Most battery chargers allow you to select the bulk charge current from only a few options. The charging rate of an AGM battery is controlled by selecting the appropriate current setting in your charger. With larger-capacity AGM batteries, the maximum recommended charging current cannot be sourced by typical battery chargers, and the charger capacity will limit your currents. For a rough estimate of the max current in amps, divide the battery amp-hours by 4: a 60Ah battery takes 15A, a 100Ah battery 25A, and a 200Ah battery 50A. The maximum charging current depends on the battery size, and can be obtained using the formula above. This is the max rate recommended by most AGM battery manufacturers. The maximum current you should use to charge an AGM battery is, in most cases, the current that produces a 0.3C charging rate. The standard charging rate 0.1C to current conversion is very easy to remember: AGM charging current = battery amp-hours / 10. Fast charging a larger 100Ah AGM battery at 0.3C takes a current of 0.3C x 100Ah = 30A. Let us take a few application examples: Charging a typical 60Ah car battery at the normal charging rate of 0.1C takes a current of 0.1C x 60Ah = 6A. The charge current required for a given charging rate is calculated as follows:Ĭurrent = rate x battery capacity Current (A)īecause amperes are key to AGM charging practice, it is important that you can translate the C-rates into amperes and back. Like the charging rates, the currents are usually specified only for the bulk charge stage. Which charger setting to use to get a 0.1C or some other charging rate Advertisements.How powerful a charger you will need for your AGM battery. The ampere values are relevant in that they tell you: A current of 10A into a 100Ah truck battery means a rate of 0.1C, but for a 50Ah car battery, it’s 0.2C. How do rates and currents relate? Take it like this: the same charger amps produce different charging rates for different size batteries. Your charger, however, only knows currents in amperes (amps, A). Charging currentsĬharging rate in C-units is what matters for your AGM battery. However, charging at such rates will cause severe wear and heating, is not safe and never recommended. AGM MAXĪGM batteries can technically be charged at even higher rates, well in excess of 0.3C. Fast charging also increases the battery temperature, and should be accounted for in charging voltage temperature compensation ( see previous part).ĭue to the downsides, charging rates above 0.1C should be reserved for occasional use in time-critical recharges. While possible, fast charging wears down AGM batteries and is not recommended as a standard procedure. Mastervolt, Mighty Max and UPG all give a maximum charge rate of 0.3C Victron specifies a more conservative “0.2C or less preferred”.Īdvertisements At the fast charging rates, the bulk charge stage will finish in only a few hours. Most AGM battery manufacturers also allow faster charging rates up to 0.2C…0.3C for their AGM units. With large battery packs in particular, you may actually be forced to use rates below 0.1C due to lacking charger amperage. If charging time is not an issue, charging rates much under 0.1C can also be used. While such a charge actually takes longer due to the slower absorption stage, the C-rate expression is useful in that it stays the same for all size batteries.Īdvertisements The standard 0.1C rate is a compromise between battery life and charging practicality: it is slow enough not wear or heat up the battery during charging, but fast enough to fill an empty battery overnight. This expression means a charge rate that adds 10% of battery full capacity each hour put another way, this rate would charge a battery from empty (0%) to full (100%) in 10 hours. Standard rate: 0.1CĪ standard bulk charging rate for AGM batteries is 0.1C. Absorption and float stages, by contrast, are voltage-controlled. AGM battery charging rates are specified for the bulk charge stage, which is a current-controlled stage. Battery charging rate means how fast a battery is charged in proportion to its total capacity.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |