Total Cost Table for Japanese Submarine Main Batteries

wispywood2344, on May 29, 2021, kindly provided the above table and comments to the effect: 

These 17 submarines are:

- 1 The last sub of the Oyashio class Japanese Submarine (JS) Mochishio(SS15)

- +10 /The ten Lead-acid Battery (LABs) and AIP (LABs + AIP) Soryu Mk.1 subs (JS Soryu (SS16) to JS Shoryu(SS26) inclusive). Note there was never a sub designated "SS21" as "SS21" was a Lithium-ion Batteries (LIBs) Development Program which years later provided LIBs on the Soryu Mk.2s and the Taigei-class.

- +2 The two Soryu Mk.2s (JS Oryu and JS Toryu)

- +4 The first four hulls of the Taigei-class.

The list is based on documents downloaded from the Acquisition, Technology & Logistics Agency (ATLA)of Japan’s Ministry of Defense (MoD) or ATLA’s predecessor's website. But there were many documents and some of them have already been deleted. For this reason wispy has not included the URLs of the sources.

Anonymous commentedon June 2, 2021:

Usually, the price of purchased items decreases somewhat every year due to progress in returning their capital investment and work efficiency improvement and so on. If the MoD paid the same money every day, the Board of Audit (BoA) would ask the MoD for the reason. Not only batteries but also the price of the 12V25/25SB submarine diesels shows similar trends.

Then, the higher price of SLHs in JS Toryu compared to JS Taigei clearly suggests increased numbers battery cells (+ca.5% = +ca. 30SLHs) of SLHs in JS Taigei.
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Pete Comment

I agree with Anonymous’s explanation for the cost reduction and add.

Another way of saying costs reduce due to “progress in returning their capital investment and work efficiency improvement” is the MoD and Japanese Ministry of Finance (MoF)make a conscious accounting decision to attribute more of the new Main Battery development costs to the first submarine with that Main Battery fitout.

This conscious accounting decision is evident in the non-coincidental pattern of cost reduction, ie. the reductions above are almost the same (8.9% versus 8.7%).

“Work efficiency improvement” might apply to more efficient battery production and more efficient installation of those batteries in the submarines over time.

AND/OR

It could include a much wider range of adjustments in the submarine to accommodate a heavier Main Battery tonnage, including ballast and buoyancy changes within the sub.
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Oyashio-Soryu-Taigei TABLE as at June 3, 2021.