Mares Smart Battery Replacement Kit
If you purchase the above, please measure and update this thread.
If you purchase the above, please measure and update this thread.
Dive computer battery and o-ring spec's
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John in GA
Registered
Oceanic Datamax Pro Battery Compartment O-ring
I tried a -141 O-ring today and it is a bit of a tight fit. The O-ring that was in the unit is very close to a 2.2 mm cross section. I had no luck finding any metric or AS/MS O-rings that matched what was in the unit. I contacted Oceanic and they told me that it was a 2.140 O-ring. This would be an AS586-140 D70, which is equivalent to a MS28775-140. Dimensions of 2-1/4 ID X 2-7/16 OD X 3/32 W. This a significantly lager cross section than what was in the unit but definitely seems reasonable based on my experience with the -141 this morning. I'll pick up a -140 and see how that fits.
John in GA
Registered
Oceanic Datamax Pro Battery Compartment O-ring
I picked up a couple of -140 O-rings yesterday afternoon. As with the -141, they are a stretch install and a tight fir in the O-ring groove in the back of the computer. As with the -141, I cannot tighten the ring that holds the battery compartment cover to the point where the witness marks line up. I end up about 80 degrees shy of lining up the witness marks.
The 3/32 cross section -140 O-ring is definitely larger than what was in my computer. The -140 measures about .100" CS (3/32 = .09375") and the removed O-ring measures about .083"
I specifications for the MS28775-140 list the CS as 0.100 INCHES MINIMUM AND 0.106 INCHES MAXIMUM. An AN568 has the CS listed as .103±.003. So it is the same as the MS28775.
The -140 is what Oceanic specified for this computer and I did find one online reference for this O-ring that also listed a -140. The -140 CS really seems to be more than ideal for this computer. It stand significantly proud of the back of the case when installed and the cover nut cannot be tightened enough to line up the witness marks. I suspect it will work but I suspect a 2.2 x 60 MM would be a better fit. 2.2 mm is .0866". The 2.2 mm O-rings do not seem to exist in a diameter that is suitable. A 2.4 x 59.6, which is readily available online, should be a slightly better fit than the -140. 2.4 mm is .0945", so about .006" less than the -140.
So a -140 is what Oceanic specifies. However, the battery compartment nut cannot be tightened enough to align the witness marks, even with a -140 O-ring that is at the bottom end of the cross section specifications at .100". I suspect a -140 will work but it does not seem like the ideal O-ring. It is possible that oceanic changed the specifications on this computer and that later variants have a different size groove for the O-ring. My computer was manufactured in January of 1997. If anyone has a computer with a later date of manufacturing, and likely the dual 2032 batteries, please let us know if the -140 fits better there.
So for now I will use the -140. Whenever I order some more metric O-rings I will get some of the 2.4x59.6's to try.
I hope this helps someone else with this computer.
John
I picked up a couple of -140 O-rings yesterday afternoon. As with the -141, they are a stretch install and a tight fir in the O-ring groove in the back of the computer. As with the -141, I cannot tighten the ring that holds the battery compartment cover to the point where the witness marks line up. I end up about 80 degrees shy of lining up the witness marks.
The 3/32 cross section -140 O-ring is definitely larger than what was in my computer. The -140 measures about .100" CS (3/32 = .09375") and the removed O-ring measures about .083"
I specifications for the MS28775-140 list the CS as 0.100 INCHES MINIMUM AND 0.106 INCHES MAXIMUM. An AN568 has the CS listed as .103±.003. So it is the same as the MS28775.
The -140 is what Oceanic specified for this computer and I did find one online reference for this O-ring that also listed a -140. The -140 CS really seems to be more than ideal for this computer. It stand significantly proud of the back of the case when installed and the cover nut cannot be tightened enough to line up the witness marks. I suspect it will work but I suspect a 2.2 x 60 MM would be a better fit. 2.2 mm is .0866". The 2.2 mm O-rings do not seem to exist in a diameter that is suitable. A 2.4 x 59.6, which is readily available online, should be a slightly better fit than the -140. 2.4 mm is .0945", so about .006" less than the -140.
