Load Testing a pair of T-105's
Can anyone provide numbers that you have recorded so I can compare to see if my pair are in the ballpark? Im getting about 10 hrs @ 10 amps to 50 percent level... I just replaced a pair that after...
Forum Discussion
Your new T-105s should have been fully charged at 14.8v from a deep cycle and then overcharged as required to get their SG right up to spec before starting the test. Just being at 12.75 is not enough evidence of being full after first getting them home new.
The inverter causing unusually low voltage for the same amps as before could be a sign of that. Or you have a wiring issue with the new installation adding to the R the inverter sees.
The 20 hr rate on a pair of T-105s is 11.25 amps (225/20) so 10 is not enough for this test. You do need the hydrometer to know when you are near 50% (which can come early if they are not at 225AH--eg they can be sulfated or just in the cold. At 45F they would be down about 10% to 202AH approx.)
Of course if they are in the cold and at 202 then now your 10a is about right. I stay with the 11.25 and adjust the AH results for temp afterwards. Not too sure how you are supposed to deal with that properly.
The 11.9v seen after a time is the loaded voltage so you have to wait a bit after removing the load when your hydrometer says they are at 50% (1.175ish ) to see what voltage they bounce back to. Should get to 12.1ish within an hour. Don't expect perfect line up between the SG and bounce back voltage for the 50% marker. If you have an AH counter that also helps. You have to get then all close enough and just "declare victory."
Don't forget temperature!!! If it is 50F instead of 80F your spec hydrometer SG will be higher, your voltages lower, and the adjusted correct capacity will be lower too.
IE, your 50% SG marker will be higher than 1.172, your bounce back voltage will be under 12.1, and your time will be less than 10 hours for under 225 and it will all be good as. Temperature!!!!
The inverter causing unusually low voltage for the same amps as before could be a sign of that. Or you have a wiring issue with the new installation adding to the R the inverter sees.
The 20 hr rate on a pair of T-105s is 11.25 amps (225/20) so 10 is not enough for this test. You do need the hydrometer to know when you are near 50% (which can come early if they are not at 225AH--eg they can be sulfated or just in the cold. At 45F they would be down about 10% to 202AH approx.)
Of course if they are in the cold and at 202 then now your 10a is about right. I stay with the 11.25 and adjust the AH results for temp afterwards. Not too sure how you are supposed to deal with that properly.
The 11.9v seen after a time is the loaded voltage so you have to wait a bit after removing the load when your hydrometer says they are at 50% (1.175ish ) to see what voltage they bounce back to. Should get to 12.1ish within an hour. Don't expect perfect line up between the SG and bounce back voltage for the 50% marker. If you have an AH counter that also helps. You have to get then all close enough and just "declare victory."
Don't forget temperature!!! If it is 50F instead of 80F your spec hydrometer SG will be higher, your voltages lower, and the adjusted correct capacity will be lower too.
IE, your 50% SG marker will be higher than 1.172, your bounce back voltage will be under 12.1, and your time will be less than 10 hours for under 225 and it will all be good as. Temperature!!!!
