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Fitting a bike battery to a car?

23 April 2011
Melbourne, Australia
Just curious if anyone has done this before or knows if it would be ok to do.
The battery in my 91 nsx has recently died and I am in need of a replacement, prefferably something much lighter weight than the current battery, but its not a daily driver so it would need to last a week between drives. There is a company called Shorai http://www.shoraipower.com.au/
that make lithium batteies which are at least half the weight of standard lithium batteries that also last longer, I know i would have to change the terminals on my car, but other than that would it be ok, provided the battery had the same voltage and cca rating.

Or is this just a terrible idea all round?

I have installed a light weight sealed battery into my civic and crx similar to the odyssey pc680 without the odyssey price. Found the battery on eBay under UB12220 for about $38, they can be installed in any position. I ordered some adapter terminals for the battery as well and I did not have to mess with the vehicle wiring. The posts were called flag to top post conversion connectors $7 each, bought them from solarseller.com in North Long beach. You can always match up your existing battery specs to a universal battery. Hope this helps.


I would just get a Battery Tender Jr. (in AU you can get an OptiMate if you can't find the Batter Tender) and use that to keep the battery charged while you're not driving it. I have my Batter Tender Jr. wired into my battery, and I just disconnect it when I want to go for a drive (I put a sock on my shifter to remind me to disconnect the battery tender so that I don't drive off and damage anything).
There's a good battery thread floating around somewhere. It may have been TurbotoGO who started it if I remember. He was comparing lightweight batteries so maybe start looking for that thread. Also discussed in that thread were companies that made the battery and other companies that just bought and rebranded them for a markup.

There's also some threads on motorcycle batteries as well but I forget exactly what the "conclusion" was from them if they're good to run or not. If I remember they didn't give enough current to crank the engine like Honda wanted...
I just bought the Shorei battery it has been in the car for a week so I cannot tell you how good it is for a long term review.
I have gone through so many batteries over the years I just thought it was part of owning this car in 14yrs probably 8 batteries.
I tried to order some stuff off Dali one of the items was the PC680 bracket/holder when none of it arrived and I got my money back I started looking for alternatives I spoke to my auto electrician and he told me the PC680 was a 'crap' battery don't touch it. His words not mine before anyone takes offense.
Let me say first impression is, when I picked up the box i thought where is the battery it only weighs 2.2 kgs normal batteries are around 18kgs.
It also comes with a battery tender which is an additional cost but I was going to get one anyway as regardless of what battery you buy you will need one with these cars if they are no longer daily drivers mine was but not anymore.
The cool thing about the tender is the battery has its own unique slot sort of like a USB slot on your laptop so the tender connects there if its not in use it has a rubber cover that sort of clicks in to keep out moisture etc.
To make sure the battery stayed where I wanted it I made a cardboard template and took it to a steel fabricator mate of mine and got him to make me my battery box and powder coat it if you like I will post some photos over the next few days when I get around to it.
First impressions starts like a charm first time every time so far, I have now left it for 4 days unattended without the tender on and plan to start it up tomorrow the reason for this is if I go away for the weekend that is about the length of time it will potentially sit unattended.
As for the battery cables on the car I was going to change the connectors out but just did a rough job using the originals until that happens as there are a few mods going on the old girl shortly so that was going to be sorted then.
In my spare time my other passion is dirt bike racing, Red Bull KTM just announced that they are using this battery exclusively from now on so these must be able to handle the odd bump, I thought I should add that as there has been comments about shortening the lifespan of batteries from too stiffer suspension and hard out driving on tracks and bad roads.
one last thing in the 4 days of driving with this new battery I have had the A/C on and my stereo up loud, I normally prefer the engine noise but thought this was important to test.
Anyway will let anyone know how this new battery goes if they're interested.
Shorai Battery Group Buy Thread

I too have the Shorai setup and so far so good - highly recommended. Check out the thread for my install notes: