Campbell Scientific CR3000 Micrologger - Manual (Page 87)

Section 7. Installation
87
Sealed Rechargeable-Battery Safety
There are inherent hazards associated with the use of sealed rechargeable
batteries. Under normal operation, lead acid batteries generate small quantities of
hydrogen gas. This gaseous by-product is generally insignificant because the
hydrogen dissipates naturally before building-up to an explosive level (4%).
However, if the batteries are shorted or overcharged, hydrogen gas may be
generated at a rate sufficient to create a hazard. Campbell Scientific makes the
following recommendations:
• A CR3000 equipped with standard, sealed-rechargeable batteries should
NEVER be used in applications requiring INTRINSICALLY SAFE
equipment.
• A sealed, rechargeable battery should not be housed in a gas-tight enclosure.
Table 5. Sealed Rechargeable Battery and AC Transformer
Specifications
Feature Specification
Battery Type Sealed Rechargeable
Manufacturer Yuasa
Model Number Yuasa NP7-6
Campbell Scientific Part Number 8216
Float Life @ 25°C 3 years minimum
Capacity 7.0 Ampere-hours
Shelf Life, Full Charge 6 months
Charge Time (AC Source) 40 hr full charge, 20 hr 95% charge
Operating Temperature -15°C to 50°C charge
-20°C to 60°C discharge
AC Transformer:
Input 120 VAC, 60 Hz
Isolated Output 18 VAC 1.11 Amp