Hi,

I have a 2003 G35 Sedan that doesn't get driven very often. It has only 46,000KMs after almost 7 years of ownership.

I currently have a dead battery problem - the car won't start without a boost. The thing is, I had the same problem a few years ago, and the dealership charged us to put in a brand new battery. Given that it has only been 2 or 3 years since the last battery replacement, and since the car doesn't get driven too much, I'm wondering if it is normal to have to replace the battery every few years, or if there could be an electrical or alternator problem that is draining the battery. I'm also wondering if the fact that the car does not get driven very much could have an effect on the battery.

Any ideas? Suggestions?

Oh, and in case you're wondering, the reason for the low KMs is that I work from home so don't drive much, and my wife has a Nissan Altima company car with free gas and maintenance, so we baby the G35.

 

Car batteries aren't meant to sit for long periods of time. When you drive they get charged up.

If this is how you use the car, you might look into a battery tender or an Optima deep cycle battery that can be charged up when it gets run down.

 

Car batteries are designed to last "X" number of months which is usually printed on the battery. My experience is that under normal usage they have the expected life down to a science and usually only a few months longer than their rated life.

 

My battery (Die Hard Platinum - gel cell) is a 5 yr battery.

Most are between 4-5 years

 

I looked into it and the battery was last replaced in May 2008. The doesn't seem like very long to need a new battery already. Would you think it's because the car doesn't get driven enough, or, would you think that maybe there is something wrong that is killing the battery?

Thanks

 

Typically 5 years.

But, how long does the car sit between periods of driving. If you are going 2-3 weeks routinely, then it could be why the batt may be dying prematurely. You may want to look into hooking a battery tender up during the down time.

Only way to see if there is an issue with the car is to hook a DMM in series to the batt and measure DC Amps and see how much current the car pulls at idle rest. Could have a short in the wiring somewhere

 

The secret to getting the Maximum life from a lead/acid battery is to keep it fully charged. To make electricty the lead in the plates reacts with sulfuric acic to form lead sufate. This reaction is reversed when the battery is charged. Lead sufate is not real soluble in acid so it has a tendancy to precipitate out and collect at the bottom of the cells. The problem is that left long enough the lead sulfate changes crystal stucture to one that will not be redissolved on charging. When eough builds up it will short out the plates in the battery cell. Result- dead battery.

Like the others say- get a battery tender. It works great on my motorcycle battery.

 

Thanks for all the advice everyone. The car is in the shop right now getting a new battery put in. I think we'll just make a point to take the car out more often. I'll make sure I run it to the store at least once a week.

 

If you run to the store weekly, make sure the run is at least 10-15 miles, otherwise you'll create condensation problems. During a short trip, your car’s engine is unable to reach its full operating temperature. Water/condensation is a byproduct of engine combustion and is usually blown out thru the tailpipe or the crankcase ventilation system; however, if your trips are too short and the engine doesn't really heat up for a period, this condensation/liquid stays in your exhaust and crankcase, which begins to corrode quickly.

In addition, this left over condensation and water can dilute your oil. I've long believed that it isn't always the mileage or distance that a car travels that causes the most wear to your oil, but the number of times one starts the car -- this is where the lion's share of unburned gas seepage and condensation enters your oil. Others will likely debate this, but it seems fairly logical.

 

typically 4 years for the G's OEM battery.

 

Really appreciate this advice. Thanks!

 

Lots of variables.

In south Texas, you were lucky to get three years out of one - the heat shortened their lives considerably.

Up here in Washington, my G battery is finishing up it's 5th year, and there's no sign it's giving up the ghost any time soon.

 

Battery Tender or trickle chargers are as cheap as $20. Just buy one. You could have saved yourself a new battery and the shop costs right there.

 

Odd. For the last four years, my daily commute has been ~7 miles. I have my car on a lift at least 4 times a year, and haven't seen any signs of wear on the exhaust system... It may be rusting from the inside out, but by now, especially considering the bulk of my car's life has been in rainy Washington state, I'd have some visual indication that the short trips were having a negative impact.

I change my oil every 3-5000 miles with Mobil 1. Usually closer to 3,000, but no one is perfect. Car only has 29,000 miles - it's an 05.

 

It's not so much the exhaust and undercarriage that you need to worry about as it is the engine oil and engine/trans internals.

Frequent engine starts and stops and short commutes put more wear on the engine than 100K+ miles of strictly highway driving. That's why oil change intervals are usually closer together vs a car driven on the highway. Proper operating temp isn't achieved in short drives. The coolant may say the car is warm, but the oil temp may not be.

But there isn't much you can do really other than drive around more.

IMHO, cars should come with an hours meter and you do the oil changes based on start/stops and hours run vs actual vehicle mileage.

But....so MANY variables such as humidity in the air, climate, etc.