I searched the forums but to my surprise I could not find any comments about the type and grade of battery for the RX8.
I have 3 year old OEM battery in my 2004 RX8 AT, and it is struggling to turn the engine over here in the cold North East (18F outside right now).

I chsrged it overnight, but it still was drawing 1-2 amps after 15 hours, so I assume the battery has had it.
Question is, what battery to replace it with - any suggestions ?

Thanks in advance

 

I don't have a lot of experience with such cold weather but I would imagine something with lots of cranking power.

Have you looked into optima red top?

I have a yellow top because of my car stereo upgrade but that weather you deal with is a whole different ball game. Good Luck

 

Yeah, from what I hear and read, Optima batteries are pretty damn good. Personally, I'm a fan of Interstate batteries. I've had one now for about 1.5-2 years and never a problem...matter of fact it was like 19 this a.m., car started up like a champ...no problem at all.

 

get the battery with the highest cranking power that fits snug inside the oem battery box and has the right terminals ..... simple

 

Snug, but still leaving the required air flow space, per the TSB that I linked in the other ongoing "What's the best battery" thread. Heat is a big killer of batteries. It's hot under the RX-8's hood, and the box is designed to allow cooling air flow.

I recommend getting a maintenance free battery. Something I have not been doing for my other cars, since I'm a cheapskate, but I do have a garage and a place to keep a jug of distilled water. And the other cars do not have their batteries buried under covers.

Ken

 

I've always found the Interstate line to be solid as well. My '05 came with an Interstate (the 'cranks but won't start' starter/battery upgrade TSB).

Mine is still good at present, but I may consider the Optima next year as it hits the four year old+ mark.

Max cold cranking amps in the existing box form factor is good advice.

 

i've used optima yellow tops and have had excellent results with them. the red top would be just fine if you are not needing a deep cycle battery.

 

what's the advantage of a deep cycle battery? accessories/stereo equipment?

w/ either optima red or yellow tops, is it a direct drop in replacement or do you need to make modifications?

 

deep cycle is for running bit stereos etc. It can take the abuse of being drained down and recharged better then standard batteries.

 

as for which one fits, here's a thread for the red tops https://www.rx8club.com/showthread.p...ghlight=optima

 

Red Top for RX-8:

http://store.summitracing.com/partde...5&autoview=sku

 

Up until recently I have recommended Optima Yellow top. I consider deep-cycle capability important in this car, even in stock form. It does consume considerable dark current, which will run a battery down in just a few weeks. That will weaken an ordinary battery, even when charged back up. From what I've read, a deep discharge will reduce capacity of an ordinary battery about 25%. Also, deep-cycle do better in a flood-recovery scenario because they maintain voltage further into the discharge.

But, I have read on a few Electric Vehicle threads, some complaints about recent Optima Yellow Top and Blue Top batteries (essentially the same batteries with different posts). The folks who DIY electric car conversions live and die by their battery choices. According to those posts, Optima was taken over by Johnson Controls and the quality suffered. I don't have any first hand knowledge of this; my 3 1/2 year old Optima Yellow Top is doing great. But were I to buy a deep-cycle AGM battery today I might consider the Oddysey brand, which still gets high praise from the EV crowd.

For my money, an AGM battery is always the way to go. Absolutely no mess or maintenance, next to no venting in normal service, and won't leak even if you shoot a bullet into it.

+1 on the dimensions; don't give up cooling for a slightly larger battery. IMO, you're better off getting a top-quality battery that fits per the TSB.

 

Yellow Top for the RX-8:

http://store.summitracing.com/partde...5&autoview=sku

 

$189.95!! For that kind of money you can buy three regular batteries without even shopping for a bargain. Is it going to last three times as long?

Ken

 

yes, mine will last 3 times longer then a standard battery. There NO WAY a regular battery could withstand my stereo system.

