MPM
Member
Registered: Jun 2000
Location: Sunnyvale, CA
Posts: 216 |
I don't think so...
quote: Originally posted by phdarch
I did so on the advice of the Radio Shack guy, who said that the power capacity of the NiCads is slightly higher than NiMHs (confirmed on package).
I haven't see the Radio Shack NiCd package you refer too, but this is likely marketing hype. Batteries are rarely rated by "power capactiy". Instead they are rated by "energy efficiency". Here NiCds rate at 150 Watt-hours per liter (Wh/l) and 50 Watt-hours per kilogram (Wh/kg). And NiMHs rate at 225 Wh/l and 70 Wh/kg. So NiMHs cram more energy (Wh) into the same volume (l) and also cram more energy into the same weight (kg). NiMHs are better than NiCds.
For Visor (and Palm) users what really matters is battery life. This is rated by milliamp-hours (mAhr). For that, current technology NiCds have a 250mAhr capacity, while NiMH have a 700mAhr capacity (I just bought some GE/Sanyo ones at Fry's that were rated this high. And only $3 each!) So NiMH have 2.8 times the capacity, thus 2.8 times the battery life, of NiCds.
quote: Originally posted by phdarch
Oh yeah, one other factor in my purchase I forgot to mention is that the Handspring site expressly recommends against NiMH, saying their power output is too high and could damage the Visor...any comments on that?
I could not find this anywhere on Handspring's web site. All they say is to only use alkalines in the Visor.
It's BS anyway. The output voltage of NiCds is 1.2V nominal. The output voltage of NiMHs is 1.2V nominal. The same! And the current draw is whatever the Visor needs at the moment. The only time ANY battery, at the same voltage, will output too much power is if something fails in the Visor and it shorts out the battery. This usually results in heat and smoke, and of course, a dead Visor. But the failure was not caused by the batteries.
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