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electrical:solar:charge_controller [2020/01/07 23:02] frater_secessus [how to choose] |
electrical:solar:charge_controller [2020/05/25 11:54] frater_secessus [how to choose] |
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There are //DC-DC converting charge controllers// | There are //DC-DC converting charge controllers// | ||
==== how to choose ==== | ==== how to choose ==== | ||
- | **PWM is the default choice** in most situations because they get the job done in most scenarios | + | **PWM is the default choice** in most situations((12v house power, 12v panels)) |
If more power is needed (and there is physical space) additional PV can be added to match the charging output of an MPPT charger, often at a lower cost. [There are no prizes for fanciest or most expensive charge controller! | If more power is needed (and there is physical space) additional PV can be added to match the charging output of an MPPT charger, often at a lower cost. [There are no prizes for fanciest or most expensive charge controller! | ||
- | MPPT controllers also tend to consume more power to run themselves than PWM models due to additional processing and electronic components. | ||
- | There are also edge cases where PWM can make more power than MPPT on poly [[electrical: | + | There are also edge cases((low altitude, high temperature, |
- | **MPPT may be a better fit** when: | ||
- | * battery banks are cycled deeply on a regular basis so more time is spent in Bulk | ||
- | * nominal 12v panels have a relatively high Vmp (>=18v) for [[https:// | ||
- | * [[https:// | ||
- | * high latitudes | ||
- | * overcast or rainy weather | ||
- | * if the camper will be used in areas of partial shade((http:// | ||
- | * canyon or "urban canyon" | ||
- | * forested areas | ||
- | * if temperatures are very low (greater harvest) | ||
- | * the increase in cost is not an undue burden | ||
**MPPT is effectively required** when: | **MPPT is effectively required** when: | ||
- | * using panels with nominal voltages higher than 12v | + | * using panels with nominal voltages higher than 12v ((more prescisely, when panel nominal voltage exceeds house bank nominal voltage)) |
* space available for panels is limited, as on a sailboat or small vehicle | * space available for panels is limited, as on a sailboat or small vehicle | ||
+ | * daytime loads are hampered by [[electrical: | ||
* [[# | * [[# | ||
* making [[electrical: | * making [[electrical: | ||
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**Shunt controllers are useful for [[electrical: | **Shunt controllers are useful for [[electrical: | ||
Their simple ON and OFF setpoints may also make them useful for charging [[electrical: | Their simple ON and OFF setpoints may also make them useful for charging [[electrical: | ||
+ | |||
Further reading: | Further reading: | ||
[[https:// | [[https:// | ||
+ | |||
+ | **MPPT may be a better fit** when: | ||
+ | |||
+ | * the existing PWM system is not providing enough output | ||
+ | * battery banks are cycled deeply on a regular basis so more time is spent at low Vbatt where PWM struggles. | ||
+ | * nominal 12v panels have a relatively high Vmp (>=18v) for [[https:// | ||
+ | * if multiple panels will be used in areas of [[electrical: | ||
+ | * if temperatures are very low (rising Vmp means increasing output which PWM could not capture) | ||
+ | * the increase in cost is not an undue burden | ||
+ | |||
===== multiple charge controllers | ===== multiple charge controllers | ||
[[electrical: | [[electrical: |