Proper terminology when speaking of battery charging.
03-28-2009, 07:45 AM
#1
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Proper terminology when speaking of battery charging.
While this might be classified as "Nit Picking" it can effect whether or not you get a correct answer to a problem related to battery charging. In general, there are three descriptive charging rates; "trickle charge", "slow charge" and "fast charge". To often people speak of trickle charging when they really intend to mean "slow charge". Trickle charge is defined as just that amount of current to overcome the self discharge rate, usually in the low milliamp range and varies greatly with age of battery, temperature and internal construction and not very pertinent to most RC battery discussions. Slow charge is typically the 0.1C charge rate but can be something else. Fast charge is usually defined as "What is the fastest a cell can be charged without excessive damage" and is often about a 1C rate although some designs can be rated higher. It will usually help you to get a more correct answer if you use the proper terminology.
03-28-2009, 08:24 AM
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RE: Proper terminology when speaking of battery charging.
ORIGINAL: Rodney
While this might be classified as "Nit Picking" it can effect whether or not you get a correct answer to a problem related to battery charging. In general, there are three descriptive charging rates; "trickle charge", "slow charge" and "fast charge". To often people speak of trickle charging when they really intend to mean "slow charge". Trickle charge is defined as just that amount of current to overcome the self discharge rate, usually in the low milliamp range and varies greatly with age of battery, temperature and internal construction and not very pertinent to most RC battery discussions. Slow charge is typically the 0.1C charge rate but can be something else. Fast charge is usually defined as "What is the fastest a cell can be charged without excessive damage" and is often about a 1C rate although some designs can be rated higher. It will usually help you to get a more correct answer if you use the proper terminology.
While this might be classified as "Nit Picking" it can effect whether or not you get a correct answer to a problem related to battery charging. In general, there are three descriptive charging rates; "trickle charge", "slow charge" and "fast charge". To often people speak of trickle charging when they really intend to mean "slow charge". Trickle charge is defined as just that amount of current to overcome the self discharge rate, usually in the low milliamp range and varies greatly with age of battery, temperature and internal construction and not very pertinent to most RC battery discussions. Slow charge is typically the 0.1C charge rate but can be something else. Fast charge is usually defined as "What is the fastest a cell can be charged without excessive damage" and is often about a 1C rate although some designs can be rated higher. It will usually help you to get a more correct answer if you use the proper terminology.
Slow charge does not usually require any termination of the charge because the heat generated is not sufficient to significantly shorten the life of the pack although if left to continue indefinitely it can cause some deterioration in performance (voltage depression).
Then there is quick charge, this is where the pack can be fully charged in 3 to 5 hours. On smaller packs termination may not be required for the reason stated above. Larger packs on the other hand can be seriously compromised if there is no termination method for quick charge (time, temperature or voltage peak)
Fast charge on the other hand must always have some termination mode, usually some form of voltage profile detection and in some cases a temperature back up.
A sub set of fast charge is dump time charge where the battery is first completely discharged and then charged for a fixed time depending on the charge rate and rated capacity of the battery. This technique has been employed by the car guys and smaller electric flight, but at best is risky and worse case can destroy the pack.
