[shaun387]

Hey guys, trying to see what the best route for me might be. I have a 2014 Ranger 800 full size. I run a stock battery that also powers an audio head unit that runs two 6.5" speakers. I never have a problem with a weak stock battery. As far as the rest of the bike, I have a stand alone (not being charged via the stator) Optima Blue Top D31M (1125 cranking amps, 75aH) that powers two 1400w amps that push two 12" subs and two Wetsounds Rev10's. That battery will run the amps pretty good for about 3-4 hours with my listening style, then I just recharge it with a battery charger overnight.

Here's my question. Would adding something like the Battery Doctor Isolator be the best solution to get more run time or just replace my stock battery with a larger audio style battery such as the Kinetik HC2400-BLU (1700 cranking amps, 110aH) and do away with the dual setup idea?

I originally thought about doing the isolator, but I do like the simplicity of having just one battery. Is there any math I can do to see what's the best route?

 

[fswan]

Wow - that's a tough one - you're eatin' up some amps! I really don't think you gain much (in this scenario) by going with an isolator. The only advantage I see to an isolator is that it would put your auxiliary into the charging loop. With the typical dual batt/isolator setup, there would not be an advantage to replacing your main with a larger battery because the isolator would not let you use the main to run your accessories anyway (unless you wired some of the accessories to the main and some to the aux). The purpose of isolator is (usually) to 'isolate' the main battery from your auxiliary draws so that you always have a fully charged main to get you home.

You could add an isolator and put your Optima on it as the secondary and your stator would help keep it charged some (extend your amp run time) but I think, without doing the math, you would be draining your aux faster than your stator (42 amps @ 3000 rpm) could recharge it, but I could be wrong. I think, in your case, I would consider running two large standalone, identical, deep cycle batteries in parallel and recharging them manually at the end of the day. That should at least, double your run time.

 

[shaun387]

Thanks for the reply. I guess what I'm trying to figure out is how do you calculate how long a stand alone battery lasts? My stand alone says 1125 cranking amps (don't know if that's important) and it's 75aH. At 100% full load, my amps require 2800w.

I like the idea of adding an additional stand alone (identical), but I'm starting to see way too much extra weight in my bed. I'd really like to calculate how long a single larger battery would last (replacing the stock), running everything (full stereo, amps, Ranger, ect).

Right now, the cheapest thing to do is just add the isolator, keeping the stock battery in place and using the isolator to send any additional charging to the Optima to at least help with the stereo load.

Also, does anyone know about the AGM audio batteries? My Optima is a blue top and I understand it to be rated for full discharge, then recharge and it'll still be fine? Does the AGM audio battery work the same way? Is it okay to completely discharge those?

Sorry for all the questions.....I've never fully understand power demands and how to calculate them in DC systems...

 

[HRTKD]

My AGM battery from Odyssey (PC1700) is OK for discharge. My understanding of lead acid batteries is that if you use them the same way then you are greatly reducing their useful life. I use the PC1700 in my truck. I have an Odyssey PC925 as a secondary battery connected to the main with an isolator. At this time, the only thing I run from the secondary battery is a 9500 lb winch.

 

[fswan]

Thanks for the reply. I guess what I'm trying to figure out is how do you calculate how long a stand alone battery lasts? My stand alone says 1125 cranking amps (don't know if that's important) and it's 75aH. At 100% full load, my amps require 2800w.

I like the idea of adding an additional stand alone (identical), but I'm starting to see way too much extra weight in my bed. I'd really like to calculate how long a single larger battery would last (replacing the stock), running everything (full stereo, amps, Ranger, ect).

Right now, the cheapest thing to do is just add the isolator, keeping the stock battery in place and using the isolator to send any additional charging to the Optima to at least help with the stereo load.

Also, does anyone know about the AGM audio batteries? My Optima is a blue top and I understand it to be rated for full discharge, then recharge and it'll still be fine? Does the AGM audio battery work the same way? Is it okay to completely discharge those?

Sorry for all the questions.....I've never fully understand power demands and how to calculate them in DC systems...

Well, this is going to get real convoluted, real quick! First, if I understand it correctly, your amplifiers do not draw a constant 1400W (1400W/12V=116.7 Amps). I learned that on here about a year or so ago - not sure why they don't, I think it had something to with RMS(???) anyway, it will be less. Hope a stereo guru jumps in here. Step 1 - find out how many total amps your accessories really draw (may need to call the vendors). Step 2 - decide on how many hours you want your stuff to play (without the isolator - we'll add that in later....) Step 3 - do a google search on "Battery Load Calculator" Stop 4 - enter the data from step 1 and 2.

If, in fact, your amps draw a constant 2400W (which I don't think they do) that would be a 233 amp draw. Using the calculator, to run your stuff 1 hour would require a battery with a battery of 768 aH rating for 20 hrs. If you amplifiers draw 300W total (probably a little closer to reality) that figure changes to 84 aH and since you would be feeding 42 amps back into your aux battery via the stator/isolator, you would, of course get some more time... but you are still going run out of juice eventually.

OK, all that is a big ole SWAG (Scientific Wild A$$ Guess) on my part - I sure wouldn't take any of it to the bank - my stereo skills rank right up there with my brain surgery skills! What I would do is call in a stereo expert to help you size your battery - maybe Crutchfield would help you out(?)

