Replacement Si board batteries - Varta 500 rst (AA size)?

[bmwsport]

I've been looking for ages and I cannot seem to find anywhere to purchase a pair of replacement Si board batteries. They are for the early Si board with the AA size red Varta 500 rst batteries - not the latter smaller size sanyo type on the facelift cars.

Any ideas?

[Brianmoooore]

CPC-Farnell, part # BT04235

RS Components part # 377-7911

Both are tag ended, but the tags are different from the originals, so will need soldering in place with short wire links. Because of this, make sure you know which way around they fit before removing the old ones.