clokker

iTrader: (2)

My last Optima lasted 7 years (and is still going, I assume, with the new owner) and both my parent's cars have sported them for 5 years.
No problems in any case.

Can't (won't, actually) make any claims for increased performance but the reliability has been exemplary.

My5ABaby

iTrader: (7)

When my battery dies I'll get a new/better one. At this point, I'll just save my money and use the battery that's lasted me for ~4 years without any problems (caused by it at least).

Ice_Wolf

Well, I was doing some reading, and it appears to be true that if you drain a dry cell battery, in most cases it will be nearly completely useless since it can't be recharged in the same way a lead-acid battery can be. It said there was one exception to the rule, and that's for a nickel-cadium dry cell battery. If this is the case, I'm leaning away from a dry cell unless it's a nickel-cadium then, because I wouldn't want a $100 battery to be junk if I accidently drained it. My battery in my car now was drained and recharged at least 10 times during the 3 years I had it and still worked up until a week ago. The nice thing about the dry cell is that it can be mounted almost anywhere, obviously making it useful for remote mount setups. Anyone have anything to add about this?

RB_eater

iTrader: (1)

Pretty much any car battery are useless if fully drained once, they're designed to offer maximum output for about 30sec. Deep cycle batteries are designed for steady output and are completly rechargeble. You cant put deep cell batteries in your car obviously but they're good for boats or rv's.

Ice_Wolf

Why couldn't you run a deep cycle battery in your car? I've heard of people running the Optima blue top batteries in their cars before. I understand that any battery loses it's maximum potential to hold a charge when you drain it completely, but apparently dry cell batteries lose much much more than a regular lead-acid battery.

RB_eater

iTrader: (1)

Yes dry cell are more damaged from daining than regular batteries because of their thiner plates. You COULD install a deep cycle battery in your car but it wont have near the same amout of CCAs, they're designed for reserve capacity which is pretty much useless in a car since once the engine runs the alternator prouces all the necessary power.

Ice_Wolf

Yea, that makes sense to not use a deep cycle since you won't get as many CCA, which is very important when starting your car, especially a rotary since they need to be cranked over faster than cylinder engines when starting. Well, obviously I won't be getting a deep cycle battery then unless I could get one that's 600 CCA or more. I'm almost worried about getting a dry cell battery now, because I've had my last battery die on me a few times, and I don't want a 100 dollar paper weight. I'm sure Optima won't replace the battery if I just plain drain it and kill it. Hmm.....

fastrotaries

I'm sporting a Optima Red Top... I love it.

Ice_Wolf

Well, I did some reading on the Optima batteries and what the different colors are for.

Basically, the red top is a starting battery, delivering more CCA than their other batteries but has a smaller reserve capacity. Also, draining this battery and recharging it will reduce it's life more than the yellow or blue top battery. Great for cars that require more power to start them up, like a rotary when it gets flooded.

The yellow top is a deep cycle battery, which means it has a better reserve capacity but doesn't put out as many CCA as the red top does. The other nice thing about the yellow battery is that it can be drained and recharged without losing as much of it's life as a red top. Great for cars that use high power stereo systems but don't require much to get them started, like a 4 cylinder motor.

The blue top is a essentially as red top with different terminal setup for boats, seeing as how it has the same technical specs as a red top. Their terminal design makes them only really useful for boats since a red top is essential the same battery for cars.

takerwolf

Team Kinetiks batteries....
I have had 2 Optima red tops die in 3 years, the latest is now sitting in the corner of my garage and before it died if the car sat more then a week without running it died.
I've only had the Kinetik battery for 6 months but it finally died after sitting for 2 months with the alarm on, but it wasn't all the way dead, just not enough to start.
I went overkill and got the 1800 cranking amp battery but they make a small one too. I think they are made from fiberglass. Learned about them from a friend of a friend who does decibel competitions. Word of warning, measurements do not include top post adapter, I had to end up converting the negative cable to side post to clear the hood. I've only played my stereo for a half hour or so without the car running but it started right up, also left the dome light at work for 8 hours and started right up, then went home and went to bed and woke up, the door wasn't shut all the way so the door lights were on (idiot day I guess) and it started right up.

Ice_Wolf

Well, now that I know the pros and cons of the dry cell and lead-acid battery, I think I'm going to go with the dry cell battery. The only real con to them is that they lose more life then a lead-acid battery when they get drained, but the nice thing is that they last a lot longer, can be mounted almost anywhere, and you don't have to worry about the termnials getting coroded or leaking. Now the hard choice is to go with the red or yellow top. I'm leaning towards the red because I want something that is going to crank the car over fast so it'll fire up quickly instead of cranking slowly and draining the battery. The yellow top is nice if you need the reserve power for a stereo system or extra lighting for the car and it doesn't get hurt as much as the red top if you drain it all the way. If the battery starts getting close to dead, I guess I could just get a quick jump from someone else.

