Which OPTIMA battery to use?

[mountainbiker]

My battery keeps running down. Does that mean I need a new battery?

It might, but then again it might not. The only way to know for sure is to (1) test the condition of the battery to see if it is capable of holding a charge, (2) check the output of the charging system to see if it is functioning properly, and (3) if the battery and charging system are okay, check for a possible current drain on the battery when the key is off. In other words, if the battery is okay and the charging system is doing its job, then something is draining voltage from the battery and running it down when the key is off.

One way to check the battery is to recharge it, then let it sit for a day with both battery cables disconnected. If the battery holds the charge and doesn't run down, it's probably okay, and the problem is in your charging system or wiring.

To see if the charging system is working properly, start the car and turn on the headlights. If the headlights are dim, it indicates the lights are running off the battery and that little or no juice is being produced by the alternator. If the lights get brighter as you rev the engine, it means the alternator is producing some current, but may not be producing enough at idle to keep the battery properly charged. If the lights have normal brightness and don't change intensity as the engine is revved, your charging system is functioning normally.

You can also check the charging system by connecting the leads of a voltmeter to the battery. When the engine starts, the charging voltage should jump to about 14.5 or higher. If the reading doesn't change or rises less than a volt, you have a charging problem that will require further diagnosis.

If the battery and charging system seem to be working normally, the only thing that's left is the electrical system. If the battery runs down overnight or when the vehicle sits for several days, it means something is remaining on and drawing current when the ignition is turned off. It may be a trunk light or cigarette lighter that remains on all the time, a fuel pump relay or other relay with frozen contacts that's drawing current, a rear window defroster that doesn't shut off, or a short in the radio or other electrical accessory.

All vehicles draw a little current from the battery when the key is off to run the clock, keep the memory alive in a digital radio (so it doesn't forget the station settings) and the engine computer. Alarm systems need current to keep their circuits armed as do cellular phones.

Current drain on the battery can be checked with an ammeter. Make sure the ignition is off, then disconnect one of the battery cables. Connect one ammeter lead to the battery and the other to the cable. The normal current drain on most vehicles should be about 25 milliamps or less. If the key-off drain exceeds 100 milliamps, there's an electrical problem that requires further diagnosis.

Finding the hidden current drain can be time consuming. The easiest way to isolate the problem is to pull one fuse at a time from the fuse panel until the ammeter reading drops. This will tell you which circuit is draining the battery. Then you have to check the wiring and each of the components in that circuit to pinpoint the problem.

Source: http://autos.yahoo.com/maintain/repa...ques028_3.html

[JeffW]

I just installed a 34/78 Optima Yellow Top. Although the specs say it is 10" long, it is only 9.5" at the base. And the rounded nature of the cylinders gives even a little more leeway. Each side of the bottom of the battery box has 3 tabs. I only had to trim the rear two on each side to half their width to get the battery in. To secure the battery in the back I replaced the stock trapezoidal piece with the one that comes with the Optima battery.

To make the strap snug, I added a piece of wood to the top of the battery. Two pieces of lattic (the strips used to make/repair lattice fences) were the perfect width and thickness... narrow enough to fit in between the terminal mounds, and not too thick to prevent the top from closing. I glued them together, rounded the ends, and attached to the top of the battery with double-sided tape.

Then to preserve the heat shielding capability, I cut the terminal openings in the battery box lid inward to about an 1/8" into the label. Easy job with a Dremel tool. Fits good, looks good, works good.

[fourfourto]

I was thinking yellow top also .
Do you have the part # of the battery you used ?
Also some pics of install,I want to reuse the top of factory box as I mounted a light to it.

[JeffW]

It should be this one:

http://www.optimabatteries.com/publish/optima/americas0/en/config/product_info/automotive/deep_cycle/spec_sheets.RowPar.0001.ContentPar.0001.ColumnPar. 0005.File.tmp/D34_78_082104.pdf

D34/78, part #: 8014-045

I got it at Costco and I think it is the only Yellow Top they carry.

I will be back under the hood this weekend and double check. I will also try to snap some pics.

From your picture, though, it looks like it might be pretty close. I had to trim to the other side of that plastic stop for the positive terminal, which looks like it would intrude on your light mount.

[fourfourto]

Thanks I wrote info down,so when I eventually get one I have the #.
I think I have almost a inch between the stop and the light.
I could always move light over some if needed.

I havent had any battery problems since 03/06 ,im not running dvd as long without it running also moved 12v fridge relay to a ignition wire.

I would like not to worry about the battery and in the neer future I would like to hook up a winch so the yellow top would work great.

[JeffW]

Sorry for the delay, I was sick all last week. Here are some pics.

[fourfourto]

Thanks for pics, looks tight to fit my light.
Maybe they have one with the posts more apart.
When Im ready I will have to look into it.

[mountainbiker]

Originally Posted by JeffW

Here are some pics.

Hi JeffW,

I see you had to mod the battery box lid. How about the bottom tray--did you have to trim away the little tab/reinforcements (on the terminal / length ends or all around)? Did you mod the "puck" (where the bolt affixes the strap)?

My smaller Red Top with a BCI of 25 didn't require the tabs to be cut, but would have required the lid to be cut (if I reinstalled it). I also had to make a slight mod to the "puck", so the strap would tighten against the smaller battery. Now, I am thinking of upgrading to the Yellow Top. Weird thing is your model has 750CCA, but the same model here in Europe is 690CCA.

mountainbiker