Test Results: The Lead-Acid Battery  versus LiFePO4

The chart shows the huge difference between a lead-acid AGM and the LiFePO4 batteries. The discharge was done from full voltage (full charge) to the same 9.9V level.

Capacity: the AGM battery nominal capacity is 44AH, the nominal capacity of LFP is 40AH. In reality the usable energy of the AGM was only 288Wh (24Ah @12V - at 36 minutes). The usable energy of the LFP was 504Wh (42Ah@12V - at 63 minutes). Difference is obvious: 44AH AGM gives 288Wh, 40AH LFP gives 504Wh. The difference is 52% vs 100%. Simply said the bigger 44AH AGM is just half of the smaller 40AH LFP.

Discharge time: the AGM 44AH battery is running only for 36 minutes. The LFP 40AH is running for 63 minutes. Again nearly a double time.

Note: the discharge was done by the same current of 40A. In fact, this means we were more kind for the AGM battery. To be 100% fair at the same 1C discharge rate, the AGM should be discharged by 44 Amp current. The results for the AGM would be even worse….

Our advise is: in the 2015, please forget about AGM and other lead acid batteries, simply say good-bye to this 19th century technology.