As far as your battery type question (I am a bit better at this!) the battery chemistry (Gel, AGM, or Flooded) really doesn't have much to do how much DOD (Depth of Discharge) a battery can handle or how many time it can survive being totally discharged. That is more a question of the batteries architecture; an SLI (Starting, Lighting, Ignition) battery, like the one that came stock in your Ranger, is the most common type. It is designed to give you an initial, high burst of power to start you machine but it doesn't like a high DOD and can only be completely drained a few times before it's toast. At the other end of the spectrum are Deep Cycle batteries. They have thicker lead plates and are designed for high DOD and can be drained many times (your Blue Top is one). Between the SLIs and Deep Cycles are Hybrid batteries that give you the benefits of both (although not to the extreme of either). The Odyssey batteries that most of us use are a such a hybrid - ideal for use in most SXSs (except yours!)

All Odyssey and Optima batteries are AGM (Absorbed Glass Mat). Nice because they don't require any maintenance other than an occasional charge if you let them get low. Gel batteries are about gone off the market being replaced by AGMs. Flooded batteries are the cheap ones - good but require venting and additional fluid (distilled water) from time to time. Your Kinetik HC2400-BLU is an (AGM) SLI, I think. Lots of power but won't like being discharged. Expensive as heck also!

 

[shaun387]

My goodness man, you deserve a beer for that explanation! Okay, I purchased the amps from SonicElectronix.com and they have a pretty good tech support....I'll try to call them on my lunch break today and get real power requirements. I would think, even with letting my stator do some charging, I would never keep up on charging, making the SLI type battery not a good choice. Sounds like my best bet may be to keep the setup I have, and add an isolator to at least aid in keeping the blue top Optima charged while on the trails.

With that idea, I came across the Wirthco Battery Doctor Isolator (Battery Isolator Series - Wirthco Engineering, Inc.). I like the simplicity of this one, and the marine rating, but not exactly sure how it works. All it has is a ground wire connection, main battery connection, and aux battery connection. Seems like it would still have to charge the main while the aux is charging? You seem to know your stuff about this subject. Is there a better type of isolator for what I'm trying to do?

 

[Mrmojorisan]

If you check your manuals for your amps, and sometimes it listed on the box, you should see your rms watt rating for your amp. Even still you may not be using all that power. If you aren't distorting your speakers, check the RMS rating on your speakers. For safety reasons take the higher of the two numbers and use that as your constant draw factor. You can pull a higher draw for a split second but nothing constant. Either way, my bet is it's still going to be a ton of draw for the stator and voltage regulator, but at least you'll be able to know what you're dealing with. If nothing else, post up the manufacturer and model number of your amps and I can see if I can find the info on the interweb.
Here's the risk. By putting that batt in the charging loop, because it will pull such a drastic charge (as I imagine your batt will be pretty low), if it does it frequently enough, you can run the risk of damaging the regulator or stator. I'm not sure the threshold that these stator/regulators can handle. I've seen some go out and I've seen some stand up to all kinds of draw. The simplest way of handling this would be just to add a second deep cycle (and I would make sure both aux batts are the same), keep it disconnected from your charging system and just charge them up like you are doing now. A second aux batt will extend your playing time and by keeping them off the stator will not risk damaging your charging system.
The other option is to hook it up with a separator/isolator and by trial and error see if your charging system will stand up to it. You can look up the cost of a regulator (I imagine they're couple hundred) and see if its worth the risk.

 

[shaun387]

That's a good point. I have seen people talk about over use of the stator / regulator. I'm not sure what the best option for me is. Sounds like the blue top is the best thing for a stand alone battery, since it's rated to be discharged? I hate adding a second stand alone battery, because I'm seeing some massive weight in my bed as it is.

I wonder if using a manual isolator would be a better option? I could switch it to my aux battery for periods I'm not using the amps/subs/wetsounds, and let it charge that way.

 

[DaveB.inVa]

The Diesels come with a full alternator and a battery under the drivers side seat that sits on a tray on the frame. It's only strapped down so eventually the left rear tire threw a rock into mine and busted a hole in it. The factory Diesel battery is bigger than the ones on the 800 but not a common automotive battery.

I took some measurements and fitted a Jegs battery box in the same location that accepts a full size group 24 battery. The group 24 is very common and certainly beats down the factory battery in performance and price.

Here is a link to my writeup, it may help you.

http://www.prcforum.com/forum/17-ranger-discussions/49788-diesel-battery-box-install.html


There is also an alternator install for the 800 that you may be interested in. If you go all out, you could run two separate systems. The add on alternator running your audio to a separately mounted battery and the stock stator system for everything else.

Ranger 800 Alternator Kit Free Shipping | RPM Off Road Fabrication | Metal Fab Work

 

[shaun387]

You guys have made some good points. With all the brainstorming, I think I come up with a solution. My '14 model has a pretty good size battery under the drivers seat. I think I might swap that out to another Optima and power the amp that runs my wetsounds off it as well.....then just power my amp that runs the subs with the stand alone optima. Not sure why I didn't think of that before, but I'm leaning that way now. Seem like an okay idea?

 

[Limo driver]

Forde, your knowledge and understanding of electrical systems is second to none and quite honestly blows me away! I used to think I had a decent working understanding of electrical systems until I joined this forum. I am confident I am speaking for many members when I say "thanks" for the time you take to help us.

 

[fswan]

Thanks Fred, but I'm no electrician, just a curious old hermit with nothing better to do than research the internet. The real 'Thanks' belong to guys like Jerry, Curt, Neal, Allen, Kris, David, Mark, Todd (Teshreve), Greg, Allan, WagZ, Josh, and SO VERY MANY others that have a passion for our sport and a willingness to share their knowledge and experiences unselfishly with the rest of us!