HEre is one I wanted to throw out there. Ever since I moved my battery to the bin behind the driver, I have had a problem with it keeping a charge (mitate small battery). I have gone through 3 in 3 years and when it was in at rotary performance I had them try to track it down. I ended up just putting a battery tender on it to keep the charge. Even though I only drive it once or twice a week, it just puzzles me that I have to keep putting them on a charger. That bin is pretty low to the ground, so like I said I wanted to throw it out there and see if anyone else had this problem before.

 

funny you mention this, i thought i was alone on this. I have gone through 2 batteries already. im sure the one i have now is toast with my luck. car has been sitting for a while due to a swap. I had the original miata battery in the engine bay first with never an issue so its not like its not up to the tasks...it has to be some sort of oversight on my part, maybe in the wiring or something somewhere because it doesnt make sense how location would cause this behavior.

 

I went through 5 batteries in 1 year miata batteries , THen I changed my alternator and haven't had an issue since

 

I should have mentioned that. I also put on a new alternator about a year ago.

 

Do an ignition off draw.... If it has a draw pull fuses until it goes to normal. Check your grounds etc....

 

My car has the battery in the back and it dies in 2 days! It's on my need to fix list, PO was a little creative with electrical work. I have only had it about 2 weeks. I don't see how the battery's location could have much to do with the discharge rate, bad wiring is bad wiring.

 

I bought a Honda civic battery, optima yellow top. It solved my problem of battery dying. I can tell after sitting a few days it cranks slower, but it had never died. Now my previous battery would only last 2 days without running before being a jump.

There are guys on here that actually put a full size battery back there. They remove the bins to get it in. It's a bit of work, but you'd plenty have of power for parking the car for a while.

 

you guys need to check for drains. on the battery

 

You guys know you can get a battery tender for like $30 shipped on eBay. It comes with two cables - one with clips and one with terminals. Hook up the one with terminals to the battery and run the cable to an easily accessible spot. If you're not going to drive the car for a few days or more, just plug it in and leave it...

 

If it dies in a couple of days then something else is draining the battery, a relocation should not cause a battery to die if it was done right. I relocated my battery to the end of the trunk in my MX-6 for a good 5 years, car always crank strong and it held charge even after it was sitting for a few months.

 

I agree, but it could be that some people are using crappy batteries. Also it's winter weather right now...colder temps, harder starts...

All that being said, I had a smaller sized optima yellow top relocated to my passenger bin. Never had any draining problems, even without a battery tender.

 

I don't feel it is a draw so much as it is the loss of size of the battery. The OEM battery is the same size as my 4runner battery. Think of how much battery you lose by putting a small one in the storage compartment. With that, some sacrifices need to be made. Battery longevity seem to be the glaring issue with the battery down size. Plus the rotary engine is a hog to start.

 

Physical size of the battery should not matter, as long as the cranking amp and charging characteristic is up to spec in warm/cold weather then it should perform just like our stock battery in stock location. You might not get as many crank as you can out of a stock battery, but you shouldn't have to crank it more than once to get it started

 

As menchioned earlier, you guys need to to do a current draw test on the electrical. The factory spec is .20 amps or less with everything of.

All you have to do is disconnect the positive cable and in install a multimeter in between the battery post and cable.

1st make sure everything is off on the vehicle (doors closed ect). Set your meter to the amp/current reading. Then put the meters positive plug into the 10amp max fuse port on the meter. Leave the negative plug in it's normal spot. Now that your meter is setup, remove the positive cable from your battery. Attatch the negative lead of the meter to the positive post. Take the other postive lead of the meter and attatch it to the loose positive cable.

This completes the circuit so all the current goes through the meter. You should be seeing .20 amps or less on the meter if everything is off. Anything higher than this will slowly drain your battery. Start pulling fuses to see when the current drops. That's how you isolate a nagging current draw. Also don't forget to check the alternator. That was my personal problem. Sometimes the internal voltage regulator will screw up and put a draw on your battery so pulling all the fuses didn't isolate my problem because the alternator is direct to the battery. After I disconnected the positive alternator lead, sure enough my current finally droped to .20.

Lastly be carefull of what you turn on because the meter can only handle 10amps of current going through it. Any more than that and you will blow the internal fuse to your meter.

 

Mine was dying since I only drive it a few times a month, bought a quick disconnect for 2$ and dont have that issue anymore. Also works as an anti-theft device when they dont know where your battery is located

 

I have a Miata battery installed where batteries go, in the engine bay. Car routinely sits for WEEKS, I can hop it, crank up, and go.

Most times relocated batteries just don't work right, not sure if it's the wiring, the grounds, what. I prefer keeping it under the hood, there isn't enough damn space in the passenger compartment as it is.

And, having to wrestle around with a battery in the storage bin in cars I've worked on has sworn me off that foolishness.

Dale

 

I went through lots of batteries too with mine in the back, even yellow and red top full size batteries, didn't know why, so I just put on the battery a quick disconnect from advance auto, quick and easy and then it cranks real good.

 

Curious, what gauge wire are you guys using on your relocations? I use the thick 00 ground cable from most welding machines that I bought at airgas. Also, where are you guys grounding? My ground 1st goes from the battery to the lower seat rail mount bolt on the floor pan then up through the shifter were it bolts to the back of the transmission to ground the engine. Remember guys a proper battery ground is a single loop (battery, chassis, and engine in series). Not split up!

 

I usee the kit from rotary performance, hooked to the srarter and the frame. I changed their reccommended to the strut tower after several discharges. Seemed to help a little.

 

You can also check voltage / current to the battery while the car is running to see if it is really being charge, and how effective it is being charge.

 

Any chance you can post up details on why it should be done like this? I'm about to run my grounds (0 gauge) and would like to understand it before I do it.

 

That's standard practice with how manufactures ground their vehicles (fd included). All those other threads you see with upgraded hyper ground systems (aka excessive numerious ground wires all over the place) are complete nonsense. You can add 50,000 grounds to your vehicle and it's not gonna improve anything if the MAIN battery to chassis to engine ground isn't correct. That's why I use the thick stuff.

 

That's good to know before I do my relocation this spring.