It is way better than using two Trojan 8 volt T-890 batteries to power my amplifier. Low internal impedance and standard design of 34 series. It is manufactured with pure lead My old D-1400 is still going after 4 years just like new. Measured Ohmic value is 6.9 mΩ at better than 17 volts. No sag on voltage drop and it perfect for my back up power supply. XS POWER is a great battery and highly recommend it for auto use, marine use or back up power. Great for audio applications too. kb1uku