Doug Kerr
Forum Pro
Many of us use AA-size rechargeable Ni-MH "batteries" (properly, "cells) to power our flash units and perhaps other accessory apparatus.
Thomas Distributing now offers a remarkable battery charger/conditioner/capacity tester for these batteries, the La Crosse BC-900.
This unit will accommodate up to 4 AA batteries (or AAA batteries, as a matter of fact), and has a separate charging and management circuit for each "compartment". Each compartment has an individual display panel, which indicates the present operating mode and phase, and whose numeric display can be changed with the Display button to indicate any of four parameters: battery voltage, present charge (or discharge) current, elapsed time of this phase, and total mA-hr quantity for the completed discharge phase if applicable (see discussion of operating modes and cycles below).
For each battery chamber, any of the following modes may be invoked (different modes for different chambers, if you wish):
CHARGE - Here the battery is charged, and once charged, is maintained charged by a "trickle charge". This is the default mode (applicable if the user does not promptly select another mode when a battery is inserted in a chamber.)
DISCHARGE - Here the battery is discharged and then automatically recharged. (It is said to be desirable to do this for Ni-MH batteries perhaps every ten charging cycles.)
REFRESH - Her the battery is discharged, the charged fully, then discharged, then charged fully, until there is no significant further increase in apparent "capacity" (determined by the total mA-hr quantity delivered by each discharge other than the first). I believe that no more than 20 cycles will be conducted.
TEST - Here the battery is fully charged, then discharged, then fully charged again. The "capacity" (as indicated by the total mA-hr quantity delivered during discharge) is automatically displayed at the completion of the process (the display alternates between "Full" and the mA-hr quantity).
In the DISCHARGE and REFRESH modes, the total mA-hr quantity delivered can be read by operating the display button, any time after completion of the discharge phase.
The charging current can be set to any of the following (separately for each chamber if you wish): 200 mA, 500 mA, 700 mA, or 1000 Ma. The default is 200 mA. If only one battery is in place, or two batteries if you place them in chambers 1 and 4, charging currents of 1500 mA or 1800 mA can be used.
In modes involving charging and discharging, the discharge current is always half the set charging current. In these modes, the charging current can be set to 200 mA, 500 mA, 700 mA, and 1000 mA.
The operating mode and the display mode can be changed for each compartment separately, or for all four chambers together.
The unit is furnished with a "direct plugin" power brick suitable for use on a supply of 100-240 V, 50/60 Hz.
The unit is supplied with a nice nylon carrying case with a removable shoulder strap, four adapters to allow the use of AA batteries in D-cell apparatus, four adapters to allow the use of AA batteries in C-cell apparatus, a set of four AA size Ni-MH batteries (rated at 2000 mA-hr) and a set of four AAA size Ni-MH batteries (rated at 700 mA-hr).
The current price for the entire package from Thomas Distributing is $42.97 plus shipping.
Here is a link:
http://www.thomas-distributing.com/la_crosse_bc-900_battery_charger.php
The manual for the unit is available as a PDF file via a link on that page.
Best regards,
Doug
Visit The Pumpkin, a library of my technical articles on photography, optics, and other topics:
http://doug.kerr.home.att.net/pumpkin
'Make everything as simple as possible, but no simpler.'
Thomas Distributing now offers a remarkable battery charger/conditioner/capacity tester for these batteries, the La Crosse BC-900.
This unit will accommodate up to 4 AA batteries (or AAA batteries, as a matter of fact), and has a separate charging and management circuit for each "compartment". Each compartment has an individual display panel, which indicates the present operating mode and phase, and whose numeric display can be changed with the Display button to indicate any of four parameters: battery voltage, present charge (or discharge) current, elapsed time of this phase, and total mA-hr quantity for the completed discharge phase if applicable (see discussion of operating modes and cycles below).
For each battery chamber, any of the following modes may be invoked (different modes for different chambers, if you wish):
CHARGE - Here the battery is charged, and once charged, is maintained charged by a "trickle charge". This is the default mode (applicable if the user does not promptly select another mode when a battery is inserted in a chamber.)
DISCHARGE - Here the battery is discharged and then automatically recharged. (It is said to be desirable to do this for Ni-MH batteries perhaps every ten charging cycles.)
REFRESH - Her the battery is discharged, the charged fully, then discharged, then charged fully, until there is no significant further increase in apparent "capacity" (determined by the total mA-hr quantity delivered by each discharge other than the first). I believe that no more than 20 cycles will be conducted.
TEST - Here the battery is fully charged, then discharged, then fully charged again. The "capacity" (as indicated by the total mA-hr quantity delivered during discharge) is automatically displayed at the completion of the process (the display alternates between "Full" and the mA-hr quantity).
In the DISCHARGE and REFRESH modes, the total mA-hr quantity delivered can be read by operating the display button, any time after completion of the discharge phase.
The charging current can be set to any of the following (separately for each chamber if you wish): 200 mA, 500 mA, 700 mA, or 1000 Ma. The default is 200 mA. If only one battery is in place, or two batteries if you place them in chambers 1 and 4, charging currents of 1500 mA or 1800 mA can be used.
In modes involving charging and discharging, the discharge current is always half the set charging current. In these modes, the charging current can be set to 200 mA, 500 mA, 700 mA, and 1000 mA.
The operating mode and the display mode can be changed for each compartment separately, or for all four chambers together.
The unit is furnished with a "direct plugin" power brick suitable for use on a supply of 100-240 V, 50/60 Hz.
The unit is supplied with a nice nylon carrying case with a removable shoulder strap, four adapters to allow the use of AA batteries in D-cell apparatus, four adapters to allow the use of AA batteries in C-cell apparatus, a set of four AA size Ni-MH batteries (rated at 2000 mA-hr) and a set of four AAA size Ni-MH batteries (rated at 700 mA-hr).
The current price for the entire package from Thomas Distributing is $42.97 plus shipping.
Here is a link:
http://www.thomas-distributing.com/la_crosse_bc-900_battery_charger.php
The manual for the unit is available as a PDF file via a link on that page.
Best regards,
Doug
Visit The Pumpkin, a library of my technical articles on photography, optics, and other topics:
http://doug.kerr.home.att.net/pumpkin
'Make everything as simple as possible, but no simpler.'
