I have a sealed battery. The little window appears to show a green dot, but it was certainly low on charge (am I right in my thinking that the dot indicates overall viability of the battery, but NOT the charged status of the battery). The tractor was having trouble just turning over so certainly the battery did not have a good charge. am just VERY surprised that the battery charger indicated that it was charged so quickly (2 hours). Of course this is a smaller tractor battery and not a massive SUV battery.