Campbell Scientific PVS4100/4120/4150 Portable Automatic Samplers - Manual (Page 34)

Section 3. Operation
3-4
3.3 Battery
3.3.1 Battery: Operating and Backup (optional)
CHARGING AND REVERSE POLARITY PROTECTION
The sampler will charge ONLY the factory installed internal battery. This
charging takes place continually as long as there is incoming line power.
Should the need arise to only charge the internal battery, as would be required
to store the sampler for an extended period of time, simply place the “ RUN /
OFF “ toggle switch in the OFF position, and leave the sampler power breaker
on. Twenty-four (24) hours should be sufficient to fully charge the battery.
The sampler is equipped with REVERSE POLARITY PROTECTION for
checking the connection of an external battery. When attaching an external
battery, be sure to check the reverse polarity indicator. If it is ON, reverse the
connections at the battery.
FIGURE 3-1. Battery Performance Curve