Batteries
How long do they last, and which one is best to use?
Energy efficient?
The differences between movements from different makers are significant. Some are pleasantly economical, others not at all. We also see differences between movements themselves. Age, service record, and maintenance received all influence the energy they require to move the hands.
Second hand
Some differences are easy to explain. A clock that needs a pulse every second is simply far less economical than a clock that only needs one every 60 seconds . So we can keep it short about seconds clocks: they are not suitable for running on batteries.
Pulse generator design goal
We developed the pulse generator with a high priority for energy efficiency. Consequently, the pulse generator itself consumes the least possible power! But who consumes power in the system: the clock and the pulse generator. Thanks to the efficient pulse generator, the balance of energy consumption has shifted almost entirely to the clock. After all, we (the pulse generator) cannot be much more efficient than the power demand of the clock in question.
Our goal was to let a clock with our pulse driver run on batteries for at least a year . In many cases this works well! And although we are pleased with the result of our design efforts, in practice 95% depends on the clock in question.
Below, we have outlined how the various brands can be categorized in terms of energy efficiency.
Very favorable
By far the most economical are the slave movements of the French Brillié (Electrique Brillié).
The same design can also be found in clocks by ATO and Charvet-Delorme.
Estimated battery life: 3 to 6 years (!)
These performance levels are achieved despite the 30-second pulse interval.
Average
Virtually all 12 and 24 volt pulse clocks fall into this category.
Siemens, Favag and Westerstrand: 1 to 3 years
TN, CTW, Bürk, , Moser Baer, Pragotron, Strela: 1 to 2 years.
Flip clock Bodet, TN: 1 year
Flip clock Pragotron: 1 year
Flip clock Solari Sifra, depending on the mechanical adjustment: 2 months to 1 year
Is the pulse voltage adjustable?
Some of these movements are adjustable for different voltages. In this case, it almost always pays to select the lowest possible voltage. For example, does a movement offer a choice between 12, 24, and 48 volt pulses? Then choose the 12V option.
Note: Our 12/24V pulse generator, intended for this type of clock, can only generate 12V or 24V pulses.
Unfavorable
The most power-hungry are the movements of
- Synchronome
- Gents
- Simplex / IBM
The two English clockmakers Gents and Synchronome have opted for a current-driven design for their slave clocks. Neither is particularly favorable in terms of power consumption. Synchronome performs slightly worse than Gents. Expected lifespan of a set of batteries for Synchronome: 1 to 2 months. A Gents can last 2 months to 1 year on batteries, depending on the movement.
The movements of Simplex and IBM contain a tensioned spring, requiring more force, and therefore more current, during a pulse. Estimated battery set life: 2 to 4 months. For those who wish to examine the movement closely and fine-tune the mechanism, up to a year or more is also possible.
Double-sided
A double-sided slave clock, one with two dials, typically also has two movements. The two movements can be controlled jointly using a single pulse generator. With two movements connected, this unfortunately also means a doubling of power consumption! Consequently, a battery-powered double-sided clock is often, though not always, not very practical. Check the estimated lifespan above and divide the number by 2 for an indication of a double-sided clock from the same brand.
Every clock is unique, and they all differ slightly in energy consumption as well. Therefore, we cannot guarantee how long your clock will run on a set of batteries.
We would like to hear about your experiences.
- How long does your clock run on a set of batteries?
- And which batteries were used for this?
Tell us, so we can share this knowledge with others again via the website!
Make the most of it!
What definitely helps for the longest possible battery life:
- Good batteries (see below)
- Above all, do not use zinc-carbon batteries.
- A smooth-running and clean movement; a well-placed drop of oil sometimes works wonders!
- Good (copper) wiring from pulse generator to clock, with as few 'transitions' as possible, such as terminal blocks and connectors.
Batteries
PHOTO: Hardware.info
When using batteries in a clock , it is all about a long lifespan at a (very) low load and discharge. After all, the clock uses little power over a long period. This specific use case was not included in the Hardware.info battery test, for the understandable reason that it would probably take (far) too much time. The tests were carried out very well, though, and the results at the lowest load are the most valuable for our application.
Lithium
For an even longer battery life, you can invest in lithium batteries. With these, the runtime can theoretically be doubled again. More and more manufacturers include lithium AA batteries in their range, so they are increasingly easy to find.
Rechargeable
For long-term applications, such as in a clock, traditional rechargeable batteries are generally less suitable. They have the disadvantage of having a (much) higher self-discharge rate than alkaline batteries. As a result, they spontaneously lose as much as 40% to 50% of their capacity in a year. And this energy is then no longer available for the clock!