| Both sides previous revision
Previous revision
Next revision
|
Previous revision
Next revision
Both sides next revision
|
electrical:solar:charge_controller [2019/09/28 17:21]
frater_secessus [how to choose] |
electrical:solar:charge_controller [2019/10/01 13:04]
frater_secessus [how to choose] |
| We say "effectively required" because one //can// use 24v panels with PWM and 12v banks -- it just doesn't work very well. The 24v panels will be run at 12v voltages, yielding about half the power you would get with MPPT. | We say "effectively required" because one //can// use 24v panels with PWM and 12v banks -- it just doesn't work very well. The 24v panels will be run at 12v voltages, yielding about half the power you would get with MPPT. |
| **Shunt controllers are useful for [[electrical:solar:shallow_cycling|shallow-cycling configurations]]** or for battery chemistries that are not damaged by [[electrical:depth_of_discharge|partial state of charge (PSoC)]]. Their relative inexpense makes them useful for even very small systems and test configurations. | **Shunt controllers are useful for [[electrical:solar:shallow_cycling|shallow-cycling configurations]]** or for battery chemistries that are not damaged by [[electrical:depth_of_discharge|partial state of charge (PSoC)]]. Their relative inexpense makes them useful for even very small systems and test configurations. |
| Their simple ON and OFF setpoints may also make them useful for charging [[electrical:12v:lifepo4_batteries_thread|lithium]] chemistries. | Their simple ON and OFF setpoints may also make them useful for charging [[electrical:12v:deep_cycle_battery#lithium_chemistries|lithium]] chemistries. |
| Further reading: | Further reading: |
| [[https://www.victronenergy.com/upload/documents/White-paper-Which-solar-charge-controller-PWM-or-MPPT.pdf|an excellent and readable whitepaper by Victron]] (PDF). | [[https://www.victronenergy.com/upload/documents/White-paper-Which-solar-charge-controller-PWM-or-MPPT.pdf|an excellent and readable whitepaper by Victron]] (PDF). |
| [[electrical:12v:multipoint_charging|Multiple controllers (with separate arrays) can be used to charge a common bank]]. The controllers should be configured with similar charging setpoints for the greatest efficiency.((http://www.morningstarcorp.com/parallel-charging-using-multiple-controllers-separate-pv-arrays/)) | [[electrical:12v:multipoint_charging|Multiple controllers (with separate arrays) can be used to charge a common bank]]. The controllers should be configured with similar charging setpoints for the greatest efficiency.((http://www.morningstarcorp.com/parallel-charging-using-multiple-controllers-separate-pv-arrays/)) |
| ===== sizing your charge controller ===== | ===== sizing your charge controller ===== |
| As with [[electrical:inverter|inverters]], sizing the controller correctly will help system efficiency. An oversized CC will have unnecessarily high parasitic drains as it powers itself. An undersized CC will not be able to put all the rated solar wattage to use and will leave no room for expansion. | As with [[electrical:inverter|inverters]], sizing the controller correctly will help system efficiency and save money. An oversized CC will have unnecessarily high parasitic drains as it powers itself and will cost more. An undersized CC will not be able to put all the rated solar wattage to use and will leave no room for expansion. |
| For PWM controllers, the formula is something like (panel wattage / 13) * (1.2 oversize for safety) = charge controller amps.((https://www.altestore.com/howto/sizing-pwm-solar-charge-controllers-a91/)) | For PWM controllers, the formula is something like (panel wattage / 13) * (1.2 oversize for safety) = charge controller amps.((https://www.altestore.com/howto/sizing-pwm-solar-charge-controllers-a91/)) |
| MPPT controllers have more leeway in sizing since they can control the output of the panels independently of battery voltage. | MPPT controllers have more leeway in sizing since they can control the output of the panels independently of battery voltage. |
