Comparative Battery: LiFePO4, Li-Ion and Lead / acid

How is it possible that a lithium battery has a capacity (Ah = ampere-hour) equal to about 1/3 compared to a battery equivalent to lead / acid? How is it possible that, despite this lower capacity, its inrush current (AC = Cranking Ampere) is 50% higher than lead acid batteries?

Comparativa batterie: LiFePO4, Li-Ion e Piombo/Acido

In order to understand these data, shown in the tables and in the graph, the concepts of energy density (Wh / L) and maximum discharge current must be introduced. LiFePO4 batteries have in fact an energy density up to five times higher than equivalent lead / acid batteries.

Construction typology

 Lead/Acid LiCo (Lithium
Cobalt) /
Li-Ion 		LiFePO4
BC LITHIUM

Nominal tension

[V] 		2,1 3,6/3,7 3,2

Energy density

[Wh/L] 		Medium High High

Specific energy

[Wh/Kg] 		Medium High High
Discharge rate max.
(Discharge rate) [C] 		15 N.D. 50
Safety

Discrete

(presence of toxic materials)

 Low

(risk of fire and explosions)

 Excellent

(no risk of fire / explosion)
Life Cycles
 > 400 > 500 > 2000
Eco-friendly Product No No Yes

 

The result is that, with the same volume occupied, a lithium battery will have up to five times the energy compared to a battery equivalent to lead / acid. Lithium-ion batteries (Li-Ion or LiCo) have an even greater starting point, but in the face of a level of safety not comparable to LiFePO4 technology for automotive applications. In addition, the maximum discharge current of a lithium battery is 50C, therefore fifty times the battery capacity, more than triple that of lead / acid batteries. Therefore, if a motorbike requires a starting current (AC) of 300 A, if with traditional lead / acid batteries it would be necessary to use a battery of at least 20 Ah (15x20), if using a lithium battery a 4 Ah (50x4) battery will suffice.

BC LITHIUM
BATTERIES
Models

Corresponding Lead/Acid Battery

 BC
LITHIUM
Capacity
(Ah)		 Lead/Acid battery Capacity
(Ah)		 BC
LITHIUM
Weight
(Kg)		 Lead/Acid battery
Weight
(Kg)		 Weight Difference
(Kg) 		BC
LITHIUM
CA
(Amp)		 Lead/Acid battery
CA
(Amp)		 Increase
Cranking
Amps (%)
BCTX5L-FP-S YTX5L-BS 1,6 4,0 0,5 1,6 1,1 105 70 50%
BCTX7L-FP-S YTX7L-BS 2,0 6,0 0,6 2,3 1,7 160 85 88%
BCTX9-FP YTX9-BS 3,0 8,0 0,8 2,5 1,7 180 120 50%
BCTZ10S-FP YTZ10S 4,0 8,6 0,8 3,2 2,4 240 150 60%
BCT12B-FP YT12B-BS 5,0 10,0 1,1 3,4 2,3 300 190 58%
BCTZ14S-FP-S YTZ14S 4,5 11,2 0,9 3,9 3,0 290 230 26%
BCTX20H-FP-SQ YTX20HL-BS 7,0 18,0 1,4 5,6 4,2 420 270 56%