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Originally posted by OotB
Originally posted by OotB
Distinct advantages of today's NiMH batteries are: [INDENT] 30% more capacity over a standard NICAD.
Less prone to memory than the NICAD. Periodic exercise cycles need to be done less often.
Fewer toxic metals. The NiMH is currently labeled "environmentally friendly".
[/INDENT]Negative attributes of today's NiMH batteries are:[INDENT] Number of cycles: The NiMH is rated for only 500 charge/discharge cycles. Shallow rather than deep discharge cycles are preferred. The battery's longevity is directly related to the depth of discharge.
Fast charge: The NiMH generates considerably more heat during charge and requires a more complex algorithm for full-charge detection than the NICAD if temperature sensing is not available. (Most NiMH batteries are equipped with internal temperature sensing to assist full-charge detection). In addition, the NiMH cannot accept as fast a charge as the NICAD; its charge time is typically double that of the NICAD. The trickle charge must be controlled more carefully than on the NICAD.
Discharge current: The recommended discharge current of the NiMH is considerably less than that of the NICAD. For best results, manufacturers recommend a load current of 0.2C to 0.5C (one-fifth to one-half of the rated capacity, see 3.1 C-Rate). This shortcoming may not be critical if the required load current is low. For applications requiring high power or a pulsed load, such as on GSM digital cellular phones, portable transceivers and power tools, the more rugged NICAD is the recommended choice.
Self-discharge: Both NiMH and NICAD are affected by reasonably high self-discharge. The NICAD loses about 10% of its capacity within the first 24 hours, after which the self-discharge settles to about 10% per month. The self-discharge of the NiMH is one-and-a-half to two times higher than that of the NICAD. Selecting hydride materials that improve hydrogen bonding to reduce self-discharge typically also decrease the battery capacity.
Capacity: The NiMH delivers about 30% more capacity than a NICAD of the same size. The comparison is made with the standard, rather than new ultra-high capacity NICAD. Some ultra-high capacity NICAD cells provide a capacity level approaching that of the NiMH. (Ultra-high-capacity NICAD batteries cannot provide as high a load current as standard NICAD batteries. They are also less durable in terms of cycle-count but are longer lasting than NiMH batteries).
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) prima oplaadbaar te doen en stukken goedkoper.
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