New Battery or Big 3

[genericmoniker]

Figured this was more suited for the electrical section than the I.C.E, but mods please feel free to move if necessary.

A little bit of background on my car, ended up getting a brand new OEM battery about 6 months ago (warranty work). Alpine MRP-M500 feeding a JBL GTO1214D, currently have it turned all the way down for reasons to follow.

I notice my lights dim at the oddest times, such as when coming to a stop, turning the wheel a full turn, or the last second of winding the windows all the way up. Now, these existed before I had my amp installed. Now at moderate volumes (say, 20/50 on the OEM deck) I see the lights dim quite heavily on the bass hits, turning the amp up any more and I see dimming as low as 12 or 15.

My question is, which do you guys feel would be more beneficial to my car? A yellowtop or similar, or a big 3 upgrade. I have an inkling that the charging system on this car is subpar, and will eventually get both but in my current situation it's not feasible for me to ante up and get both at the same time. A few of the guys over at the other forum have suggested a new alt, just wondering what the stocker is rated at?

 

[kcdirtbro54]

Do you or have you tried installing a capacitor with your sound setup? I'll first say that I am by no means an "ICE" expert, but I've installed many many audio setups and I've noticed that with others' and even my own setups that a capacitor usually solves issues like this and similar to what you're talking about. If I remember correctly,you're looking for 1 Farad for every 1000 watts. Capacitors are measured in Farads by the way. Basically they supply constant power to the audio equipment so that there aren't any dips or spikes in voltage from you charging system. That's what I would do first and honestly, I don't understand why people don't install them when they add subs and amps. They aren't terribly expensive and are very simple to install.

 

[genericmoniker]

Fairly familiar with capacitors and how they work, trying to stay away from them in this instance though. Appreciate the thought and concern though.

 

[kcdirtbro54]

Why not? Installing one will usually fix your issue, or at least help with it. And they're a lot cheaper than buying optima batteries and upgrading alternators and very easy to install.

 

[Gravity]

Caps are all well and good, except AGM batteries like Yellowtops and Kinetik power cells have a much lower ESR, which means they discharge faster and deliver more on demand power. A Kinetic HC600 delivers more power than a cap, and discharges faster for less money (unless you buy really cheap caps). Additionally, a capacitor puts a higher strain on the charging system and doesn't really provide you with more power.

A Yellowtop or other AGM battery will probably solve a number of your issues, simply because they have a higher current reserve than stock. A small power cell added to that rig will function better as a 'stiffener' than most caps and provide you with true extra reserve power, even when the engine is off or not revving as high. Also, given that a Kinetik HC600 runs about $150 and most 1-2F caps run around 150-200 (for any kind of quality) you're getting much better bang for your buck.

A big 3 upgrade is another great option. In our cars the alternator and battery grounds are like 6-8awg. I went to true 2awg for alt and battery, and true 4awg for other engine grounds. I'm using TRUE 4awg for all amp rack wiring. It does help with power delivery for sure. If you invest the cash in a yellow top then a big 3 upgrade is also worth the cash. You don't need more than maybe 8ft of cable in our cars. To be fair tho, a big three upgrade alone isn't likely to fix your issue much.

I specify 'true' AWG above because many manufacturers will call their cable Xawg, using the cmil measurements for SOLID wire. Since solid wire has more copper for a given cmil size, stranded wire awg measurements are larger (usually around 5-10%) I've even seen some wire manufacturers (*COUalpineGH*) sell 8AWG cable that was barely 10AWG.

Your M500 isn't drawing more than maybe 45A total though, even at full crank... And even at that since the duty cycle of audio is fairly low (something like 20%-50%) at average levels you're not likely to draw close to that much.

I should note that since you're only running a single amplifier, it's probably not worth major upgrades. A single yellowtop is likely to cure all your issues without putting undue strain on the charging system. It's also easier to install and doesn't require stashing one more component somewhere.

If you were running a couple higher powered amps and deck and were primarily concerned about SQ, than it's definitely worth doing all 3.

I say get a yellowtop and be done ;-)

 

[Gravity]

oh yea.. the stock alternator is around 80-90A IIRC

 

[genericmoniker]

Just the sort of advice I was looking for. Chances are I'll be grabbing a yellowtop before the new year, or slightly after and big 3 will be sometime closer to next summer.

 

[DrWebster]

Supposedly Optima batteries aren't made like they used to be...I've read a lot of bad reviews about them recently. If you do go with a new battery, my only recommendation is to shop around and read a lot of reviews first.

 

[Gravity]

This is certainly possible.. I've read a few bad reviews. That being said, I've got a redtop in my RX8 and a yellowtop in my 2 for more than a year now and had zero issues. They perform as advertised for me!

The other option is that Kinetik HC1600 (i think) can be used as a starting battery and has even lower ESR than yellowtops. More expensive tho.