electrical:12v:battery_capacity
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electrical:12v:battery_capacity [2017/08/25 21:12] frater_secessus [Examples] |
electrical:12v:battery_capacity [2021/05/03 10:33] frater_secessus [other than 20hr rates] |
====== C notation ====== | ====== C notation ====== |
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Battery capacity in Amp-hours is written as **C**. This notation is most useful when talking about charging/discharging rates. | **Battery capacity** in Amp-hours is written as **C**. 100Ah, for example. |
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Note: most deep cycle manufacturer's rate capacity at C/20, due to Peukert effect. | C notation can also be used to describe the **relative amount of current** charging/discharging battery bank. For example a 50A load on a 100Ah bank would be C/2 (100/2 == 50).((technically C/20/2, but that form is rarely seen outside formal documents)). It may also be written as 0.5C.((decimal vs. fractional expression, can be used interchangably)) |
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| Note: most deep cycle manufacturer's rate capacity at C/20, due to Peukert effect on lead chemistries.((Lithium doesn't not have a significant Peukert effect. Capacity measured by C/20 and by amp-counting will be nearly identical)). In other words, a 100Ah battery will deliver 100A with a 5A load. See table at bottom for other load levels. |
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If the manufacturer says that [[electrical:12v:charging|Absorption stage]] is complete when charging current has dropped to C/100 or C/200 then the current to watch for would be 2A (200/100) or 1A (200/200). | If the manufacturer says that [[electrical:12v:charging|Absorption stage]] is complete when charging current has dropped to C/100 or C/200 then the current to watch for would be 2A (200/100) or 1A (200/200). |
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| ===== other than 20hr rates ===== |
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| Because of the Peukert effect, lead bank //measured// capacities are strongly affected by dicharge rate. Sample data below is for flooded lead acid. C/20 capacity is multiplied by the factor below to find projected capacity at given discharge rates. |
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| 1 Hour = .3 \\ |
| 2 Hour = .5 \\ |
| 3 hour = .6 \\ |
| 4 hour = .65 \\ |
| 5 hour = .7 \\ |
| 6 hour = .75 \\ |
| 8 hour = .8 \\ |
| 10 hour = .85 \\ |
| 12 hour = .9 \\ |
| 16 hour = .95 \\ |
| 20 hour = 1 \\ |
| 24 hour = 1.05 \\ |
| 36 hour = 1.1 \\ |
| 72 hour = 1.25 \\ |
| 100 hour = 1.30((vhttps://www.solarpaneltalk.com/forum/off-grid-solar/batteries-energy-storage/11731-peukert-law-batteries-and-you#post11731)) |
electrical/12v/battery_capacity.txt · Last modified: 2022/09/22 12:19 by frater_secessus