Aaron Cake

iTrader: (1)

This topic hurts me, seriously...

The term "dry cell" is being oddly used here.

In automotive terms, you will use two types of batteries: flooded or AGM. Both are lead acid and none of them are "dry".

Flooded batteries are the typical battery you find in most cars. They contain a liquid electrolyte that sloshes around in the battery and can leak out if the battery is tipped.

AGM batteries have this electrolyte absorbed into a fiberglass mat. Thus they don't contain much free liquid and can be mounted in any position without spilling.

Now, in each of those categories there are both deep cycle and starting batteries.

Starting batteries are the common type that OEMs use. They have lots of thin plates and can produce large currents for a short period of time to start an engine. They don't have much AH capacity so after periods of extended cranking, they will be dead. Because of the thin plates they cannot handle these deep discharges so if you let these batteries go dead their life will be short as the plates easily erode.

Deep cycle batteries have much thicker plates and thicker interconnects, as well as a less reactive electrolyte. This allows them to be deeply discharged hundreds of times, and then recharged without damage. In most cases they cannot supply the huge currents that the starting batteries advertise but they can easily supply the current necessary to start a car. They have higher AH capacities so you get longer cranking periods (for example if the car is flooded). The car's charging system DOES NOT have the proper charge curve and a high enough finish voltage to properly charge a deep cycle battery from dead so if you drain the battery it must be charged externally with a charger that can do it properly. If you don't do this, then the battery will be chronically undercharged and you will get poor life.

To complicate things a bit further, there are "hybrid" batteries that contain some of the characteristics of deep cycle and starting batteries. These are generally marine batteries (ie. Optima Blue Top) that can handle more deep discharges then a starting battery but sill are not a fully deep cycle battery.

Notice I didn't mention CCA once? That's because it's a useless measurement.

Personally I would recommend you stay away from Optima. In the past few years their quality has really gone down the toilet. I've had very good luck with Deka and I run an Intimidator in my RX-7.

Ice_Wolf

Alright, that makes a lot of sense Aaron. I guess there are more pros and cons to the deep cycle or starting battery that I didn't know about. So it sounds like a deep cycle battery would be better for me, since it can handle more cranking than the starter battery, which I will be needing for winter time. Obviously that sucks that you can't jump start it, but jump starting it is going to cut the life of the battery anyways. I did a bit of reading on Optima's website and their biggest yellow top will still give you 750 CCA at 0 degrees F, which is more than what the stock 600 CCA battery is. Also, the 750 CCA is only 50 less than the red top starter battery at 0 degrees F, which is when you need it the most. Think I'd rather be able to crank the car longer with 50 less amps than to get a more powerful start. In terms of deep cycle or starter battery, what would you recommend Aaron?

Aaron Cake

iTrader: (1)

Why can't you jump start it?

You are massively over thinking this...If you don't ever intend on draining the battery dead, use a starter battery. If you intend on draining it dead, then use deep cycle.

Don't buy Optima.

CCA is a basically useless measurement as the methods for measuring it are not strictly followed standards.

RB_eater

iTrader: (1)

I was wondering why you didn't like CCA's lol, I guess if everyone is making their own rulers you cant expect much accuracy...

Ice_Wolf

I was thinking you couldn't jump start it because it wouldn't provide enough power to not hurt the battery or something along those lines. I do intend on draining the battery because I live in -20 degree weather during the winter, and I'm sure a lot of people on here know that sometimes rotaries don't like to start when it's that cold out. I understand where you'll need the starter battery for things that require the high CCA, but I'd imagine a battery that can put out 750 CCA at 0 degrees F should be enough to start the car, even if you need to crank it for extended periods.

Aaron Cake

iTrader: (1)

Like any car, if they are in good tune, the RX-7 will start fine in any weather. -20 is nothing. When I drove my RX-7s in the winter, they were fine during -40 startups.

What you want to end up with is a regular starting battery. AGM is best as it won't corrode your engine bay and is maintenance free. I'm partial to the Deka batteries after having zero luck with Optima over the last few years. The Deka Intimidator is a great battery but not cheap. Exide and Hawker also make excellent batteries.

Ice_Wolf

The reason my doesn't start as easily is because I have the cold start system and BAC removed, plus it doesn't seem like it starts as easy now that I run pre-mix also. I can see about going with the starting battery because you need that extra power during the first 10 seconds you crank the car, and running a dry cell is a good idea too because they last longer if used properly and are maintainance free. But my question is this. Is small bit of extra power during startup going to be worth it over a battery that holds larger charge and can be cranked for longer? Seemed like my problem during the winter was that the battery ran out of juice before I could get the car started, not that it didn't have enough power to turn the car over.

Ice_Wolf

So if you were to use a deep cycle battery and had to jump start it, would you want to hook it up to a battery charger ASAP to get the full charge back out of it then? And is the small extra bit of power during starting going to be worth it over a battery that can hold a bigger charge for extended periods of cranking?

