The Ultimate Charger
Sometimes the most important issue is the lifetime of the batteries or the total lifetime cost of the system. In this case PowerStream is in a good position to offer the ultimate charger because of our wide experience in microprocessor controlled battery chargers and power supplies. Specs for the ultimate charger are:
1. Soft start. If the temperature is above 40 degrees C or below zero degrees C start with a C/10 charge. If the discharged battery voltage is less than 1.0 Volts/cell start with a C/10 charge. If the discharged battery voltage is above 1.29 V/cell start with a C/10 charge.
2. Option: if the discharged battery voltage is above 1.0 Volts/cell, discharge the battery to 1.0 V/cell then proceed to rapid charge.
3. Rapid charge at 1 C until the temperature reaches 45 degrees C, or the dT/dt indicates full charge.
4. After terminating the fast charge, slow charge at C/10 for 4 hours to ensure a full charge.
5. If the voltage climbs to 1.78 V/cell without otherwise terminating, terminate.
6. If the time on fast charge exceeds 1.5 hours without otherwise terminating, terminate the fast charge.
7. If the battery never reaches a condition where the fast charge starts time out the slow charge after 15 hours.
8. Fuel gauge, communication to the device being powered, LED indicators all possible.
Custom design and manufacture of state-of-the-art battery chargers, UPS, and power supplies for OEMs in a hurry!
Above provided for entertainment porpoises only. BunsenLabs accepts no responsibility for personal injury, property damage, or the heat death of the universe.
entertainment porpoises only.
The thing is, the original NiMh cells used in 1993-4 were typically rated around 900mA. The PowerBook will not work well with 2000 or 2500mA cells, anyway, as it seems not to know quite how to charge them. We have this behaviour in 540c recelling attempts too.
Higher capacity cells will take a good charge, but as far as I can determine, they will not take a full charge. Thus you will typically only get the battery life (2.5 hrs or whatever) originally projected for a Duo battery from a recelled unit; you will not get 3 times the battery life originally projected (7.5 hrs. or whatever). It seems to me that the charging circuitry is geared to lower capacity cells. Because of the memory effect in NiMh technology, this then has a degrading impact on the cells. I have had several batteries in which this happened.
Bunsen wrote:It's worth saving the removed 4/5A cells and testing them individually, if you can.
Mk.558 wrote:(get the dimensions first)
Existing width: 2 x 17mm + 49mm = 83mm
Existing length: 2 x 49mm = 98mm
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