Rollei 35 / 35S / 35T: Batterie wechseln (PX625 → Typ 675 mit Adapter)

Rollei 35 / 35S / 35T: Changing the battery (PX625 → Type 675 with adapter)

video thumbnail for 'How to change Battery on a Rollei 35 35 T and 35 S + use a 675 Zinc Air to PX625 Adapter' Many Rollei 35 owners eventually face the same question: Which battery belongs in the small camera – and how do you change it properly? The original PX625 mercury cells are no longer available. Fortunately, the old batteries can be reliably replaced: with type 675 (hearing aid batteries) together with a small rubber ring adapter. In this guide, I will show you step by step how to do this, what pitfalls there are, and how to get the light meter running reliably again.

Why an adapter and why type 675?

The Rollei 35 models were originally designed for PX625 mercury batteries. These had a very constant voltage over their lifespan – an advantage for analogue light meters. Today, mercury cells are banned. Hearing aid batteries of type 675 (mostly zinc-air) offer a similar voltage and discharge curve and are therefore the best modern alternative. Problem: Type 675 cells are somewhat smaller than the old cells. Therefore, you need either a simple rubber ring adapter (ideal for Rollei 35) or a specially designed adapter for other camera models. Ecopack 675 battery pack with O-ring adapter and Rollei 35S on work surface

What you need

  • Type 675 hearing aid battery (zinc-air is ideal)
  • Rubber ring adapter for PX625/type 675 (small O-ring)
  • 10-cent coin (or a suitable tool) to unscrew the battery cap
  • Q-tip / cotton swab and contact cleaner
  • Small screwdriver (for gently roughening / straightening the contacts)

Step-by-step: Changing the battery

  1. Open the camera
Open the back of the Rollei 35 and slide out the film holder – the battery is not in the film area itself, but in a separate, screwed-in battery chamber. Opened Rollei 35 camera, finger pointing at battery chamber, type 675 batteries and rubber ring in the background
  1. Remove the battery cap
The small cap of the battery chamber capsule is unscrewed counterclockwise. You can use a 10-cent coin or a small tool. The cap falls out, then the chamber is open. Hands unscrewing the battery cap of an opened Rollei 35, battery compartment visible
  1. Remove old battery & check contacts
Take out the old cell. Look at the two contacts: one fixed, one spring-loaded. For used cameras, it is advisable to clean the contacts. removed battery next to opened Rollei 35 battery chamber, contacts clearly visible
  1. Contact cleaning
If the contacts are oxidized or dirty, clean them carefully: lightly scrape with a screwdriver, apply some contact cleaner on a cotton swab. Slightly spread the spring contacts so they later exert firm pressure on the battery. Screwdriver cleaning spring contact in the battery chamber of the Rollei 35
  1. Adjust spring contact
Modern replacement batteries are often a bit thinner. Bend the small spring slightly outward so it securely contacts the battery later. Spring contact in battery cap bent outward
  1. Prepare the battery
Insert the type 675 battery into the rubber ring adapter. Note: Zinc-air batteries react with air; they have small openings and sometimes need a few minutes to reach full power. Hand holding type 675 hearing aid battery and small rubber ring adapter over opened Rollei 35
  1. Insert correctly
Polarity is important: on the Rollei, the plus side of the battery points down (towards the camera base). Insert the battery with the rubber ring into the chamber, place the cap on, and screw it back on. battery with rubber ring next to open battery compartment, finger pointing at plus-minus marking
  1. Test
Close the camera and check the light meter. If necessary, check the contacts again or that the rubber ring is seated correctly. In my test, the light meter works immediately after insertion. Rollei 35S top, finger pointing at the light meter display window on the camera base

Useful tips & common questions

  • Do zinc-air batteries react immediately? Not always. They need air contact, so it can take a few minutes until they deliver full voltage. Some cells only provide full reading after a short time.
  • Can I cause damage? With the low voltage and capacity of the batteries, damage to the camera is very unlikely. Still: leaking old batteries can cause corrosion – remove old cells and clean the chamber.
  • Why not silver oxide or alkaline? Silver oxide has a different discharge curve; some camera light meters can measure incorrectly because of this. Zinc-air (type 675) comes closest to the old mercury curve.
  • How long do the batteries last? Usually several months to years, depending on use and model. Rollei light meters can discharge faster if constantly activated – covering or removing the battery during longer storage is advisable.

In brief

  • Rollei 35 / 35S / 35T: PX625 (mercury) is outdated and no longer available.
  • Use type 675 hearing aid batteries together with a small rubber ring adapter as a replacement.
  • Check and clean contacts, slightly bend spring, observe polarity (plus down).
  • Zinc-air batteries sometimes need air contact, so a few minutes until full power.
If you have questions or are unsure which battery or adapter fits your model best: write to us or search the shop for Rollei products. With that said — good light and much joy with your Rollei! Your team from Ausgeknipst
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