I will have to agree that I have never heard anything bad about Kinetik batteries. I know plenty of people that run them as a car battery as well with no probs, I need to swap my Optima out for Kinetik actually. I used Optima a few years ago when Kinetik was just starting and I was not too sure about them, And now that I have gone threw prob like 5 replacement Optima batteries I wish I had gone with Kinetik when I had the chance to get them at the sound shop I was working at back then. As a matter of a fact I have another dead yellow top in one of my xBs right now, cause I did not drive it for a week.

 

well if ya need a Kinetik or any other car audio/video/security need then hit me up. we will ship to your door!

 

Winter, thank you, you seem to be one of the few people who understand this problem. I'll try and reiterate it though.

I am not looking for a battery that can handle high current draw. My system would only be using about 1200W Max, and this would be with everything full volume, both displays on, etc.

My issue is that, in a 24 hour period, the car is only running for about 30-45 minutes, which is the only time the battery is charging. For the other 23 hours, there is a Mac mini carputer sitting in sleep mode, but still on, drawing a smaller but unknown ammount of current. The power draw over 24 hours is greater than the charge capacity for the 30-45 minutes, resulting in a dead battery over two weeks or so unless an external charger is used. Here are the possible solutions, pro's and cons:

1) Bigger alternator
A larger capacity alternator will increase the charge capacity of the system, hopefully recharging it enough during that 30-45 minutes to sustain the other 23 hours of battery drain.

Pros: Self sustaining, easy to install
Cons: Expensive, if charge is still less than draw over time will not work


2) Bigger battery
A larger battery will allow for the car to hold more charge, running for longer before being depleted.

Pros: Cheaper, easy to install
Cons: Only delays the battery dying, not fixing it. Will still need to periodically be externally charged


3) Second battery w/ relay to de-couple when car is off
Uses a second battery that will charge from the alternator when the car is on, then disconnect from the main battery when the car is off and only power the computer.

Pros: Will not drain the main battery, car will always be able to start
Cons: Secondary battery will need external charging, will shut down computer when drained.

The question about amp hours is an easy one to answer. It's a measure of battery capacity, saying that for one hour, the battery can continuously give out the rated number of amps. At the end of that hour, it will be fully discharged. The bigger the number, the more storage capacity a battery has. If the Optima and Kinetik both have a 60 A-h rating, they have the same capacity. Drawing 60 Amps continuous will kill both of them in one hour. If Kinetik has a 1500 A continuous rating, it's pretty useless unless you're really drawing that much power, which for speakers would be around 18,000 Watts. With a 60 A-h rating, drawing 1500 amps would kill the battery in 2.4 minutes. Max continuous output is affected by internal resistance, which causes heat buildup.

BTW, Kinetik isn't a "dry" cell. It's a sealed lead acid battery (SLAB) that happens to use a fiberglass separator to retain the acid electrolyte between lead cathode and anodes. This is the same type of battery used for flight applications because of thermal and physical shock resistance and multi-axis orientation capability. A true dry cell uses an electrolytic film, is usually basic (high pH) and not a suspended acid. I do have to call BS on Kinetik when they go into the load balancing thing. Kinetik is in the business of selling batteries, it would only be natural for them to say "for best performance, only use Kinetik in multi-battery setups". Current reflow is really a function of the different battery capacities and interconnect wiring resistance and is brand independant.

For high current draw, SPL applications, I'd go with Kinetik, Batt-cap or another SLAB battery. However, I need high capacity, low current draw so I'll be going with the cheapest battery with the most A-h.

 

i promise you, that huge crank rating they use is NOT continuous. you try running 1,500amps continuous for 15 minutes, not going to happen... 15 seconds maybe... after that, it's dead. a wet cell can do, lets say a theoretical 450amps and 15 seconds... after that, it's NOT dead due to the liquid cell design. the chemical acid discharge INSIDE the battery slowly recharges it's self back to it's stable voltage, a dry cell does not have this, making it less reliable in a needed environment. imagine your self in a winter storm... you're stuck, your engine doesn't seem to want to start. you keep turning the key hoping it'll finally pickup and get you home safely. a wet cell will be your life saver here, a dry cell... you're screwed. this is where GEL cell batteries come into play. they carry higher power capabilities, they have a liquid gel acid base that helps keep it's voltage stability under a continuous heavy load. GEL cell's were designed to be an upgrade to that of wet cells for industrial purposes where a quick charge is needed and longevity is wanted. a dry cell wont give you this. dry cells are only good for racing and secondary battery addons for power buffering, they are NOT good as a main battery. the one time that Toyota's reputation fails you and you have a dry cell and it's one of those times that simply cranking over and over is needed... that dry cell will fail WAY before you get that lucky start...

your vehicle will only stay as reliable as you let it be. fail one time and it may be something that will put you in a dangerous situation...

use a Gel cell for the main and a dry cell for auxiliary, it doesn't get any better than that.