So a -140 is what Oceanic specifies. However, the battery compartment nut cannot be tightened enough to align the witness marks, even with a -140 O-ring that is at the bottom end of the cross section specifications at .100". I suspect a -140 will work but it does not seem like the ideal O-ring. It is possible that oceanic changed the specifications on this computer and that later variants have a different size groove for the O-ring. My computer was manufactured in January of 1997. If anyone has a computer with a later date of manufacturing, and likely the dual 2032 batteries, please let us know if the -140 fits better there.
So for now I will use the -140. Whenever I order some more metric O-rings I will get some of the 2.4x59.6's to try.
I hope this helps someone else with this computer.
John
John in GA
Registered
Oceanic Pro Plus 3 Battery Compartment Screws
For those of you replacing the CR2 battery and -028 O-ring in a Pro Plus 3 (and probably PP2) replacement screws are aircraft part number MS51957-4. These can be purchased from Aircraft Spruce, or most aviation supply houses, for a few cents apiece. They likely have a -028 O-ring as well. The screws have a slightly larger head than the oceanic screws but they still fit in the battery door. They allow the screw driver to get a better bite so there is less chance of stripping the head. However, this also makes it easier to over tighten and possible twist the head off of the screw. These are tiny 2-56 screws, they only need to be snug, not tight.
No, I do not work for Aircraft Spruce. I just an fortunate to have a store near me.
John
For those of you replacing the CR2 battery and -028 O-ring in a Pro Plus 3 (and probably PP2) replacement screws are aircraft part number MS51957-4. These can be purchased from Aircraft Spruce, or most aviation supply houses, for a few cents apiece. They likely have a -028 O-ring as well. The screws have a slightly larger head than the oceanic screws but they still fit in the battery door. They allow the screw driver to get a better bite so there is less chance of stripping the head. However, this also makes it easier to over tighten and possible twist the head off of the screw. These are tiny 2-56 screws, they only need to be snug, not tight.
No, I do not work for Aircraft Spruce. I just an fortunate to have a store near me.
John
I'm looking for the size of the O ring for the Mares Quad.
Am told that it is the same size as the Puck (not puck pro)
Can anyone verify this? AND know the size?
Measurement of where the O ring sits
ID 1.132" 28.75mm
OD 1.213" 30.82mm
Thickness .049", 1.25mm
Actually calipers were all over the place on the thickness from 1.04mm to 1.27mm!!!
Am told that it is the same size as the Puck (not puck pro)
Can anyone verify this? AND know the size?
Measurement of where the O ring sits
ID 1.132" 28.75mm
OD 1.213" 30.82mm
Thickness .049", 1.25mm
Actually calipers were all over the place on the thickness from 1.04mm to 1.27mm!!!
..hmm, cannot find it in the cart and the sizes you've given don't match standard metric seals. Try measuring the O.D. of the gland the o-ring fits in (on the cap.)
My best guess judging from the battery size (CR2450) and comparing it to other computers that use the same size battery, I would say -026 ...but again, that is a WAG.
My best guess judging from the battery size (CR2450) and comparing it to other computers that use the same size battery, I would say -026 ...but again, that is a WAG.
My understanding is Mares uses a properitarty size. Not surprised.
DiveGusto
Contributor
I was rebuilding a lot more items but not as much any more. I have a lot of O-rings available if people want to buy a few plus postage. Just replaced my computer o-ring. They are stored in a closet no light and kept cool. Located in Florida
All are Viton Duro 90
All are Viton Duro 90
Attachments
Re Shearwater computers-thank you to @DiveGearExpress for this link:
www.divegearexpress.com
Replacement O-Rings for Shearwater
Replacement O-Rings for Shearwater Research brand products.
www.divegearexpress.com
Thank you @DiveGusto , that may come in handy. V90 o-rings are good for many uses. Could I suggest you place that offer in the regular DIY forum as it's liable to get lost in a "computer battery" thread?
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