The manufacturer specifies a self-discharge without measurements of approx. 9.5 years. Continuous measurements reduce the service life. At 5 hours measurement interval this is 7.5 years, at 1 hour approx. 5.5 years and at 30 min. approx. 4 years. You can turn off the iButton and store it for several years and then use it again. The iButton Android apps can’t turn off the iButton yet, you could only set the measurement interval to about 260 hours i.e. 11 days, this will also get them towards 8 years of life. There are women who report such long lifetimes. Above all, these women switch off the iButton after ovulation detection, i.e. in the luteal phase, and only switch it on again in the new cycle. The iButton therefore does not require continuous measurements.

Yes, you can read out any suitable NFP iButton with USB Micro/C- adapter and the two Android apps iButton Assist and 1-Click iButtons. You can stop the iButton only with the known PC/MacOS programs OneWireViewer, PC programs AibA and fertility calendar EndoTherm Basal. A new Android iButton cycle app is planned to be developed in H1 2021. Sign up as a beta tester at NFP @myiButton.eu with the keywords Android app beta tester.

There were special iButtons, which were not suitable for Android apps. I guess these are no longer in use.

New iButton have an additional sealing.

Yes, until about Q2 /2021 first beta apps for iPhone and iPad should be created. You can sign up as a beta tester with the keywords iPhone beta tester by email to NfP @myibutton.eu.

Some women want to better secure the iButton in the vaginal canal, e.g. so that it does not unintentionally fall into the toilet when going to the toilet at night.

In this case, the iButton capsule loop can be tied around the inner ring of a cut open femidom ring.

In this way, the iButton with the cap ring sits securely in the vaginal canal and can be easily pulled out again.

The EndoTherm basal thermometer set simplifies the recording of fertile periods immensely. The temperature values are recorded qualitatively during the absolute resting phases during sleep very close to the true “basal temperature”. Thus is, to

1. during the fertility peak, the drop in temperature on one or two days can be reliably and unambiguously recorded and displayed, which has advantages for the time of conception, just as the

2. the subsequent rise in temperature over at least 4 days clearly shows when the infertile phase has actually begun and

3. it can be measured in the subsequent period whether the luteal phase has a sufficiently long high-temperature period of at least 10 days. If this is not the case, a longer luteal phase can be achieved, for example, by supplementary nutrition, and

4. if the high-temperature phase is longer than 18 days, it can be assumed with a high degree of certainty that pregnancy has occurred.

If pregnancy has occurred, the temperature should remain in the high temperature position for approximately 3 months.

Unfortunately my iButton doesn’t seem to work anymore, i.e. it can’t be read out and is not recognized by the device. The adapter is recognized, i.e. it is the iButton itself. e.g.” The type initializer for “java.lang.System” has caused an exception.” | iButton not connected”

How can we proceed with this?


Please do not worry!

Mostly it is because Microsoft Windows made a new deeper Windows update, so AiBA needs to be repaired or Microsoft Visual J#® or the 1-wire driver newly installed over it, after that AiBA should work again.

    1. 1-Wire Drivers from Maxim
    2. x86 for 32bit systems or x64 for 64bit systems from Microsoft Microsoft Visual J#® 2.0 Redistributable Package – Second Edition.
    3. Load Aiba package

(As described in the instructions in point 4).

If it still does not work:

    1. Could you send a screen shot with USB stick inserted and iButton started with onewireviewer.exe
    2. If that doesn’t work, a remote maintenance session can be offered

The third possibility is that the iButton’s battery is already dead, due to misuse, but this should not hopefully apply.

There are two types of measurements:

    1. Every 24h preferably in the absolute rest phase i.e. usually between 2 and 5 am, most users achieve good values. This setting is extremely battery saving, moreover if the sensor is only switched on during the fertile measurement phase and then stored in a cool place and switched off or
    2. A special time interval is selected in which continuously the sensor takes the temperature. This is recommended for irregular sleep cycles, such as shift work. The time intervals can be between 20 min. and 2 h, or can be chosen arbitrarily different. Depending on the software program, either the corresponding minutes or seconds must be entered. It is not possible for the sensor to measure automatically only at night and stop during the day. Practically, then the entire fertile period over, for example, 10-15 days every or every 2 hours the temperature is recorded and then evaluated at the end of the fertile phase, 4 days after the first detection of cervical mucus deterioration.  The lifetime of the sensor is about 100,000 measurements

The cervical mucus method is extremely important in general and especially for automated measurement in order to find the exact time for reading and evaluating the temperature readings. This time varies in the healthy natural cycle each time between a good +/- 5 – 6 days.  Cervix is a medical term for the lower part of the uterus opening into the vagina. Its outer opening is the external cervix. The cervix with the cervix changes during the menstrual cycle from hard, closed to soft, open and vice versa again.

According to the cervical mucus method, the changeable consistency of mucus is observed at the vaginal outlet in the evening or even during the day. The mucus flow increases during the fertile days and is thick, sticky and whitish-yellow in color. Around or shortly before ovulation, the cervical mucus is more fluid, egg white and threads can be drawn.

On a subsequent evening, a first deterioration may be noted. From this first evening, each day is counted up to 4. From the 4th morning, the temperature can be evaluated and read with an automated basal thermometer. Before that, no values need to be read if the strategy goal in the fertile days was to get as safe as possible into the infertile time and to get as accurate as possible confirmation of the day of change to the infertile time.

If, on the other hand, the strategy goal is to realize a desire for a child and the couple is also sure to determine that the temperature during the most fertile days, has actually lowered by about 0.2- 0.3 °C compared to previous 6 temperature values, it is quite possible to read out and evaluate earlier.

Generally for women, especially towards menopause, who do not measure temperature values but rely more on the consistency of the change in cervical mucus, it should be noted that from the 4th day of the first deterioration in cervical mucus quality, at least in the evening, 100% infertility should have occurred.

A higher and significantly more certain statement is possible if other fertility symptoms, such as palpation of the cervix or temperature are added, which is recommended.

The digital basal thermometer measures in increments of 0.0625 °C. Here, a single internal basal temperature value measured every 24 h during the rest period, e.g. between 3 and 5 o’clock at night, is often completely sufficient. This automatically recorded internal temperature value is often much less prone to error than a temperature value that must be measured manually exactly every morning during the wake-up process.

According to the practice book of the working group NFP Natural & Safe, family planning with Sensiplan, Triasverlag, 19th edition, 2015, p. 50 and p.51 digital basal thermometers with a measuring accuracy of +/- 0.1 °C can be used for the safe application of the symptothermal method based on the rules of the AG NFP and also the rules of INER.org (Institut für Natürliche Empfängnisregelung Prof. Dr. med. Rötzer (INER) e.V.). The digital basal thermometer should display at least two digits after the decimal point. For the evaluation, the further digits after the decimal point are evaluated up or down to one digit after the decimal point, recommends the practice book with Fig.23.

The EndoTherm basal basal thermometer meets these requirements and is therefore suitable. This has already been proven by long-time, enthusiastic users, some of whom have published their measurements. At this point, many thanks for all who contribute to the creation of body and fertility awareness.

Thus, a scientific discussion about the accuracy of the basal thermometer should be unnecessary and discussions about it clearly settled.