Scott. you should move that red one that is doing nothing. Im sure you could find a place within reach. It would only take a few min.

Yeah I plan on doing that at lunch.

I removed the harness so teh factory block ground meets the battery relocation wire at my terminal...like so

Attachment 227600

Yea i left those dinky wires there as well, had a starting issue. Took a short run of the radaflex from the chassis, fed behind the pullies, and up to one of the water pump bolts, and that did the trick for me.

I have a single ground in the trunk from the battery to the shock tower brace stud and then also added a ground from the chassis to the engine

with the new starter my engine fires off so fast I don't even get to hear the starter turn over

I'm sure the warm climate helps, but I will get a clip and post here, i was expecting my starter to crank the engine over a bit quicker since i replaced the battery in the trunk with a 900cca diehard platinum (dirt cheap on sale from searz woot) to replace my AGM battery that wasn't just cutting it for DD reliability.

it was 40 degF and the engine hadn't been started for almost three months prior

I do have a mega CCA Li battery rather than one of the usual AGM racing type

.

Mark dose the Lithium Ion battery have any extra considerations with the charging system?

Oh lol, well then. This is what my lady sounds like starting up after work. 46F outside ... sitting for 8 hours ... sounds a bit weak no?


Nah, no Li battery. I just went with this for the sake of having a nice strong battery

DieHard Platinum Battery : Buy High-Performance Battery at Sears

My dad has a few Jeeps and he used the AGM's (optima) for a while but swears buy the Die Hard platinum now.

But I did find this review :)

Not the one I bought. Most don't, but there are a few. It depends on the electrical control board package they use, or whether they actually have one or not.

It has 4x more CA, 2.5x more reserve, and 33% less weight than a Odyssey PC680, but be forewarned that I got a good deal it was still 15x more $$$

if you go with an Odyssey etc. then for street duty I wouldn't recommend anything smaller than the PC925, but its almost 2x the weight of a PC680. The equivalent size would also be good for a street driven Li battery, but again you have to pay to play. The Li version would probably only weigh around 8 lbs.


.

lol well mine wont fit in the battery box either :yelrotflm

platinum? dont have those here....

Do have Odyssey Batteries though...

DieHard Platinum / Odyssey / Enersys are all the same thing.
EnerSys Signs Multi-Year Contract to Provide Sears Holdings... -- re> READING, Pa. and HOFFMAN ESTATES, Ill., Feb. 27 /PRNewswire-FirstCall/ --

Grounding from engine to chassis made no difference. I am going to go from the battery in the trunk all the way up front and see if it makes a difference. If not then I will put the battery up front to insure it is not something else causing the long cranking times.

silly question, but exactly what did you ground the battery to in the trunk.

btw, no one answered, my cranking, normal even for a 900CCA battery?

It is grounded to an existing ground that was already there and to one of the shock bolts.

must be the color of your car

No, if that were the case it would start faster than any other color.

Do not use any shock bolts as an earth point, they are very poor points to use as an earth, as there is movement and over time can work loose.
If you are going to mount your battery in the boot, which is a good place to put a battery, due to it being far away from heat. Batteries do not like being in a hot eviroment.
Also if you mount the battery in the right place in the boot, it can help with better weight distribution. But dont mount the battery all the way in the back of the boot, as this then just becomes a swinging weight, the further to the rear of the car that you mount it. Mount it as close to the back of the rear seat as possible and run an earth point down to the chassis just under the rear seat, or some where solid that you can weld a good earth mount to the chassis.
The best earth mount is only to the chassis, and to do this properly you will probably have to have a earth mount welded onto the chassis somewhere reasonably close to the battery.
Running an earth cable all the way to the front is only a waste of money and will only lead to a greater resistance for current flow from the battery to the starter.
A good chassis mounted earth point is far better then any long run cable.

I'm sorry to say this but some of you need to go back to school and learn some of the basics of 12V systems before you start playing about with any of your cars electrical system.
With a 12V system, you need to run as big a battery cable as you can fit in your car, if you are running it from the boot. This is especially true if you are also running high powered stereo setups.
If our cars were 24v then we could get away with a battery cable of about half the size due to having twice the voltage, doesn't need to produce as much current to do the same thing.

As an example in my own car which has a large Odyssey battery and 00 gauge battery cable run to the engine bay into a handmade distribution block and then about 2gauge cable from the distribution block to the starter motor.
Also 4gauge run from the distribution block to the cars fuse compartment.
Also from the battery I have a short run of again 00 gauge earth cable down to a custom earth mount under the rear seat ( not directly under obviously ) to the chassis.
I have never had a problem starting my car and it runs a high powered stereo as well.
My car will still start first time, even with my battery down to 10volts.
This is due to a good battery and the starter motor being able to draw high current through a very high quality battery cable.

