Charging Nickel-Metal Hydride (NiMH) batteries requires understanding the relationship between capacity, current, and heat loss. Unlike Li-ion batteries, NiMH charging is not 100% efficient; some energy is lost as heat, which is why we apply an efficiency factor.
NiMH batteries are sensitive to heat. While slow charging (0.1C) is generally safe if left slightly longer, fast charging (above 0.3C) generates significant heat. Always use a dedicated NiMH smart charger for rates above 0.2C to ensure the charger stops automatically when the battery reaches full capacity.
function calculateNiMHCharge() {
var capacity = parseFloat(document.getElementById("batteryCapacity").value);
var current = parseFloat(document.getElementById("chargeCurrent").value);
var efficiency = parseFloat(document.getElementById("efficiencyFactor").value);
var resultArea = document.getElementById("resultArea");
if (isNaN(capacity) || isNaN(current) || capacity <= 0 || current <= 0) {
alert("Please enter valid positive numbers for capacity and current.");
return;
}
// Calculate C-Rate
var cRate = current / capacity;
// Calculate Time in decimal hours
var totalHours = (capacity / current) * efficiency;
// Convert to Hours and Minutes
var h = Math.floor(totalHours);
var m = Math.round((totalHours – h) * 60);
// Update UI
document.getElementById("cRateValue").innerText = cRate.toFixed(2) + " C";
document.getElementById("timeValue").innerText = h + " Hours " + m + " Minutes";
document.getElementById("decimalTimeValue").innerText = totalHours.toFixed(2) + " hrs";
resultArea.style.display = "block";
}