**CLOSED**GROUP BUY**NORTHSTAR DEEP CYCLE BATTERIES**

What was the ambient temperature?

 

The test results were: 302 CCA, 12.8 V @ 58 degrees

 

Was the battery fully charged before it was tested? Some conductance testers are not very accurate below 50% State-of-Charge. At 58 degrees, I would expect it to be the CCA to be within at least 90% of the manufacturer's CCA spec.

Was your battery fully charged when it was cranking slowly? The reason I ask is because if the battery was undercharged it will will not produce the performance (cranking amps). If the battery has been continually undercharged due to driving habits or excessive electrical parasitic or operation load, it will gradually lose both performance and capacity due to slow buildup of lead sulfate on the plates. More often than not when the OEM load design is exceeded with the addition of aftermarket accessories, the alternator can not keep the battery fully charged. Cold temperatures just exacerbates the problem.

If it were my battery, I would fully charge (12.8 volts @ 77 degrees F after the surface charge is removed) it and take it and have it retested for performance (CCA) and capacity (Amp Hours (C/20) or Reserve Capacity). If it does not meet or exceed 80% of the manufacturer's spec and free replacement warranty, I would request a new battery.