For a MPPT charge regulator to work accurately, the sun powered charger working voltage should be something like 4V to 5V higher than the battery charging (assimilation) voltage, not the ostensible battery voltage. By and large, this present reality board working voltage is around 3V lower than the ideal board voltage (Vmp).
All sunlight based chargers have two voltage appraisals not entirely settled under standard test conditions (STC) in light of a cell temperature of 25°C. The first is the most extreme power voltage (Vmp) which drops marginally under shady circumstances or all the more so when the sunlight based charger temperature increments. The second is the open-circuit voltage (Voc) which likewise diminishes at higher temperatures. For the MPPT to work accurately, the board working voltage (Vmp) should generally be a few volts higher than the battery charge voltage under all circumstances, including high temperatures – see more insight concerning voltage decrease and temperature beneath.
On account of 12V batteries, the board voltage drop because of high temperature is certainly not a major issue as most (12V) sunlight powered chargers work in the 18V to 22V territory, which is a lot higher than the run of the mill 12V battery charge (retention) voltage of 14.4V. Likewise, normal 60-cell (24V) sun powered chargers are not an issue as they work in the 30V to 40V territory which is a lot higher.
On account of 24V batteries, there is no issue when at least 2 sun powered chargers are associated in series, yet there is an issue when just 1 sun powered charger is associated. Generally normal (24V) 60-cell sun powered chargers have a Vmp of 32V to 36V – While this is higher than the battery charging voltage of around 28V, the issue happens on a blistering day when the board temperature increments and the board voltage can come around up to 6V. This huge voltage drop can bring about the sun powered voltage dipping under the battery charge voltage, subsequently keeping it from completely charging. A method for getting around this while utilizing just a single board is to utilize a bigger, higher voltage 72-cell or 96-cell board.
While charging 48V batteries, the framework will require no less than 2 boards in series yet will perform much better with at least 3 boards in series, contingent upon the greatest voltage of the charge regulator. Since most 48V sun powered charge regulators have a maximum voltage (Voc) of 150V, this by and large permits up to 3 boards to be associated in series. The higher voltage 250V charge regulators can have strings of at least 5 boards which is substantially more proficient on bigger sun based exhibits as it decreases the quantity of strings in equal and thusly brings down the current.
Note: Panels associated in series can deliver perilous degrees of voltage and should be introduced by a certified electrical expert and fulfill every neighborhood rule and guidelines.