6.1 Optional Power Sources


It is required to use a 12 V battery, even if using an additional external power source.

STS Telemetry Systems require a 12V sealed lead-acid battery (not supplied by Solinst, see Section 5.4 for battery specifications), which has one connection to the Distribution Box. The life-time of the battery varies depending on the frequency of your Sample and Report Rates. The following are estimates based on a minimum power source using a 12V/12AHr battery, with four dataloggers connected to the System. With only one datalogger connected to the Distribution Box, battery life estimates will be approximately 10% longer.


Solinst recommends using a 28-30 AHr deep cycle battery.

The battery life estimates assume the Controller and Modem are NOT set to be “Always On”. If used for more frequent data collection, with both Controller and Modem “Always On”, the battery life will be less than 2 days (A larger 60 AHr battery would last about 6 days). Therefore, external power or a solar panel is required for continuous recharging of the battery.

Sample Rate

Report Rate

Battery Life

Every 15 Minutes Every 6 Hours 4 - 6 Months
Every 5 Minutes Every 12 Hours 5 - 7 Months
Every 15 Minutes Every 24 Hours 12 - 14 Months
Every 15 Minutes Every 7 Days 13 - 15 Months

Table 6-1 Battery Life Estimates Using a Minimum Power Source 12V/12AHr Battery



If you choose a Sample Rate less than 10 minutes and/or a Report Rate less than 30 minutes, “Always On” will be checked by default, as the entire System has to be active. “Always On” means you will be using Remote Station power continuously. Ensure you have sufficient power supply.

If you choose to set your System to "Always On" or it is defaulted to "Always On", a 12V battery will last less than 2 days, before recharging is required.

External power and charge accessories are available for the STS Remote Station. A solar power connector package is available from Solinst, to be used with a user supplied solar panel. The package includes an External Power Cable to attach to a user-supplied solar panel and a Regulator, to handle the current from the solar panel. (Figure 6-5 shows connection for the solar power connector package). An AC Power/ Battery Charger Assembly is also available from Solinst. The Assembly comes with a battery charger and cables for connection to the ‘ Regulator’ terminal on the Distribution Box and to an AC power source to provide current for battery charging (See Figure 6-2).

Figure 6-2 Battery Charger Assembly (North American #108848)

Figure 6-2
Battery Charger Assembly
(North American #108848)


Figure 6-3 Standard Remote Station Setup

Figure 6-3 Standard Remote Station Setup
(12V Battery not Supplied by Solinst)


Figure 6-3 shows the standard connection to the 12V sealed lead-acid battery. If you choose to use a larger battery, a larger cable is available from Solinst (#108981).


Figure 6-4 Solar Power Connector Package (#108988)

Figure 6-4
Solar Power Connector Package (#108988)


Figure 6-5 shows connections for a solar panel.



If using a solar panel, you must ensure output is a minimum of 13V open circuit, in order to effectively recharge the 12V battery.


Figure 6-5 Remote Station Setup with Connections for a Solar Panel

Figure 6-5
Remote Station Setup with Connections for a Solar Panel (12V Battery not Supplied by Solinst)


The Solar Panel Regulator supplied by Solinst must be connected to the Distribution Box. It is recommended that you select a solar panel without a regulator.


The solar panel is user-supplied. The panel must output a minimum of 13V open circuit in order to effectively re-charge the 12V battery. As a guideline, the solar panel should be at least 15 Watts. Higher wattage panels are also suitable, as a Regulator is supplied as part of the solar panel connector package provided by Solinst. The Regulator supplied must be used, even if the solar panel you are using has a built-in regulator. Therefore, when choosing a suitable solar panel, it is recommended to use one without a built-in regulator. Below are more guidelines for a proper solar panel:

Generator Connector:

Max V in = 35VDC
Max Current = 3A

Regulator Connector:

Max V in = 35VDC
Max Current = 3A

Max V out = 10-16VDC
Max Current = 3A

Battery Connector:

Max V in/out = 7-15VDC
Max Current = 3A

Modem Connector:

V Modem = Battery V in/out,
Max Current = 3A (5A fused)


To accommodate the External Power Cable through the enclosure, the second NPT plug on the base of the enclosure will need to be removed (using an Allen Key), and a weathertight fitting, supplied by Solinst, threaded in its place.