Vettereddie - If you use an upgrade alternator from Iraggi, you'll still have toyota's rep on that sucker. i don't know what it is that he does, but his alternators are rock solid. i wouldn't touch alot of the aftermarket ones due to possible repair issues and continuous failures. getting a secondary battery is a good idea, but like you said, you will still continue to have the same problem after a while.

what you need to do is this. tally up the max draw of all the continuous draw items such as your displays, gaming systems and whatnot. add the wattage up. and then when it comes to your sound system, take the total true RMS power of everything and subtract roughly 40% off of that for an average ACTUAL power usage. then add the two together and you'll have the continuous wattage draw. take that result and divide that by 13.8 *13.8volt* which will give you your average total amp draw. from there, you can accommodate the proper alternator over stock so you don't go too over board, you can also help match what auxiliary batteries you'd like to use for the setup aswell.

 

Yeah, I thought of doing all the calculations, but think I'm instead going to try and get a hall effect sensor from work and hook it to a data logger. When the car is off, the current draw should be consistant, and when it's on, it's always the same stuff, Mac Mini, 7" Touchscreen, stereo at 15 (out of 30 I think), both amps. I should be able to get a decent average after 6-10 minutes. For now I think I'll just power the PC off of a second battery, coupled via relay so when the car is off it's not connected to the main one under the hood. I'll plug in the secondary once a week to keep it charged.

 

your main concern should be your "off" time current draw. that's the bad zone and don't want that happening when you've got your self parked for the night. you'd be starting your morning with alot of frustration

 

I 3rd nodsetse and speedshop's suggestion.

2nd small dedicated battery for computer memory, isolated from primary when ignition off and charged when ignition on. Its really the best choice if you want to be able to start the car reliably.

 

i'm not going to argue over and over. a Kinetik HC1400 would work forever and a day w/o problem. but i aint going to BS about what is better because i know from experience what is what and what will work for the lifetime of a vechicle.

 

umm... if your tryin to figure out what your Current/amp draw is while the car is off and the mini-mac is "sleeping" wouldnt a "amp clamp" or other current measuring device do the trick?
doesnt solve your prob, but puts ya a step closer

 

Yes, it would, if you see my post above, the "amp clamp" is a Hall Effect sensor. Now I'm just trying to either find a cheap one or be able to borrow one from work.

 

http://www.batterybrain.com/batterybrain.pl

 

Nice link, but hella overpriced.

I was reading up on the DC-DC supply I'm using to power the Mac, it looks like I need to do a reflash of the firmware. It's a Carnetix P1900, found here:

http://www.carnetix.com/CNXP1900.htm

They state:
I think #2 is my problem. It still won't solve the problem of needing to recharge the battery periodically, but at least it will keep me from having to jump it from a portable unit. I'm currently using this when it dies:

http://www.blackanddecker.com/Produc...roductID=15581

 

ah... yeah.. saw that... for some reason my brain interpretid that as being more involved than just putting clamp on one lead or the other and reading the display,

anywho... try goin to sears? think i saw their tool catalog have some in the low $100s... and if you keep it clean enough and dont destroy the packaging, could always try and return it as a duplicate gift or something... just a thought

 

do big 3 first

 

Well, I flashed the power supply but I think it's too late for my battery, it will only hold a charge for 2-3 days now and will def. need replacement.

I'm looking to go with an Odyssey PC1400, just need to find the right price. Still looking into the alternator upgrade, that + reflashed DC/DC convertor should = no need to recharge. I'll be doing the big three as well, not sure if it will matter on a low current, high duration application, but I already have the wire and terminals.

 

Years ago I had a problem keeping a small battery charged that ran some electrical equipment in a van. Similar to your problem.

I found a solar battery charger in the system to keep the small drain of the equipment was a cheap easy fix. They make them to keep batteries charged in motor homes and the like.

You could try one to see if it kept the battery up while it wasn' t running.

It kept my video and audio equipment up and running 24 hrs a day and I could start the van and leave.

 

The diode solution is surprisingly easy, and the voltage difference is not that big a deal. I bought something like this at an auto parts store:

http://www.northerntool.com/webapp/w...2955_200342955
Here's the manual:
http://www.northerntool.com/download...als/171213.pdf
$25 or so for the isolator, buy a decent gel-cell battery, get a dc breaker, run the computer off the second battery - when the car is on, both batteries are getting charged, and your cpu is running. When you turn off the car, the diode blocks the current drain on one battery from the other, so your car can start. And yes, they are very different kinds of batteries. I use one at home to keep my ham radio battery charged, if the power goes out I dont hurt my nice power supply.
You're right that the inverter is eating some power, but as you've found, the mac mini is not made for a dc-dc PS. You could possibly add a small UPS that could tell the cpu to shut down. Also, I dont have a mac, but it might have a sleep mode that copies the ram to the hard drive, so a startup puts you back where you were.

 

This problem has been fixed for a while now. Not sure what the exact cause of death of the old battery was, but swapping it with a new Stinger SP1000. I haven't had to charge it or have it die since.

http://www.stingerelectronics.com/pr...=35&ParentID=1