I never trust batteries charging, so I only do it during the day so I can keep an eye on it! Tend to leave it charging all day as I don't understand the charger!!
With our charger, when you turn it on the arrow shoots to the right (if battery is flat) as it charges the arrow moves left. Sorry, i don't do technical.
I have turned the charger off as I'm now worried that I blow up the house, or get gassed. Is it safe then to charge them outside, I don,t have a socket in the garage. Sorry I sound like a numpty but am new to battery chargeing and didn't realise it could be so hazardous.