The only down side to the sort of set up my car has is the extra weight. It may not be much, but it is a bit.
This is easily overcome as my car is turboed.

I hope some of what I have written is helpful.

Rotaman

sweet deal, thanks for the confirmation Team!

I choose the 925 :)
http://i1139.photobucket.com/albums/...227_134649.jpg

fwiw, using cableyard welding wire, 2awg, and getting virtually 0 voltage drop between battery and distribution block under hood. Measured with multimeter.

Thats good to hear.
How much voltage drop are you getting when the cars starting?
Most problems I've seen over the years, are normally caused by bad workmanship, ie, the connections are not done properly.
I believe that all battery connections should be crimped and or soldered.

Here's a question? Do you think your battery system could turn you starter motor over for 5-10mins non stop? This will put a lot of load on the starter. Best make sure you have a good one before putting it to the test.
If you can say yes , then you system is probably fine.
If you say no, then maybe you should sort it out so it can.
Try it one day, see what happens, if you have someone with you, get them to touch every join in the system from the battery to the starter motor and see if any of the connections are warm or hot to touch.
If any of them are getting hot, there will be one of your problems, that will be a bad connection.

Have fun.

Rotaman

Not sure how I got the know it all label, lol

Go back and re-read my post. It was not a shock mount attachment point. It was a chassis stud for the upper shock mount support brace. Regardless, I have never had a shock mount bolt loosen. Probably because I tighten them to the proper spec upon installation.

answer to 9krpms results for the reply below this one:

https://www.rx8club.com/series-i-do-...8/#post4465119

I am seeing voltage drop while starting at the front where the positive 2 gauge (high quality) is connected to the factory Positive wiring. All of my terminals are soldered except one that will be soldered and have a new Taylor connector on it. And my main ground in the rear goes straight to the chassis in the trunk.

Sorry for the crappy night time cell pic

http://www.flickr.com/photos/9krpmrx8/8510664307/
I somehow think the issues is the non soldered connector that connects to the factory positive wiring. But of course I know little about electronics. But we will find out this weekend when I fix that connector and solder it.

9K, I've had a look at your photo, and the point you have used for your battery earth is not a good location.
I know that Mazda mount a couple of small earth points there, but those little earth points don't have very much current running through them, so they don't really matter to much. Don't forget we are talking 100amps plus when you are winding over the starter motor, and if you have a few bad connections in the starting circuit, that current draw could end up being double.
Think of this as an arc welder and thats the sort of current we are talking about.
Your battery earth needs to be mounted on solid Chassis rail, not a point which is only held in posistion by a couple of small spot welds.
That whole section that you have mounted your battery earth too is only spot welded to the chassis. You need to have a direct connection to the main chassis rails.
Be aware that a lot of screw type battery connections, like that used in a lot of car audio setups, might look pretty, but are not that good at actually making good connection with the battery cable. A lot of them use a grub type of screw, which is good for ripping the cable strands to bits. Crimp connections are a lot better and more permanent. Better still crimp and soldered.

9K, Here is something else to try, crab hold of that earth cable in that photo and pull it upwards, with a reasonable amount of force. If you can move the terminal under the bolt with that bolt done up tight, then you know that you need to mount that terminal onto a mount which has a lot bigger bolt.
Hope this is helpful.

Rotaman

+1 Like

u know, a technician laughed at me that moving the battery to the boot would not affect cranking time since electricity moves at the speed of light...

But then again...


electricity is still constrained to resistance of wires, quality and condition of the cables used...

go for it and let me know...

What Odyssey are u running on?
pc925 or pc1200?

im on pc925 with 0ga wires.. (thick) have not put any earthing yet..

any pics to share of ur setup?

I'm using the larger PC1230 which is one of the more moden pastic case batteries models.
I will have to take some photos and post them up.
My distribution block sits behind the water washer bottle and is up against the firewall.
I ended up making my own distribution block, as I couldn't find one that I liked that would fit in the confined space I had available.

Rotaman

So here is the car starting up after my drive home from work (fully warmed up, about 20 minute drive)

At battery

At Alternator

Battery voltage doesn't drop much on cranking which is expected. Alternator drops to about ~9.5v at the lowest but the starters in these cars are pretty beefy and this is probably common for people that don't have relocations.

