LiFePo Battery Difference

o1marc

I see these 4200 LiFePo batteries successfully used in pairs for starting a Mazda Miata. I found some 5000's and was wondering if that might not be better, but they have numbers that make me question it. With the stats below, would I better with 2-5000's or 2-4200's.

Capacity: 4200mAh
Voltage: 4S2P / 13.2v
Discharge: 30C Constant / 40C Burst
Max Charge Rate: 2C
Weight: 558g (including wire, plug & case)
Dimensions: 140mm x 45mm x 46mm
Balance Plug: JST-XH
Discharge Plug: 5.5mm Bullet-Connector

Capacity: 5000mAh
Voltage: 2S1P / 2 Cell / 7.4v
Discharge: 20C Constant / 40C Burst
Weight: 240g (including wire, plug & shrink wrap)
Dimensions: 144x49x18mm
Balance Plug: JST-XH
Discharge Plug: HXT 4MM

mvas

Are you going to use these batteries for Off-Grid Solar?
Starting a car in second or two is very different vs running a DC-to-AC inverter for many hours.

4200 mAh = 4 Amp-Hour
5000 mAh = 5 Amp-Hour

Do you have a URL link for each?

Raj174

Are you sure the 5000 is LiFePO4? The voltage is a little high, more like lithium polymer cell voltage of 3.7v. And at 2S1p, not the same voltage (7.4v) as the 4000 (13.2). So it doesn't sound like it would work in place of a 4000.