Petscar

Apparently my battery is shot. Called an auto store who installs and they do not do installation on the rx8 as they say say it is too difficult. I looked at it and it seems simple enough. Am i missing something?

Also tried to jump start with a fully charged jumper and got a very weak response trying to start it. I tried 3 times and stopped. Question....would the weak spinning of the engine in an attempt to start have any ill effects on the car? Each attempted start was about 5 seconds.

Go​​​​​ing to try direct jump from another vehicle next.

UnknownJinX

How old is the battery?

That auto store is incompetent. If an RX-8 battery job is too difficult, shut down the damned place and do something else for a living.

Depending on the health of your ignition, you might want to try the de-flood procedures if it still doesn't start with a new battery.

If you have another working car, just pick up a new battery, replace it yourself, and bring back the old one for the core charge.

Petscar

Just bought the car but i think it is 3 years old. It has an aftermarket alarm which kept draining the car but it has since been disconnected. It also has an aftermarket radio which i think drained it this time as it seems it was on.
I want to jump it and get the battery tested before getting another unless there is an issue with jumping from another car. This car is so quirky, i know im being over cautious at every turn, probably needlessly at times.

BigCajun

iTrader: (1)

I'm on my 3rd battery in 6 years.
3 years is not uncommon battery life.
I would be very careful jumping another car.
If you can't take the battery out yourself, consider buying a charger/booster.
They come in handy at times.
I've pocket popped my trunk a few times without realizing it and woke up to a dead battery.

Petscar

The first thing i did was use a charger. It ws fully charged but turned over real s!ow. Tried a different charger...same thing. Tried jumping from another car, same slow turnover. Tried the flood procedure....no luck. Was going to try the de choke procedure but couldnt disconnect the secondary air pump (believe that is what it is called).

Question......why is it turning over so slow? I thought with a fully charged (genius boost) and jump start, it would turn the engine at normal speed.

BigCajun

iTrader: (1)

A charger can't charge a bad battery enough to start it, but a charger/booster can with a separate start feature up to 75 amps.

Petscar

It was a booster. Genius boost 1000 amps. Plus another one from walmart air compressor/jump starter 750 amps. Then i tried jumping with another car. My concern is why my car turned over very slow which i would expect from a weak battery or a not fully charged jumper/booster, but everything was fully charged.

BigCajun

iTrader: (1)

I just read a review of the genius boost 1000 amp and it says it won't start a V8 or "other high performance engines"

BigCajun

iTrader: (1)

Check your terminals are clean and tight.
Meaning they won't move.
The terminals will stretch over time and even thought the bolts are completely tight, the terminals can still be loose.

BigCajun

iTrader: (1)

Mine is electric, when it's switched to the start selection, it hums loudly, and I don't think it ever didn't start my cars or trucks with dead batteries.

Petscar

I will check the terminals. The Genius boost did work once before, but not this time. Kris said he had the same problem once. The only way he could get it started was a new battery.

I looked at batteries. From my research, it seems Optima is the best. Expensive, but is it worth it? They have the red top and yellow top for $50 more claiming it is for high performance engines. I hate to spend $300 on a battery, but will if it is worth the extra $. Your thoughts??

UnknownJinX

Lots of people complain about Optima, it seems. Their QC has declined from what I have read.

That said, an AGM battery is a good choice if you have the extra money. You can shop around for other AGM batteries, preferably one with a good warranty.

BigCajun

iTrader: (1)

I do think you need a battery.
Suggesting a booster was so you could get it somewhere to get a new one if you couldn't DIY.

I get the Advance Auto line, about $130. They have a pro rated warranty.
IIrc, they won't do it with one that was replaced under warranty.
Meaning I paid about $75 for the second one, but full price for the 3rd, but this one is warrantied again.

Be careful with the metal hold down hooks, if those get dropped they're a PITA to retrieve.

Petscar

Yes, that was my intention. I just wanted to be able to get it to the auto store for testing. Im sure i need a new battery. Auto Zone has a Duralast Platinum AGM for $180. I will check out Advance as well. My car currently has a Die Hard. The previous owner had an aftermarket alarm which constantly drained the battery but has since been disconnected. Its my understanding the constant drain shortens battery life. Kris suggested Decker batteries which he uses. I am going to check those out as well.

