Help Battery/Startup Issue
 

Before I start, lets just say I apologize for stating anything newbie as I am. :)

So bought my second Z a few months ago. At the time, I had it inspected by a dealership and said battery was low. There was a recall with ignition which they changed out before I bought from private seller.

Then one night at home, like an idiot I left the heated seats on all night and next day. Needless to say it wouldn't start. It had the original OEM battery which I figured should be replaced anyway since it was 6 years old. So I bought the Optima Yellowtop Battery on Amazon. Installed without any issues.

But now it seems hard to start the car. When turning on to acc then on, wont start right away. I have to keep pushing the button over and over and finally it will start. On ac, it shows 12 amps and little under sometimes. Once it starts its up to 14 and over.

Its almost like a short somewhere, maybe from the heated seats? Altnerator potentially? Also note I don't drive it very often at this point as I am waiting for new tires and such, so I just go out for small joy rides.

Any ideas on what to check or what the potential problem is. Connections to battery look good. Maybe I should get the battery checked? Could it be a dud?

Could be a dud yes.reason it bumps to 14v after starting is your alternator is running. I would check the battery with a multimeter and see what voltage it is reading. Have you taken it out on a long drive with the new battery yet? Also you can the leave the heated seats on an they shut off with the car anyway. Old battery was on the way out regardless.

No long drive yet. But sounds like I should? So the lights staying on even with car off still means they are off? I just figured the switch being on meant they were on. So good to know. Will check battery tomorrow. 12.7 is expected right?


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Measure voltage at battery with engine running - should be approximately 14 V.

Take the car for a 1-2 hour trip then check battery voltage with engine off - should be around 13 V. Let car sit overnight and measure battery voltage again - if less than 12 V or so, you have a bad battery or a parasitic drain.

Most electrical items in the car will auto-shutdown after a while when the ignition is off. I don't remember if the seat warmers are on that list but would be very surprised if not. FSM will have more info.

Thanks everyone!!! Checked manual and it states to make sure you turn off if you leave car and states operating when car is off can drain battery..

Taking it for trip today and following your advice. Just hope I didn't get a lemon.


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I just got over this same problem! Optima Yellow top batteries have to be charged with a deep cycle battery charger that's made for agm batteries. I ended up having to replace my battery and haven't had the problem since. I thought I had a draw or a short but it turned out to be a dead cell in the battery. These optimas are tricky batteries to deal with. You'll definitely want to get a charger. I recommend the Schumacher battery charger as its for multiple types of batteries and they're easy to operate

Also once they get drained below 50% their life cycle drops considerably and if you get the charger I told you about then it tells you what percentage the battery is currently at along with the voltage. The Schumacher charger will also jump start a dead battery so they're definitely worth the 80$

Great info!!! Thanks! Will go get one of those chargers.


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dang, on my G (and i think all my previous cars with leather) the heated seats are wired to a switched 12v power relay. the heaters turn off when i turn off the car.

also, yellow tops usually have lower cca vs regular batteries like their red tops. a weaker starter sound is normal. as others posted (or will post), keep your battery charged and float while the car is not in use for longer than a week using a battery tender.

double check that the battery tender supports deep cycle. ever since using these battery managers i stopped using yellow tops.

Probably not a big deal. There aren't that many things that can be the cause of the problem. Most are easy to fix - battery, alternator, regulator, &c. Unless you have exceptionally bad luck, you don't have a lemon on your hands.

Unless you have a specific need for a "racing" battery, I suggest sticking with a plain-Jane OEM-ish Pb-acid battery. With "special" batteries, the weight savings aren't that great (for a DD). If you're going for looks, how often do you have the hood up AND the battery cover off? YMMV

Well took six hours for full charge. Fired right up. Now let's see if tomorrow it's not back down.


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Now it won't kick over. Took for a long drive today! Charger says its at 12.9 but won't start. I hope it's not alternator! Any easy way to figure it out?


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Measure volts at alternator and battery with engine running. If alternator/regulator is working, you should see somewhere around 14.5V.

Find someone that knows a little about charging systems and have them take a look. This sounds like one of those problems that is difficult to troubleshoot via text but would be a snap in person.

Taking battery to get checked to rule it out. Then try to find the drain if battery is good. Thanks!


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If you can get someone to jump start you let it run for a little bit then try remove the ground from the battery. If the car stays on i believe the alternator is fine

FWIW, Optima says the Yellowtop battery is good for "300+ discharge/recharge cycles." I'm not sure how discharged discharged is*, but it doesn't sound like they are long-life batteries - maybe you just need a new battery.

*It also depends on what your definition of is is. snicker

I had AutoZone check my battery and they told me it was goid but it absolutely was not!!! They have to use a tester that's specifically for deep cycle agm batteries and apparently the guy who ran the test didn't know that so be aware of that

Thanks again guys! Taking to autozone now, will make sure they test right


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Question guys, when you push clutch in does the little light telling you to go off? I am wondering if it's that sensor? Or maybe they screwed up the recall. The recall was related to steering lock I think not allowing car to start? Idk just pist as I wanted to run auto cross today!


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I am thinking now it's one of three things since battery is good. Grounding issue, clutch engaged sensor or wheel lock recall was bad.


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Wonder if grounding kit would help? It's 6mt but maybe it helps???


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Possible. Should be reasonably easy to check all the major grounds between the battery and starter.

Going by your post before this one, probable. But you mentioned getting clicks under the hood, so maybe not.

Possible. See comment about clicks above.

The 370Z (and most other modern cars) have very good grounding systems. Yours may need some repair but not replacement.

I had a 7AT, so not familiar with that particular function. User's Manual probably tells you what to expect. If not, the FSM will.

It was the dam clutch sensor! Thanks everyone!


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