I have a YT7B-BS battery in my motorcycle. My motorcycle doesn't start because the battery voltage is only 12.05 Volts.
The battery has the following inscriptions:
- Standard charge: 0.7 A x 5~10 hours
- Quick charge: 3 A x 1 hours
- 6.8 Ah (20 HR) / 110 A (CCA)
- 12 V, 6.5 Ah (10 HR)
I tried to charge the battery with an external hard drive power supply rated as following:
- Switching adapter
- Model SYS1298-1812-W2E
- Input: 100-240 V ~ 1.0 A MAX, 50-60 Hz
- Output: +12 V continous 1.5 A
- Output power: 18W max
I have plugged the positive terminal of the power supply to the positive terminal of the battery, and the negatives to the negatives. After a 2 hours, the battery voltage is exactly the same: 12.05 V. The power supply is a little warm but not too much.
I plugged the motorcycle battery to my car battery for a few minutes and the tension went up to 12.5V, allowing my motorcycle to start (battery alone, no cables), so the battery doesn't seem to be dead.
Why isn't the power supply charging the motorcycle battery?
Best Answer
A 12V battery needs a higher voltage to charge. You're using a 12V HDD power supply with outputs a constant voltage to charge a battery that already presents 12V across its terminals. No current will flow from the power supply to the battery. If it was discharged even more however, you will be able to charge it up to 12V (Whatever the equivalent State of Charge corresponding to that voltage is).
Try using a 14V supply, and preferably with a current limitation (@3Amp MAX) feature so that you won't damage it.