In 2010 I had surprising problems with replacement BLM-1 batteries for my Olympus E-30. Since then I've been keeping records aimed at understanding battery problems. In December 2013, I replaced the E-30 with an Olympus OM-D E-M1, and the original records for the E-30 are now here. This page relates to the BLN-1 batteries for the E-M1.

There's a difference in the market between the BLM-1 and BLN-1: the Olympus battery charger for the BLN-1 only supports coded batteries, and many of the replacements on the market can't be charged with that charger. Instead, they're supplied with their own charger. I don't know if this raises any quality issues, but it seems reasonable to assume that the suppliers of the coded batteries have gone to more trouble, and so are less likely to cause problems. Based on this and my experience with the E-30, I have bought a set of three coded BLN-1 replacement batteries.

The batteries

My current batteries are

Number		Date		End date		Comment
1		3 December 2013				The original battery supplied with the E-M1.
2		17 December 2013		3 April 2022		One of the first set of three replacement batteries.
3		17 December 2013				One of the first set of three replacement batteries.
4		17 December 2013		15 July 2022		One of the first set of three replacement batteries.
5		27 July 2022		22 August 2022		Replacement for dying 1-3
6		26 August 2022				Replacement for dead 5