QT designed instrumentation -IVVI rack page- -batteries-



Supply
The IVVI-rack/IVVIDAC-rack is operated with 2 battery units , each unit containing two 6V rechargeable batteries (capacity:12AH).
One battery-unit supplies the BNC-outside world-electronics, the other unit supplies the LEMO-sample-side-electronics. Expected operation time for a battery unit is >60 hours. IVVIDAC racks have two connectors for each supply, enabling uninterupted batterychange and so continuous measuring for long periods.

The IVVI-DAC rack can optionally be equiped with a third input, powering (part of) the DAC-module (if not: standard powered via "lemo-side"). In case of a DAC-module with 16 DACs, two groups of 8 can be split into "lemo-side" powered and dedicated DAC-only battery unit.

The SMS-system (used on fridge) has one main battery (double connector) A switch allows the user to choose for a second DAC-only battery. Expexted operation time for the main batt. is 24 hours, DAC-batt >100 hours.
BATTERY UNIT:

Metal battery-enclosures are used in combination with shielded cables. These enclosures are connected to sample-ground and thus mounting them should be done free of connections to mains ground. The fuses on the battery units prevent excessive currents (>6A) in case of short circuit. Both battery unit connectors & switches are found on the back of the rack.
picture of battery-cable
drawing of battery-connector pin-out
measured discharge curve (@200mA), Voltage<>capacity
CHARGER:
Commercial battery-chargers are used, which can remain connected to a battery unit even if it is fully charged (indication on charger). Do not try to use a power supply or other charging method as this could cause degrading or overheating of the batteries. Charging time will be <24 hours in normal conditions, but for a to-deep discharged battery (<4V) the charger starts some re-animation routine, called forming, taking another 10..20 hours. When the battery-unit is charged the charger
automatically switches to a low current so it can be left connected for long time.
BATTERY TESTER:
For testing standard, triple and regulated(via charge connector) 6V battery-units. Gives a DUAL LED indication 100-75-50-25% charge for both batteries in one unit, both indicators should light. Can be connected while measuring (produces no clock signals) in 2 ways:
1-Most batteries have a second connector to which it can be connected.
2-The tester has a throughput-connector to be placed in the supply-chain.
current drawn by the tester is only 1mA (=10.000 hrs battery life)
The tester can also be used to check the charger, plug the charger cable into the panelsocket of the tester, both indicators should read 100%
O1: Battery-read-out on IVVIDAC-m rack:
This (fixed) module shows permanently batterystatus for max 3 battery-units (=6 batteries).
Each battery-unit has a dual 3-LED indicator indicating the charge of the two batteries by a green/yellow/red LED for: 100-60% 60-20% 20-0% remaining charge.
splitterbox to get 2 batt.connectors :
When there is only 1 batteryconnector on a unit this makes it 2
plug in a fresh batt before taking out the old one to have uninteruptable operation. Example: SMS dacs
WARNING:
After leaving the batterybox in water (condensed from Cryostat)
This is NOT the inside battery-acid leaking out but the outside-box being oxidised.