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- From: tom@fokus.gmd.de (Tom Pfeifer)
- Newsgroups: misc.consumers,misc.consumers.house,misc.kids
- Subject: Re: Rechargable Battery Source Needed (and a Query)
- Message-ID: <1993Jan5.122203.21950@fokus.gmd.de>
- Date: 5 Jan 93 12:22:03 GMT
- References: <1993Jan4.150614.6635@kodak.kodak.com>
- Sender: news@fokus.gmd.de (News system)
- Distribution: na
- Organization: GMD-FOKUS, Hardenbergplatz 2, 1000 Berlin 12, Germany
- Lines: 34
-
- In article <1993Jan4.150614.6635@kodak.kodak.com>, marulli@kodak.kodak.com (Dave x71244/RDCS/2-205-KO) writes:
- |>
- |> Also, does anyone have hints about uses of NiCads? For example, one toy
- |> will not run on known good rechargables. ... the NiCads are .25V lower than standard
- |> batteries and the truck must need the full voltage (4x1.5V) I have a problem
- |> with this because the truck simply slows down with weak standard batteries
- |> but still starts up.
- |> What about mixing NiCads and standard? Rumor has it that I will weaken
- |> both types of batteries very rapidly. True?
-
- Rechargable NiCa batteries have a voltage of 1.2 V, non-rechargable cells 1.5 V.
- The more cells a device needs, the more important is this difference.
-
- When a cell is weak it is more important that its internal resistance is
- increasing than the slightly falling voltage. The result is that you can draw
- less current out of it.
-
- The internal resistance is also the reason you should never mix different types
- of cells and never mix strong and weak cells. To avoid a lecture about electricity
- here just imagine the stronger cells try to charge the weaker ones.
-
- Every type of cell looses energy by discharging itself, NiCa cells most quickly
- (days), followed by zink/coal standard cells (months) and alkaline cells (years).
- Alkaline cells contain more energy per volume then zink/coal cells, but are more
- expensive. NiCa cells are most expensive.
-
- Advice: Use only alkaline cells for devices which need low power for a long time
- (clocks, tv remote controls). Use rechargable NiCa cells for devices which need
- high power for a short time, which work with the lower voltage, and are used
- often enough to make the investment (cells+charger) worthwhile. Use freshly
- charged ones to get the whole capacity. Use alkaline or zink/coal cells for
- devices which need high power when using NiCa fails for one of the reasons.
-
- Tom
-