I didn't even consider doing that test, guess I will do that this evening :)

Test the voltage from the positive battery terminal to the positive on the starter during cranking. Do the same with the negative battery terminal to the engine ground during cranking. That will tell you if your voltage drop is across the positive or negative half of the circuit. But it sounds to me like your car is starting just fine. You should hear mine with the 6 awg.

paimon, if its winter time where you are and your car starts as easily as it seems to in the video's you posted, then I would say your setup is fine.

Rotaman

This is one test i wish i could do, but there really is no way to pull this off unless i get reduclously long DVM leads lol.

Yea its winter time here, never had a problem starting all winter. Sometimes i get a slightly slower crank when the car has been sitting outside (at work), but doesn't take even 2 seconds to start.

? Just use whatever leftover cable you have laying around...

ah i get what you're saying now, sorry i was thinking of something else. Question, just so i dont have to keep turning the car on and off (lol) can i just yoink the ignition fuse and crank that way.

Hold the gas pedal all the way down while you try to start it. It disables the fuel injection and you can crank to your heart's content.

bah, noobed. I'll give it a shot tomorrow when the gf is awake so i can get good readings.

k just tried it with her.

roughly 0.10mV (most likely noise) between two ground points during crank
roughly 283mV between positive lead and alternator

didn't get starter yet, probably will this weekend when i have some time

btw, ground to alternator w/ a 3 second crank, didn't drop below 9.8?V

Sounds good to me. I'd say you have nothing to worry about.

Here are a few photos of my battery setup as it is today. My car is a JDM model, so remember this is right hand drive.

First photo of the boot with every thing in place

Attachment 227450

Second photo with carpet removed for access to battery etc.

Attachment 227451

Third photo is close up of custom made battery box and quick cut off.

Attachment 227452

fourth photo is underneath back seat - earth mounting point, this is welded to the chassis. The positive cable is the one next to it covered with the protective plastic covering.

Attachment 227453

fifth photo is close up of earth mounting point. Welding in that area was differcult, so not the prettiest welding.

Attachment 227454

Six photo is in engine bay where you can see where the positive cable comes through the grommet in the firewall and tucks up behind the washer bottle.

Attachment 227455

Seventh photo is of custom made distribution block which has single 00gauge input and 1x 2 gauge ( to starter motor ) and 1x 4 gauge output ( to fuse box ).

Attachment 227456

Hope this is helpful for someone.

Rotaman

How did you screw in the battery tray. I had a lot of difficulty in putting a bolt through in that location due to the lack of access from under the car. I ended up mounting my battery next to the tail light which is not ideal for weight distribution.

How I mounted the battery box and sub tube was reasonable easy.
I pulled the carpet out and mounted a piece of 12mm ply wood down to the floor in that top area behind the seats.
I have 4 x 6mm bolts that come up through the ply and the carpet and this allows me to drop the battery box down over the bolts.
The only unfortunate part is because of the lack of room under that area, I have to fit the battery into the battery box and lift it all into posistion in one go.
Lifting 20kgs of weight with your arms stretched out and leaning into the boot is not easy.

Rotaman

how is the plywood secured to the floor.

I did not want to simply use self tapping screws as the weight of the battery will probably rip the battery tray off in an accident.:Eyecrazy:

Nice !!!


im using Odyssey PC925 and like skc, have it bolted down just right behind the left taillight. I have yet to earth it to any chasis ;( but i did purchase the Okada Project plasma lift to "stabilize" currents but have yet to fix it.. any comments on this?

I do have the updated starter and my alternator wa changed 1 and half years ago. A talked with Lotus Distributors the other time, they did mention and felt that the Rx-8 alternator was abit small for the car.

im not sure how true is this but their current Lotus are equipped with Odyssey Batteries and have no issues with starting and they stated that it might be the small alternator.


I see you have a distribution block. i thought those are needed if you an amp.. do u ?

The piece of ply I have in the back there runs the full width of the car and is screwed down to the floor at multiple points, it will never rip off the floor.
I use that same piece of ply to hold down my subtube as well.

Yes I do have a large 4 channel amp in the car, but the distribution block is not used for that. The amp gets its power direct from the battery.

Must admit I don't know anything about the Okada Project plasma lift, but it looks like a type of CDI unit.
If you are looking into CDI units, try M&W in Australia, they make CDI's especially for Rotaries. Very good products.

Rotaman

What did you end up doing with the EPS fuse?

I wired the EPS fuse into the fuse box, so it looks like its part of the factory fuse system.

Rotaman

very interesting. I need to find a nice clean way to do my hot wire. right now I am doing mine this way:

http://www.normalexception.net/menal...g?m=1360617257

crappy i know.