
you're unlucky, the display will begin flashing during the best dive of
the season!).
If my memory's correct, on the last occasion I had a battery replaced
by Suunto's agents in the U.K. (then Blandford Sub Aqua), I was charged
the exorbitant fee of £28 or thereabouts. Given that an equivalent
battery could be purchased at that time for about £3.00, I queried the
amount and was informed that the "extra" cost was incurred because they
"performed a pressure test and a re-calibration".
O.K. a pressure test I can accept and the peace of mind that it'd be
tweaked to super accuracy convinced me that it just might be worth it -
but on a later occasion when I returned the unit to Blandford because
it was inaccurate I was told they couldn't be recalibrated, a
replacement (for a price similar to what they are sold at Dive Shows)
was the only option! Someone at Blandford it seems, had been telling
porkies. I therefore decided on two things; first, in future I'd replace
the battery myself and second, I'd avoid Blandford and the products for
which they were main agents like the plague.
Furthermore, on a recent trip to my local diveshop (2004) I saw that they were selling D.I.Y. battery replacement kits comprising O-ring, battery and plastic cover for the princely (or should that be pricely?) sum of just under £16; a good bit better than having it done "professionally" but still quite a bit OTT.
So, if like me you don't enjoy being "ripped off" and you want to save a few pounds, read on.
First, don't be tempted to remove the old battery before you've acquired a replacement. I've had reports that some computers might have developed problems when the battery has been left out for some time (progam corruption - an error code is displayed after the display wakes up), I don't know how true this is, but if they use volatile RAM to store the program it's not impossible; even a newly "flattened" battery will hold enough charge to support volatile RAM for several months - provided you don't try to use it and fully drain the battery.
The original fitted to mine was a Saft LS-14250. This is a 1/2AA, 3.6V Lithium Thionyl Chloride cell. (Note that 3V Lithium Manganese types sold for cameras are NOT the same AND WILL NOT WORK.)
Alternative sources of batteries (prices as of spring 2000):
| Supplier | Manufacturer and capacity | Stock no. | Cost |
| Farnell | Sonnenschein 1 A.Hr | 206-520 | £4.25 |
RS |
Saft 0.95 A.Hr | 596-589 | £4.27 |
CPC* |
Sonnenschein 1 A.Hr | BT00098 | £5.00 |
CPC* |
Sonnenschein 1 A.Hr | BT0009866 | £5.00 |
CPC |
Saft 1 A.Hr | BT000517 | £4.12 |
| Radio Shack (US) | Tadiran TL2150 0.95 A.Hr | 23-026 |
* For some reason, the stock number for this battery on the website is different to that in the catalogue.
In addition to the above suppliers, there's a company fairly local to
me who specialise in supplying cells and batteries, I haven't used them
myself but it might be worthwhile contacting them as neither RS nor
Farnell are particularly cheap and Maplin, who used to stock them, no
longer do so (confirming my belief that they'e the most unreliable
supplier I've ever had dealings with).
They are:
Cell Pack Solutions Ltd
Unit 202 Tedco Business Works
South Shields NE33 1RF
Tel. 0191 427 4577 Fax 0191 427 4606
Another supplier (who sell the 1/2 AA Sonnenschein for £5.50 incl UK p&p):
WatchBattery (UK)
Hyde View House, The Hyde
Purton, Wilts SN5 4EA.
And yet one more supplier ....The Small Battery Co.
Also required is some silicone grease, a small cross-head screwdriver and a small terminal driver.
I don't know about the other types of Suunto, but on the standard Solution and 'Alpha versions, the electronics are sealed within a gel filled compartment. The battery holder is embedded in this and has its own lid and seal. This means that if you should be unfortunate enough to incorrectly reseal the unit, water will only get into the battery chamber, the electronics will be unaffected and provided you can quickly disassemble it and rinse any salt water out of the battery chamber and dry it, there should be little danger of permanent damage.
It isn't necessary to remove the strap, however the protective lens (if
fitted) should be removed to prevent the unit rocking about while
you're busy. It's also advisable to cover the contacts with insulating
tape to prevent the unit being turned on whilst you're handling it.
Remove the four self tapping screws (hold the back in place until
they're all out), then lift the back away to reveal the battery
compartment.
The picture above shows the back removed with the battery cover still in place and the new battery and O-ring ready for fitting.
Now gently prise the clear plastic cover away from the battery holder
- it may be a little tight but it's only held in by friction and, if
you've been lax in post-dive rinsing, salt deposits.
This picture shows the removed battery cover with the O-ring still in place and the old battery within its chamber prior to replacement.
The retail D.I.Y. kits supply new both a new cover and O-ring but I can't see why the cover needs changing provided you're carefull not to scratch it while prising it out; likewise, the O-ring should be O.K. unless you damage it.
Carefully remove the O-ring taking care not to scratch the sealing
faces of the cover and/or compartment; if it appears to be in good
condition you can clean it with warm soapy water, thoroughly rinse and
dry it then re-lubricate it with a SMALL amount of silicone grease.
Likewise clean and lightly lubricate the lip of the battery cover.
The correct size and hardness specification for a new
O-ring is: 26.7mm x 1.78mm 70sha. I've been told that these can be
obtained individually from dive shops although I havn't tried my local
shop yet, the Suunto manual gives the part number as K5508, which
implies that they'll sell them to the general public. Alternatively, if
you have access to a supplier of O-rings this is a size "023".
The old battery can now be removed BUT be careful to note the polarity
beforehand, not all Solutions have a convenient label inside the
compartment as shown in the picture on the right.
After cleaning the rim of the compartment and lubricating the seal
area (be careful not to get grease onto the battery contacts), fit the
new battery (despite being labelled as a 1/2AA size, the body of the
original Saft battery was physically smaller than the new ones I've
used, however they do fit).
Fit the O-ring to the cover and carefully re-fit it to the battery holder. 
It'll
probably try to "pop" off while the case is being re-assembled, but it
can be held in position with a terminal screwdriver located through one
of the holes in the strap that coincides with the battery inspection
opening as shown on the left.
Hold the back in place while replacing ALL the screws and GENTLY tighten them.
After fitting the new battery, it can be somewhat disconcerting to see that the battery warning indicator remains on after it's powered up for the first time - but don't panic, it'll extinguish after a short time.
And that's it, it's ready for use again. If you're in any doubt about the integrity of the seal or your workmanship, try to make your first dive in freshwater - then any leaks will be less likely to corrode the battery contacts - salt water and electricity do not mix!
Maplin's and CPC's on-line catalogues can be found at:
Contact: Dave Cordes.