Cummins Diesel Battery Question

From : greg

Q: stop at most any auto parts place and have them test the battery... however if theyre the same age i suspect the good one wont last much longer after replacing the bad one... or disconnect both and check the voltages on each... better yet get a hygrometer... ah but then youll be at the parts store and they can check them for you! - hi and thanks in advance for any answers to this question and hope it will stay on topic... i have a 1998 dodge 3500 1 ton dually cummins deisel with two batteries in it...one on each side of the truck engine compartment. i have a groggy starting truck ...it is not a battery drain or short though the night or anything...i have a lemon battery amongst the two or both may be going. this is my question....how do you determine which is the faulty battery or if they are both tia....jim .

Replies:

From : tom lawrence

the hygrometer will check the relative humidity of the battery which im guessing should be right around 100% .

From : mike simmons

stop at most any auto parts place and have them test the battery... however if theyre the same age i suspect the good one wont last much longer after replacing the bad one... or disconnect both and check the voltages on each... better yet get a hygrometer... ah but then youll be at the parts store and they can check them for you! - greg the hygrometer will check the relative humidity of the battery whereas a hydrometer will check the specific gravity of the battery acid. ^ mike hi and thanks in advance for any answers to this question and hope it will stay on topic... i have a 1998 dodge 3500 1 ton dually cummins deisel with two batteries in it...one on each side of the truck engine compartment. i have a groggy starting truck ...it is not a battery drain or short though the night or anything...i have a lemon battery amongst the two or both may be going. this is my question....how do you determine which is the faulty battery or if they are both tia....jim .