98 z/28 charging battery

**LETHALxLS1** · 02-14-2013, 10:37 PM

Is it ok to charge the battery with it connected to the car or should I disconnect the + and - before charging?

I don't want to mess up the CPU or anything so I figured its best to ask. In the past I always disconnected it first but........

**pajeff02** · 02-15-2013, 03:39 AM

A modern charger shouldn't cause any harm, especially if it is a trickle charger. I use mine all the time over the winter months on a couple of cars.

**konigandy6** · 02-15-2013, 05:26 AM

What Jeff said.

**SiggyZ** · 02-15-2013, 11:41 AM

What's a good trickle charger I can get for my car when it sits for awhile?

Originally Posted by pajeff02

A modern charger shouldn't cause any harm, especially if it is a trickle charger. I use mine all the time over the winter months on a couple of cars.

**pajeff02** · 02-16-2013, 03:47 AM

The Deltran units that go by the "Battery Tender" moniker all work great and are reasonably priced. I have a Stanley trickle charger I use on the Monte Carlo battery, however, the charging level light quit working on it after only a couple of months.

**KMdef9** · 02-19-2013, 09:06 AM

I use Schumacher. Has microprocessors to monitor/maintain the charge.

**35th-ANV-SS** · 02-19-2013, 05:48 PM

I just got a Deltran Battery Tender. Haven't used it yet though. Came with a 10-yr warranty so I assume it's pretty good.

**doncooke** · 02-20-2013, 11:52 AM

I've used a Battery Tender Junior for years on MC's and my Camaro every winter and never unhooked the battery. No problems at all.

D

**LETHALxLS1** · 02-20-2013, 09:59 PM

I bought a die hard charger from Sears cause I am such a sucker for brand loyalty......we shall see if it lives up to the name.

**LETHALxLS1** · 02-20-2013, 10:09 PM

Oh and fk it..... I will continue to unhook the + and - just to be safe. Last week I went out and tried to start my Z and I could tell the batt. Was pretty low so I gave it a little gas and it started immediately.

BUT- it reved up to 3,000rpm and then down to a 1000 back and forth like it didn't know what RPM to idle at. I gave it a quick rev and it stayed at 3000rpm so I turned it off. I started her again (this time I didn't pat the gas at all) and it idled perfect.

I have never gave this car any gas when starting it because it doesn't need it (it being a elect fuel pump and fuel injected). I believe the battery was so dead the computer had to reset itself and me giving her a lil gas at startup maybe confused the computer?

I am not sure........any ideas why the car did that? I know I will be keepin my batt charged from here on out.

**pajeff02** · 02-21-2013, 03:29 AM

It doesn't take much to keep the PCM's memory intact -- there are kits that utilize a 9 volt battery plugged in through the cigarette lighter to keep it from losing its marbles. That being said, our cars clearly do not like a low battery and do all sorts of weird things when you try to run them that way. Our car has a draw and will kill the battery after a few weeks unless I disconnect it. When it is run down and I start it, the engine stumbles and acts weird for about the first minute and then things seem to settle in.

**sjgreen6** · 02-24-2013, 05:42 AM

As several have suggested a "modern" battery maintainer can do wonders for the longevity of your battery. There is however an important difference between a trickle charger and a battery maintainer that you need to understand. A old style trickle charger puts out a constant flow of voltage to your batter at a specified amperage level. These things are fine if you just plan on doing an overnight charge to bring a battery up to capacity before use. However, the classic trickle charger does not know when you battery has had too much and can shorten the life of your battery by overcharging.

A modern battery maintainer like the Deltran Battery Tender has several features that you want when used with a car in storage. The maintainer reads the battery voltage and only charges when the battery is below a certain level. Most maintainers have a protection circuit so if you hook it up backwards it will not charge. Many maintainers also conduct a charging cycle that intentionally allows a battery to drain down a bit before charging back up to "exercise" the battery and extend its life. You can use a maintainer on the battery while it is hooked to the car without causing damage to your vehicle.

Personally I use Deltran maintainers on my car, motorcycles, and lawn tractor and have found they they pay for themselves by extending the life of the battery to more than double in some cases.

**LETHALxLS1** · 02-25-2013, 01:02 AM

I think the maintainer you speak of might be the best option for me right now because I have some health problems and the car will be stored for a while. I already put Sta-bil in a fresh tank of the best gas I could get.

Thanks for the link on the Deltran. Do you use the one in the link you gave for your car? Thanks

**sjgreen6** · 02-28-2013, 12:48 PM

Actually I just typed in the words and the computer added a link. The Deltran Battery Tender Junior is pretty much the gold standard for these maintainers and will work well on an auto, motorcycle, or lawnmower battery. You can get them on line or at many local auto parts stores. You won't be disappointed.

**GoldenFlame** · 02-28-2013, 02:10 PM

Originally Posted by LETHALxLS1

Oh and fk it..... I will continue to unhook the + and - just to be safe. Last week I went out and tried to start my Z and I could tell the batt. Was pretty low so I gave it a little gas and it started immediately.

BUT- it reved up to 3,000rpm and then down to a 1000 back and forth like it didn't know what RPM to idle at. I gave it a quick rev and it stayed at 3000rpm so I turned it off. I started her again (this time I didn't pat the gas at all) and it idled perfect.

I have never gave this car any gas when starting it because it doesn't need it (it being a elect fuel pump and fuel injected). I believe the battery was so dead the computer had to reset itself and me giving her a lil gas at startup maybe confused the computer?

I am not sure........any ideas why the car did that? I know I will be keepin my batt charged from here on out.

I've had that happen before. Starts then kinda dies, but you give it gas and it goes, but runs like crap.. Idk why, when you restart the car its fine. I need a new battery soon, mines 7 years old and my trip odometer won't stay anymore, and the gauges sweep at start-up. Not sure on battery tenders, my Camaro is the DD and I take my vette battery out during the winter.

**2002ssslp** · 02-28-2013, 06:01 PM

Originally Posted by LETHALxLS1

Is it ok to charge the battery with it connected to the car or should I disconnect the + and - before charging?

I don't want to mess up the CPU or anything so I figured its best to ask. In the past I always disconnected it first but........

Just use your charger on automatic and do not go over 10 amps.

**LETHALxLS1** · 03-04-2013, 12:32 AM

Originally Posted by sjgreen6

Actually I just typed in the words and the computer added a link. The Deltran Battery Tender Junior is pretty much the gold standard for these maintainers and will work well on an auto, motorcycle, or lawnmower battery. You can get them on line or at many local auto parts stores. You won't be disappointed.

Thanks!