Sorry seems like a noob question so don't flame me too hard. Taking my car back from a track car to use as a daily driver. Problem is I've been running a PC680 and I just don't think it has enough CCA to start the car over multiple times in between short drives. As I have all the mods, my V mount has really limited the space to put a regular size battery in the stock location. I was looking at lithium batteries Shorei and the like because they are small but the manufacturer does not suggest them for auto applications. I really don't want to relocate battery (seems like such a pain...and I can't seem to pull up Moconnors write up anyway without being redirected to a Stanford University web site). Questions are:
1) what's my minimum battery output need to be?
2) is there such a thing in a small size?
3) does anyone have the link to Moconnnors battery relocation write up.

 

My full size battery is in the hatch

https://www.rx7club.com/3rd-generati.../#post11811672

 

Been using


for 2 months now as a DD and have no problems. Great small battery so far

 

I've fit an Odyssey PC920 by mounting it sideways in the stock location with a custom bracket. XS Power also makes some batteries that may fit. I still recommend a trickle charger on any of the AGM batteries if the car sits for more than a few days.

 

This link should work, it was posted on the last page of his write up.
http://www.ls1fc.com/pdfs/FD_Battery_Relocation.pdf

I followed his write up and using the Miata battery, only issue I have is I can't leave the battery connected or else it'll be drain within a day, but that happen with the stock battery too so I don't think it's a battery issue, just have a small drain somewhere I need to track down. With the 150A breaker I just disconnect it every time I park the car, and it has been working great for 2 years. I don't even need to trickle charge it often, only put it on a trickle charger every other month to ensure the battery is good, and I run the IRP 140A alternator to keep up with the charge during drives and I don't have any issue with short drives

 

I usually run 2 grounds to any relocated battery. Sand the ground location down to bare metal. Apply dielectric grease to prevent rust.

 

Meant to say "for 2 months NOT as a DD..." I've left car sitting in the garage, battery still connected (by mistake), for almost 2 wks and started right up.

 

I got sick of jumping my car. Bought a full size AGM battery and problem solved.

 

good stuff. thanks for the tutelage. However, wouldn't this be easier to just wire the cables in parallel with a fuse on he power cable and a cutoff? The Fuse block thing seems unnecessary? I get it from the stand point of adding other electrical components but isn't this just over engineered? Opinions welcome please. Also still no advice on min CCA. Car is rated for min 550 CCA. Can I do less and still get reliable starting performance? Sorry just don't know that much about this stuff.

 

Just to give you a data point, I have an Optima yellow top, IIRC, CA 550, CCA 450. If I leave the car for a couple of weeks the starter will turn more slowly but it has always started. Have never gone longer than that between starts.

Had to cut out the bin "bucket" to get it to fit. Top to bottom it just fits with my custom made battery tray.

 

The fuse block makes it easy to add accessory to a switched source, adding new fuse and find a new source every time I need to add something electrical related is a hassle. Miata battery is rated at 400CAand 320CCA and it works fine for me, another thing you need to look at is the reserve capacity, a battery with high CCA but low RC is not gonna work very well.

 

been using that pc680 battery a couple of years now, never a hint of low power even on short trips. love the small size and power output