how to hook up 2 batteries

Ok so i was thinkin bout adding another battery to my system..i have a optima yellow top in the engine compartment and i wanted to add another optima red top to the trunk..how would i do this? sounds like a dumb question but ive had someone tell me to wire em in series so i guess like they say the only stupid question is the one unasked.jl audio..nuff said

well may i ask why you are going to hook up a second battery im just curious if you are doing it just because your amps are making your lights dim or something along those lines that clearly means your alternator cant keep up and needs to be upgraded or use a cap now this alternator is under alot of stain you add a second battery its going to have to work twice as hard to charge that batery as well as the one in the engine compartment i would only recomend a second battery to like someone with an offroad rig or something for starting pourposes or something like that

Paulp.s i think that may be right but im not exactly positive but thats my understanding of it but again i could be wrong

downstarinc: No, not series - PARALLEL! And use an IDENTICAL battery. (Also, they should be within 6 months or so of each others age.) Yellow in front? Yellow in back. However, you need to start with your alternator. AFTER the alternator (the source of all power in the car) is up to snuf, then add all the storage (batteries) and filters (caps) you want. Leave out any kind of isolation, also. Isolating the batteries leaves you in the same position you are in right now... the capacity of one battery, which you are obviously trying to get around right now already. hobobasher: Wrong, but not completely. A fully charged battery will only require 1-2 amps to maintain its charge level, so adding a second battery will only require an additional one amp of current from the alternator. You are correct that the alternator is where he should start, but adding a second battery is not that much aditional load, nad is FAR more desirable than a cap - at least it is a POWER SOURCE, rather than a short term storage system... They will both do the same thing, but the second battery does it better, and at least actually contributes something to the overall power condition and capacity of the car.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

yeah again i wasnt too sure so thats why i didnt say thats how its done because i wasnt sure but thank you for correcting me and yeah what you said seems more logical idk what i was thinking but yeah i understand it better now atleast i was partially right with starting at the alternater so im not completly stupid lol thank you for clearifying that

well im powering a jl 1000/1, a jl 300/4, and a e-2150..i have one 1 farad cap in there already and i have another but i wanted to know if putting another battery would be better cause i dont want to have more than 2 caps..i alrady have a 140amp alternator so i think whats next is either more caps or another battery.jl audio..nuff said

add another battery it seems better in the long run like haemphyst said caps only store a small amout of power which is garbage tho it does depend on your application you have a good alternator but haemphyst also said use 2 of the same battery like use 2 optima yellow tops and they should at no more then 6 months in age difference which is basicly the exact same thing haemphyst said so i guess do what he said cuz i did some research and he is correct i just wanted more info on it so run them as he said and you should be fine and get rid of the caps if your adding a second battery the caps wont be neccesary but make sure both batteries have a full charge before you put them in the vehicle

if you ran them in series you would end up with 24 volts..... to run parallel   run them  positive to positive negative to negative

Wouldn't 24 volts hold up better than 12 volts when having a big system? My system drops my voltage to 10 volts when the bass is up. I have two batteries and one cap. Stock alt so far but having trouble locating an alt for my 88 Legend.

menace2sobriety wrote: if you ran them in series you would end up with 24 volts..... to run parallel   run them  positive to positive negative to negative

you would burn out a lot of crap with 24 volts. your audio system for one.  tw0 everything in the car that is powered. find a shop that rebuilds alt,s they can upgrade your alt to a higher amprage but its limited on how much.

menace2sobriety wrote: you would burn out a lot of crap with 24 volts. your audio system for one.  tw0 everything in the car that is powered. find a shop that rebuilds alt,s they can upgrade your alt to a higher amprage but its limited on how much.

Thanks!