Electronics experts please help! - Mark X Tricorder repair/battery replacement

ReelClones

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I have a Starfleet R&D/ DStines Medical Tricorder which no longer holds a charge. The back of the Tricorder was glued in so had to be pried open in order to reach the batteries!

So far so good, but what greeted me inside is a little beyond my electronics level! There are two rechargeable batteries which are normal, but it also has two metal rectangles that are wired in. I see no markings on them. Are they a type of battery? Anyone able to help me out with identifying a suitable replacement of all this so I can get the Mark X up and running again?!

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My first thought was that it was a stripped Type J battery; however, they are not rechargeable. But looking further they have to be 4 rechargeable cells in series. The 2 AA-type would only give you 2.4V total, not enough to power the electronics. But Rayovac MM724 rechargeable batteries are NiMH based. So the two middle cells must also be NiMH. Very common during the time when DStines produced these tricorders. He could not have used 4 of the AA batteries since it would cause the back panel to bulge when closed. The existing two AA batteries can be pushed to the left and right of the circuit board; then another type of NiMH battery was used like a 9V. However, the battery would still have been too thick so they removed the outer metal jacket of the battery to make it thinner. In the end the whole thing is a mess and would eventually fail.

I would replace the entire power system with a regulated 3.7V 800mAh LiPo battery. It takes up very little room and would power all of the circuitry for several more years. It is also easy to replace when it eventually fails in 8-10 years. I did this with another DStines battery system about 3 years ago and it is still going strong today.
 
One other note: After looking at several DStines tricorders I have found that no two battery systems are the same. He used what worked. While the tricorders work quite well, the battery tech of the time guaranteed eventual failure. We have come a long way since then.
 
My first thought was that it was a stripped Type J battery; however, they are not rechargeable. But looking further they have to be 4 rechargeable cells in series. The 2 AA-type would only give you 2.4V total, not enough to power the electronics. But Rayovac MM724 rechargeable batteries are NiMH based. So the two middle cells must also be NiMH. Very common during the time when DStines produced these tricorders. He could not have used 4 of the AA batteries since it would cause the back panel to bulge when closed. The existing two AA batteries can be pushed to the left and right of the circuit board; then another type of NiMH battery was used like a 9V. However, the battery would still have been too thick so they removed the outer metal jacket of the battery to make it thinner. In the end the whole thing is a mess and would eventually fail.

I would replace the entire power system with a regulated 3.7V 800mAh LiPo battery. It takes up very little room and would power all of the circuitry for several more years. It is also easy to replace when it eventually fails in 8-10 years. I did this with another DStines battery system about 3 years ago and it is still going strong today.
Thanks for the info gmprops , would something like this work? :


The Tricorder had a charging port, which I presume is no longer suitable, so how would I go about wiring the new battery to be rechargeable within the tricorder itself? There's no charging plug on the battery so would I need some kind of charging board in there?
 
Thanks for the info gmprops , would something like this work? :


The Tricorder had a charging port, which I presume is no longer suitable, so how would I go about wiring the new battery to be rechargeable within the tricorder itself? There's no charging plug on the battery so would I need some kind of charging board in there?
Yes, that would work. For the circuitry that DStines used at that time the current was more important than the total voltage. You would need to verify that the LiPo battery has a built in voltage charge protection circuit (most do these days). Not sure what the charging port is on this one, but I always use a barrel connector charging port to prevent accidental shorting of the positive and negative leads.
 
Yes, that would work. For the circuitry that DStines used at that time the current was more important than the total voltage. You would need to verify that the LiPo battery has a built in voltage charge protection circuit (most do these days). Not sure what the charging port is on this one, but I always use a barrel connector charging port to prevent accidental shorting of the positive and negative leads.
It's some sort of jack plug. Do you think it needs to be changed?
 

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