 

Check prices; you might have a problem finding a decent battery for $60 these days. The Interstate Battery cold-weather recommendation runs over $135 -- for a "flooded" type battery. Their "Standard" class 35 battery is still over $120. Even their el-cheapo offering is over $100.

So, not 3 times as expensive; more like 50 percent. Will a deep-cycle last 50 percent longer? Imo, it could but that doesn't even matter. I'll probably replace mine at 4 years whether it needs it or not. More important to me that it be trouble-free, I never have to deal with corrosion or maintenance, that it has some guts to get me out a flooded situation, and won't weaken appreciably if deep-discharged. A cheap flooded-type battery might sound like a bargain, but how much does it cost to replace cables and terminals due to corrosion? How much for a tow? For a few more bucks per year I like the peace of mind and total lack of hassles.

 

Yikes! Looks like I've been buying cheap batteries too long. The current battery in my Accord was something like $50 from Advance Auto. About five years ago the Honda dealer told me I needed a new battery, and recommended I go elsewhere because they charged $90 and the service manager thought that was outrageous. ($70 battery I bought then from Merchant's lasted a bit over 4 years.)

I better steel myself for today's (or tomorrow's) prices when Zoomy's battery needs replacement.

Ken

 

FWIW:

"Optima RedTop Starting 12 volt batteries, featuring Spiralcell technology, are designed for all of your starting needs. Vibration and jarring, whether from off-road use or major potholes, can kill a traditional battery. The tightly wound construction in Optima batteries minimizes the plate movement and subsequent damage caused by harsh conditions, extending battery life. These Optima RedTop batteries are leakproof, so they can be mounted anyplace inside a vehicle, in almost any position."

edit: oh, and the Red Top has over 900 cold cranking amps. Very nice for colder climes (and just in case you have to do a longer than normal de-flood start - not that that would ever happen.

 

BRRRWWWARRRR !

Red Top user itz Here ~

Good Battery, a bit expensive. but its not very hard to find good deals online.

I can probably get a Red Top for around 150-160 shipped.

Oh for ur reference, I left my 8 For almost 2 weeks already. b4 I left NYC, I checked the battery's voltage. when I go back I will check it again, just to see how good optima battery is

 

Volts don't generally drop off; it's the capacity that dwindles (amp hours).

 

Anyone tried a 34/78 Optima RedTop? Specs are

RedTop®; Battery; UNBOXED; Group 34/78; Cold Crank Amps 800; Crank Amps 1000; Reserve Capacity 100; Ampere Hour 50; Dual Terminal; L-10 in.; W-6 7/8 in.; H-7 13/16 in.;

The 35 specs are

RedTop®; Battery; UNBOXED; Group 35; Cold Crank Amps 720; Crank Amps 910; Reserve Capacity 90; Ampere Hour 44; Top Terminal; L-9 5/16 in.; W-6 3/4 in.; H-7 5/8 in.;

So the 34/78 is smaller with more juice. Question of fit I guess - and airflow around.

I ask because a friend has one that he can't use and is looking to get rid of cheap.

 

^ smaller would of course work although might require some shimming to preclude it rattling about. Of course make sure the red/black terminals are in the proper orientation so you don't require add'l extender cables.

 

I'd stay with a Group 35, the battery box is designed to allow external air to circulate and cool the battery. The group34/78 is a bit long and will crowd the box. And I'm not sure if the terminals are oriented properly, you'd need to check.

If you'd like a Group35 with even better specs than either of the above, the Sears DieHard Platinum P-5 Group 35 has a 59 amp-hour capacity. It's has the same AGM benefits, has deep-cycle capability and a great warranty.

If you get one of the Optimas, make sure you also get the spacer that's supposed to come with it. The Optimas run short, and the spacer is needed to raise them to the correct height for the stock connectors.

 

Get a battery with a lifetime warranty. You'll never buy another battery again.

 

Thanks guys. Good to see you are still around Nubo. I don't get on here often enough myself.