Steve Dallas

A bad battery becomes a load that will suck current from a booster.

Just buy a $100 battery from whatever auto parts store. Don't waste your money on AGM. Leave the car on a battery tender when not in use. Plan to buy a new battery every 3 years. The engine bay heat kills them quickly in this car. It takes 10 min with a 10mm wrench for a first-timer to replace an RX-8 battery.

Petscar

I dont have a garage and doing a battery tender would be a PIA. Wouldnt an AGM battery hold its charge longer. That is what i thought, thus the reason for looking at AGM's. There are times the car sits for weeks. Is my info correct?

Steve Dallas

AGM batteries are more heat sensitive than lead acid. Not a good choice for an 8, unless you plan to mount it in the trunk. If you do go with AGM, don't buy an Optima. I had 2 of them last about 1 year each in my 8.

wannawankel

I've had excellent luck with Interstate Group 35 batteries from Costco in several cars including my RX-8. Best price evah.

UnknownJinX

Source? Can't find anything that says this particularly. All batteries hate heat.

I went with an AGM because I don't ever want to deal with corroded posts. I will see how long mine lasts.

BigCajun

iTrader: (1)

The felt liners and dielectric grease is all you need.

furansu

Hey Pete,

I agree with others here, avoid AGM designs for the stock engine bay position. I burned through two Optima batteries in 24 months with my FD due to the excessive heat causing them to fail prematurely. Optima batteries used to be (and may still be) very good batteries, in the right application. Buying an Optima or other AGM design will be wasted money on a stock RX-8, leaving you with no added benefits and a higher than average replacement interval for the battery. A good quality traditional lead-acid battery will serve you better and at a lower cost.

Here is the store I mentioned to you by phone, Hensleys Batteries, off Galley and Wooten.
Address: 4865 Galley Rd, Colorado Springs, CO 80915
Phone: 719.573.4663

They carry Deka batteries, by East Penn Manufacturing. I've had nothing but good experiences with them in automotive and industrial battery back-up applications.

REDRX3RX8

You got it down, man.

I only have 35k miles on a 07, and have to disconnect battery all the time.

If you let it sit for more than a week or two, it'll be a little low.

Alternator does seem to perk battery up within an hour of driving, but they all go bad in about 3 years.

The under hood heat makes even the fenders too hot to touch, and is battery killer.

I pray mine dies in 35 months and get a new free one at Walmart next door.

Their batteries are plenty good, and fresh.

Petscar

Thanks for the info guys.

Kris, i checked with them and they have the best price.....$94.

Red, i originally checked Walmart for price. My son who works there says the Ever Start batteries have developed a nickname.....Never Start. 😕

UnknownJinX

I know there is also a dedicated anti-corrosion spray.

Oh well, all moot point for me now. I am willing to be that guinea pig.

I'd imagine an FD's engine bay is even hotter than an 8's, being that it's a turbocharged engine.

My AGM is lasting more than a year and all I am doing for maintenance is a battery maintenance charger once in a while, but then again, it doesn't get Texas-hot here.

All that said, I think OP is better off listening to you since he lives near you, so very similar conditions.

I will say this, however: I doubt a maintenance-free lead-acid will fare much better if you live in a hotter climate. I would at least buy one that you can open and add water every summer.

furansu

I lived in Florida when I owned the FD, not quite but close to the worst conditions you could ask a battery to tolerate. I'm a big fan of AGM batteries and have had success with them in other vehicles, when isolated from the engine compartment. The AGM unit I had in my BMW was showing no issues, even after 5 years, but it was isolated and insulated, with its own compartment in the trunk.

I suggest a Battery Tender for an AGM, or any car battery that goes more than a week between drives. They will maintain a battery state, keeping the cells from building up sulfates or going through unhealthy discharge cycles. I originally got one for my bike, but found it worked so well that I setup the other vehicles to connect to it as well on an as-needed basis.