PE-1 Backup Battery

Thanks to Lois Stevens, I've got some pictures of what the backup battery inside a PE-1 looks like.







It looks like this is a rechargable NiCad battery made by SANYO, of the type that was used as a backup battery on computer motherboards in the early PC years (1980's). Unfortunately, NiCads need to be recharged from time to time to keep their function. Most PE-1 units that have sat on a shelf for years at a time are likely to have dead batteries inside them.

What does this mean for the average user? First, the backup battery is not required to store patterns on a pattern card. Each pattern card has its own little battery inside it (CR2016 in mine), and so as long as that battery is still working, you can read mylars and keep them on the card.

The backup battery allows you to turn off your knitting machine electronics (which power the PE-1) and retain the working files you are using. Without a working backup battery, you will need to reconstruct those working files if you interrupt your work. That may or may not be enough of a hassle that you want to replace your battery.

If you do want to replace it, it looks like it is fairly readily available. The number you are looking for is N-50SB3, which is 3 N-50SB cells in series with some wire lead connectors. A German supplier who ships through Amazon-UK states that this is no longer being made, but offers a different technology (Nickel metal-hydride, NiMH) as an alternative. Lois found this US source. So it looks like this is a part that is available. Note that these links are from Feb 2011, so you may need to do a current search if you are reading this at a later date. It also looks like these batteries come with the wire tabs ready to put into the circuit board, so it should be a fairly straightforward job for someone with the right tools and skills¹ to remove the old one and put in the new one.

My PE-1 is still almost new, and from what I can tell I will need to break a sticker to get into the unit. So I am not planning to replace the battery before I sell it.

¹ According to DH who is an electronics hobbyist, you need to use a soldering iron and solder that are designed for work on electronics. Electronics solder uses rosin flux; the solder used for stained glass and plumbing uses an acid flux that will damage the board. Also, larger soldering irons are too hot and will also damage circuit boards. So even if you have a soldering iron around for other purposes, you need to take care.