Rep Power: 0

Ok so i have a stock Battery (about 2 yrs old 450cca), OEM alternator, (70 amp max, 38amps @ Idle)
I have 1. 55wHID for the headlights 2. 35wHID foglights 3. 300.1 kicker amp 4. 200watt pioneer deck.

My problem is this....while having both headlights and foglights on, with the stereo a little under comfortable listening volume....and sitting at a stoplight for about 2 mins....one of the foglights will go off..... as soon as i get on the gas again it will come back on.

I had the bettery checked and alt check and both are fine and fully charged, My question is which do i need to upgrade...battery(optima red top..150-170ish) or the alternator (HO 200+). I just want to be sure i know what the problem is before i go droppin mucho time and denero into something that is not the problem. Thanks.

 
Rep Power: 812

eh yeah you have alot of things on at night. but then again, oem fogs and headlights are 55wx4 which is more than what you have. its still alot of power draw tho. you could use a bigger alternator just to run accessories more comfortably, but i think the hid kit is the problem. most of those are cheap china junk and have all sorts of issues. a real ballast would continue to function just fine even at only 11v. it may also be your fog wire harness. but if the fog is turning off after it warms up, its prolly just not getting enough power. have you tested your output voltage at night with everything turned on? if it dips really low below 12v id say its time for a new alternator that puts out more amps. a 500cca battery may be nice next time (no need to spend money on useless optimas that suck), but batteries wont solve low power problems, they will just take longer to drain down. if the stock alternator cannot make enough power to run the car AND charge the battery, not even the best and biggest battery will matter. it will still get drained eventually.

 
Rep Power: 313

Optimas suck??? what type of battery do you recommend? I always thought optimas were good but on the other hand i have NO experience with them whatsoever... best battery i ever had was a john deere(believe it or not) and it was in my S10!!!

 
Rep Power: 0

I have a motorcycle battery in my evo with both HID fogs and headlights, no problems with my stock alternator.

 
Rep Power: 812

regular lead acid batteries are great. for our cars that only come with 420cca, i upgraded to a 500cca group51 and its much better suited for the car. i just got one from advance auto called autocraft titanium. the honda dealer has 500cca grp51 size also i think interstate makes them and they slap a honda sticker on. thats prolly what ill get next time. or whatever good one the auto store has. just check the water levels every few months and keep the battery full with distilled water. optimas are junk, search around and almost every forum hates them. i had a yellowtop that crapped out after 1.5 yrs.