Aaron Cake

iTrader: (1)

If I remember correctly, I'm almost certain I recommended that you not remove these things, especially if you drive in the cold. Without the cold start it's a real pain to drive for those first few minutes, and without the BAC the ECU cannot control the engine idle. No advantage to removing either component.

HOWEVER, removal of these parts will not effect startup. The car should start as before. The real trouble occurs after startup in those first few minutes where the engine needs extra RPM until the fuel properly atomizes and doesn't condense in the intake. Essentially, you broke your car when you removed those components and you want to bandaid it with a battery (which isn't going to work anyway).

Sounds like you are running too much oil and fouling your plugs. Mix it properly, or put the metering oil system back on.

If it takes more then 3 seconds to crank your car, then something is wrong. Instead of posting a HUGE thread about you tuneup, why not actually perform the tuneup?

None of these batteries are dry cell. Flooded batteries will last just as long and modern floodeds are maintenance free. That said, it's still a good idea to buy an AGM battery to avoid possible hassles with spillage.

Buy a normal starting battery, of the AGM type. You'll be fine with anything you buy as long as you don't abuse it.

You would need to properly charge a battery after it is being jumped no matter what type of battery it is. A jump start is an emergency measure. The alternator is not designed to charge a battery from dead and doing so puts a large strain on it. In addition, the alternator's finish voltage is too low to fully charge a battery which has been cycled.

sar

iTrader: (1)

Despite this thread being covered already, I have a couple of random ideas that could help or just be cool to do.

1. If you really have to worry about draining your battery too much to make it decide which battery to purchase based on cycles, consider adding more buzzers to remind you that your lights are off -- or get one of those cool things that shuts off the flow (except starting) when the battery reaches 11.9v.

2. It would be a neat innovation if somebody were to purchase a whole bunch of NIMH cells and super capacitors to replace their battery.

3. It would be even cooler if these super caps / sealed cells were sealed and placed in the hollow rails of the underside of the car. You'd disperse the weight and (if using structural foam to seal) increase the rigidity of your car.

Super capacitors would in theory be able to provide instant energy and be charged back instantly. The practially linear voltage dropoff with the decrease of energy would be a killer though.

RB_eater

iTrader: (1)

As far as MY fc goes, the only ''rails'' I've got are in the front.

A linear voltage drop would indeed be useless.

Ice_Wolf

The reason for removing the cold start was because it was part of the TB mod. The BAC is the only thing that I'm debating about putting back on the car just because if I slam on the brakes it drops the idle down. The car is a pain to drive for the first couple of minutes until it warms up a bit, but once the car is warmed up it drives perfectly. It's not actually driving the car once it's started that's the problem, it's just getting the car to start and fire in the first place. I'm not trying to Bandaid it with a battery, morever I want a battery that's going to suit my purpose.

The ratio I'm running for pre-mix is 1 ounce per gallon of a gas, the recommended mix for regular driving. I figured that maybe when it got cold the pre-mix oil would thicken in the fuel and make is so the car didn't start as easily, but that was just an assumption.

It in fact does take more than 3 seconds to start the car, usually it takes 2 cranks of 5 seconds or so. I've got all my important tune-up things done, but I'm going to go back through and check some of the sensors to make sure they are reading correctly. I think what's happened is that my fuel injectors may be a leaking a bit, because once I installed my fuel pump cutoff switch in the car, it made starting it a lot easier, especially since I could turn the switch on while cranking the engine.

Thanks for the info Aaron. I'm going to be picking up a AGM starting battery then. Is there anyone on the forums that's ever used a deep cycle battery in the RX-7 before?

Aaron Cake

iTrader: (1)

No, it's not. Keeping in mind that the throttle body mod is useless in an NA, you don't need to remove the cold start system at all to remove the secondary throttle plates.

There's another problem somewhere else then, and a battery will not correct that. It's best to find and fix that problem instead of buying a huge battery. Have you run a compression test? How about an injector cleaning?

I don't premix, so I'll have to take your wor for it.

That's a good assumption. It's either going to be an injector issue, or a compression problem if the fuel cut switch starts it.

Loads of people use deep cycle batteries. I have one in my car right now.

RotaMan99

What is your meaning of regular driving? Daily driving? low to mid rpms(idle to 4000rpm) usage? If so, 1oz per gallon is a lot and you don't need that much. 1/2 per gallon is better suited and you can use less then that for light throttle cruise. Unfortunatly, when you premix, you are eliminating the "metering" of the oil which means you have to use a default value that will work for the highest throttle and rpm the engine normally sees.

I use 1/2 per gallon and I rev my engine to the max a few times a week. No ill effects. Remember that 2 stroke is a synthetic and if you get the oil with a high flash point you will have much better lubrication then when injecting motor oil from the pan.

I had an issue with my old engine not starting and I thought the same thing for a little while but then when I did the compression check, I had about 80psi on all faces on both rotors.