Optima Yellow Top

[prochobo 10+ year member]

Thinking about getting one of these, but should I replace or add it in? Car is a 96 Honda Accord, 90 amp stock alt. The alt still seems to be healthy (14.22v). I'm thinking replace, what about you guys? Also, I'm seeing so many Yellow Top models, like D31, D35, 75/35, etc. which one is right for me?

A new battery and the big 3 will help voltage drops right? Cool.

Oh, and how can I calculate how long I can play my system (1500w) at full blast on just the battery power? Say it's at 100%, fully charged, how long would I play for before it dies?!

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[angryeric116 10+ year member]

bump curious as well

 

[prochobo 10+ year member]

Well I've got the answers now. Different model # indicate different sizes. Of course it helps with voltage drops, and replace, don't add unless you're using an isolator (but it will still strain your alt). If the particular yellow top you get has a reserve capacity of 120 minutes, you would be able to play for ~26 minutes off of battery. It's not recommended because it may be bad for your amp if the voltage drops below 11v.

 

[iceteebone 5,000+ posts]

i just bought a battery and i could not come up with a logical reason to buy an optima battery. unless you run your stereo with engine off, i see no advantage to an optima. do a big 3 and replace your alternator if you are not getting a stable voltage.

 

[prochobo 10+ year member]

i just bought a battery and i could not come up with a logical reason to buy an optima battery. unless you run your stereo with engine off, i see no advantage to an optima. do a big 3 and replace your alternator if you are not getting a stable voltage.

Well, I might head over to some MECA comps in the near future and they don't let competitors in the amateur class to run with the engine on. So that's where the yellow top comes in //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[photocrazy8 10+ year member]

i thought that having a battery with more CCA's allowed more time before the alt would need to crack out more amps. Thats what the Reserve Capacity rating is for? right? if im wrong please correct me. i have always wondered....

 

[prochobo 10+ year member]

http://www.autobatteries.com/faq/index.asp

"Reserve Capacity, (RC) is a battery industry rating, defining a battery's ability to power a vehicle with an inoperative alternator or fan belt. The rating is the number of minutes a battery at 80 degrees F can be discharged at 25 amps and maintain a voltage of 10.5 volts for a 12 volt battery. The higher the reserve rating, the longer your vehicle can operate should your alternator or fan belt fail."

All in all, how much power it can put out alone.

 

[photocrazy8 10+ year member]

so its how much power it can put out. so when your alt gets over run when your system and car (stock stuff) draws too much power (amps) then your battery(s) pick up the slack. correct?

 

[prochobo 10+ year member]

so its how much power it can put out. so when your alt gets over run when your system and car (stock stuff) draws too much power (amps) then your battery(s) pick up the slack. correct?

No, it's when the alternator is off (when the engine is off). That's where the "reserve" comes in, reserving juice for when there is no alt. If you've got a system and it's drawing for the battery instead of the alternator, you need an upgraded alternator.

I wouldn't say it picks up the slack, but merely helps stabilize it. E.g., alt can't handle the load, voltage drops to 12.x, battery comes in and helps keep it at 12.x and not go any lower.

 

[photocrazy8 10+ year member]

ok, cause i have a 220 alt and a 1000/1 and i can drop to 11.8.