Optima Battery Question and how much juice do I need

[Chexi]

I just picked up 1 Optima SC34M (starting) and 2x Optima SC32DM (dual purpose) batteries for $155 + $9 core charge each minus $20 mfg. rebate per battery (total of 3). The rebate looks good at any authorized dealers, so if you have been holding out on buying, now is a good time. Rebate lasts until 4/30/09.

http://www.optimabatteries.com/save6...ebate_Form.pdf

Okay, with that said, I'm wondering a few things.

1. Do I lose anything significant in play time on the dual purpose compared to a deep cycle only? Any experiences, good or bad with these dual purpose Optimas would be appreciated.

2. Do I gain any real world cranking benefit with the starting Optima instead of the dual purpose? They were the same price where I bought them (Sam's Club), but I think the dual purpose is usually more expensive. They had 1 more dual purpose in stock, and since they are normally more expensive, I wonder if I would be better off getting 3 dual purpose instead of the 2 and 1 I got.

3. My audio system is 1 x 550 4 channel amp plus 1 mono x 450 amp. I'll be running 2x 12" subs in parallel off the mono amp and 2x kicker KMT6 towers and 4x kicker 620s off the 4 channel amp. I don't expect to do a whole lot of cranking the system when the motor is off, but it will happen from time to time. But, if I use 3 batteries, I'm pretty sure I need to also upgrade the alternator to the 100amp unit. So, does my system really need the third battery? I probably don't need the 2nd sub and could disconnect that one if it would make a difference.

Thanks.

[gride300]

RE: Optima Battery Question and how much juice do I need

install an isolater and you can crank it with the engine off all day long

[Chexi]

RE: Optima Battery Question and how much juice do I need

I will have an isolator, so I'm not worried about killing the starting battery. I just have no experience with these batteries or deep cycle batteries at all. With the engine off I don't know if I'll have 10 minutes of power or 10 hours of power. If I can get 3 hours of power with moderate volume on 1 deep cycle battery, I don't need 2. I'm just clueless on this stuff.

[Quinner]

RE: Optima Battery Question and how much juice do I need

Scott,

I have 1 battery, Spring 08' replaced the original battery with a dual purp Blue Top. There were a few times we played loud music for over an hour without a problem. Running 2 amps, 640w & 800w, NVS Tyrants, 6 polks & 1 sub. The key is going out with a full charge if you know you will be pushing it. Personally think 3 Batt in your application is overkill however if you are not concerned about the added weight or don't mind buying a 3rd, then have at it.

[Chexi]

RE: Optima Battery Question and how much juice do I need

Quinner, so you have only 1 battery total? Is it the 34 (mid-size) or the big 31? Do you have the 100 amp alternator? Might be standard in your 206. I ask because I wonder if I need the 100 amps just to be able to power the audio system while running without draining the audio batteries.

[AuMDLST]

RE: Optima Battery Question and how much juice do I need

Chexi - I would go with the 100 amp alternator and a battery jump box just in case. For get the jump box unless you are out in the middle of nowhere - in that case you should have one any ways. I am running the factory 100 amp alt with the factory batteries (2) pushing:
Kicker 850.4 (Tower)
Kicker 750.1 (Sub)
Clarion 480 (4 Cabin Speakers)
Clarion 280 (2 Bow Speakers)
Batteries are always charged as much as possible due to frequent use and the stereo has been played for several hours without hesitation at start up time.

Just seems like a big ordeal for the same piece of mind you can get with a $100 jump pack - IMO

[Chexi]

RE: Optima Battery Question and how much juice do I need

I am leaning toward taking the starter battery back, keeping the two dual purpose, and probably getting the 100 amp alternator, which the returned battery will partly pay for. This way, if it turns out I need a third battery, at least I have 2 identical batteries that have been used (albeit for different purposes) for the same amount of time, which I can then combine for the audio after reconditioning on my CTEK charger/reconditioner. If I kept the 1 starter and 1 dual purpose, I'd technically have to 86 the dual purpose when I added a newer one. I will consider a jump pack, although I will always be within swimming distance of land. With the isolator in place, I think it would be improbable to lose both batteries at the same time, albeit not impossible. It's possible one could run down the audio battery and have a failure on the main at the same time.

[N2Orbit]

I was told that Optima's were the best. I have not had very good luck with Optima battery's though. I am on my fourth one now. At one time I had three of them in my SAN and had nothing but trouble. This winter I will replace them with three standard marine batterys. Any recommendations?

[Quinner]

Re: RE: Optima Battery Question and how much juice do I need

Quinner, so you have only 1 battery total? Is it the 34 (mid-size) or the big 31? Do you have the 100 amp alternator? Might be standard in your 206. I ask because I wonder if I need the 100 amps just to be able to power the audio system while running without draining the audio batteries.

Want to say I have the 34, the boat came with the 100amp alternater. If I am going to be out and really pushing the stereo hard while floating I bring my jump box with just in case. For me the deciding factor on a 2nd battery was all about weight, keeping the wake as small as possible.

Have heard good and bad reviews on the optimas, had 2 in my Suburban that lasted about 7 years with no issues, this is my first go at a marine version, time will tell that tale.

[jaybird]

Audio run time

Chexi,

You can estimate the power reserve of your audio with engine off by the "reverse minutes" rating on most battery’s. This is the time you can run at 25 AMPS from full charge until the battery voltage drops to a unusable level.

If you have for example a 1000-watt system you probably only use it at 30-40% volume so for the sake of discussion lets call that 400 watts. 400W/12Volts = 33 amps. I run the D31M Optima's. I have one for cranking and one for my audio system. My Optima D31M has a rating of 155 minutes at 25 amps thus it would run at 33 amps for approximately 75% of the 155 minutes or 116 minutes. Look at your battery “reserve minutes”. I went to the optima web site but could not find the battery number SC32DM.

When I have my boat in the garage working on it with the audio system at 30% volume. I have run it 3-4 hours and it could have played longer. Keeping in mind I have a charging relay that protect the primary battery from discharging below 12 volts. I am running 600 amps 4-channel & 400 amp mono from a single D31M.

Check the Optima chart for your battery’s “reserve minutes” http://www.1st-optima-batteries.com/

[Chexi]

RE: Audio run time

Doh, I meant SC34DM for the dual purpose. Sorry Jaybird, but as always, thanks for the great info.

[AuMDLST]

RE: Audio run time

Here you go Chexi - specs for the optima batteries.

http://www.optimabatteries.com/optim...ical_specs.php

Take a look at these specs - These batteries are the real deal and not overhyped like the Optima

http://www.odysseybatteries.com/battery/pc2250.htm

[AuMDLST]

RE: Audio run time

Here is a good reading link (Originally posted by Mikeski, several years ago in a battery question)

http://www.phrannie.org/battery.html

[Mikeski]

RE: Audio run time

I really hate the guessing game most are forced to place because they don't spend $30 on an inexpensive digital voltmeter. Two wires and done...

http://www.lascarelectronics.com/tem...datalogger=116

The analog dash gauge at the end of the electrical wiring harness tells you very little.

If you don't like the one I use there are tons of other options, in-dash, surface mount, with or without low voltage alarm, even ones you just plug into the accessory outlets.

[01superair]

This is all you need right here, problem solved !