You do not have a 1150 mAh (milliamp-hours) charger. There's no such thing. It might be an 1150 mA (milliamp) charger, which means it's only providing 1.15 amps of charging current. Some batteries require a minimum current to charge very well.
My Samsung smartphone, for instance, requires a 1500mA charger. If I try to use a 700 mA (0.7A) or 1000 mA (1.0A) charger with it, it takes days to charge it only a little bit, like from 65% to 70%. If I use a 1500 mA (1.5A) charger, it takes a couple of hours to fully charge it from around 20%.
But my guess is that is not what's going on here.
What usually causes a Canon charger to blink fast to indicate a battery it won't charge is that the battery in question is either:
- An older third party version of the Canon battery.
- A battery that has been allowed to become so depleted that the Li-Ion chemistry makes it dangerous to attempt to recharge it
Third party issues
Canon includes certain "hidden" or "unused" parts of code in the firmware of their proprietary batteries. The original versions of those batteries, chargers, and cameras that use that particular model battery do not call on those "hidden" parts of the code included in the batteries' firmware. After a few years, Canon often updates a battery and creates newer cameras and chargers that do call on some of that "hidden" code that was included at the beginning.
When third party battery makers clone batteries for use with Canon cameras, they "reverse engineer" them based on the signals they can measure between the battery and the cameras available to them at the time they design their battery and charger. As long as the "hidden" code in the firmware is not being used in the communications between the camera and battery, the reverse engineered code in the third party battery will not include it. Once Canon updates the firmware running their chargers and cameras, the code "hidden" in older Canon version of the same battery will allow those batteries to be used with the newer cameras and chargers. But the third party batteries that do not have that extra bit of code will often not work properly in the newer cameras and chargers.
It usually only takes the battery makers a few weeks to update the firmware of the batteries they are making so that they will work with the newer cameras models and the ocaissional new firmware for the battery charger. But that doesn't do much good for the third party batteries you already have. If you've only recently purchased the third party batteries, sometimes the seller will allow you to swap copies of the older version of their knock-off for a newer version of their knock-off for the same battery.
Depleted below minimum voltage
Li-Ion batteries have minimum amounts of energy they need to contain before they are no longer functional in most chargers and dangerous to recharge. They can catch on fire! If your battery has been depleted below that point, the Canon chargers will refuse to charge it. Sometimes putting the older battery on a third party charger will apply enough current to get it back over the minimum energy level without causing a fire.
An OEM Canon LP-E6 battery that came with a camera I got back in 2011 got to where it wouldn't charge on any of my official Canon chargers. On a whim before I tossed it, I put it on a third party charger I have. The charger was able to recharge the battery and now even my Canon chargers will happily charge it again. It's been a few months and several recharge cycles and it still works (though any Li-Ion battery that old will have diminished capacity compared to a brand new copy of the same battery model).