Model Aircraft HC-130N, No wires have been T/S yet due to Electrics only being called out to the last two problems, First time i was called out to the plane the battery was sitting at 15volts, this of course was during a -1 ops check and the battery was dropping rapidly with both inverters on, makes sense being that both were on without external applied. We charged the battery for 30 mins bringing it up to 25volts and doing the inverter check again ops check good. This took place on a thursday, this past tuesday we get called out to the plane to the battery only holding 8 volts, let me remind anyone that this is the 3rd one changed showing the same problems. I decide to change the battery again and trouble shoot from that point with a fresh battery, with that said our back shop is only day shift it took a few hours to get a new battery to put in. this was done on swings. With fresh battery in and one thing i wanted to check was to see if the Emer Exit lights all Extinguished once the button was depressed which they all did. Thats about as far as i got then shift change came. With all power off the plane there is no indication that the battery is powering any of the buss', you can here the Gyro winding down but i was told that its normal for it to take around 15 mins for it to do so. What my question is has anyone ever seen this happen before and where might be a good place to check first and so after. could the back shop bench charger not be doing a great job at charging them. Any help is appreciated
This is a 24v 36amp/h maint free battery with its own ground wire.