Thor Forums

[FW28z]

Jamie; I think you have a bad battery. Either that or something is seriously discharging your battery as a stereo's keep alive should not discharge your battery that quickly.

Say your battery has an 80AH rating; disregarding Peukert's law for a few moments, if your battery is discharging in 24 hours (and 8v is seriously discharged), that means you have a parasitic load of nearly 4Amps! A stereo keep alive is maybe a few mA.

So if the battery is good, something else is going on.

Even when fully discharged, a wet cell should still produce about 11.8V, and when fully charged, about 12.6V. These are of course, no-load voltages (battery disconnected and resting for at least an hour), without the alternator running.

Of course, one way to determine if you have a battery or load problem is is with a clamp-ammeter like the B&K 316... but hey; you have the opportunity for a new tool.