I've seen people having an extra car battery in the boot for the extra ICE they have.
I am thinking of installing a small extra battery in the arm rest to boost the power of my existing racing battery.
Question is, what is the proper way or doubling a battery and is there a problem with mixing different battery types and size? For instance, can I add a small 12v motorcycle battery with the 12V car battery?

I am running two Acid lead batteries. I've heard it's bad to mix Acid and AMG.

Why an extra battery instead of a high powered alternator? If you're using more power while driving than your alternator puts out an extra battery is going to do absolutely nothing for you.

The extra battery just gives you extra reserve power if you're using a lot of power while not driving the car.

Running a cal and battery do help, but they strain the alternator as well, having to keep both of them charged constantly.
It's a better idea to have a high output alternator for ICE.

Let me chime in about this topic:

It's not the best idea to run batteries in parallel. ( maintain 12 volts but doubles the amp)

The reason is if there is a difference between internal resistance between the batteries one acts like a resistor and drains the lower resistance battery.

This is the same reason why golf carts use big 6 volt batteries in series. You get double the amps and maintain the same volts with out internal resistance issue.

The proper way to install a parallel battery would to install a glow plug solenoid between the booster battery that only is connected to your vehicle battery when the ignition is on. The theory is the booster is only connected when starting and charging. And completely disconnected while the car is off. This is to avoid internal resistance draining mention earlier.

But once you factor in all that crazy extra wiring and extra battery. Your better off buying a li ion battery in the first place.

http://www.jegs.com/p/Lithium-Pros/Lithium...770167/10002/-1


I hope that helps. Yellowchinaman, what symptoms are you having to want an extra battery?

This post has been edited by Hanyo: Mar 19, 2014 - 1:18 AM

Thanks guys.
You see have a small battery mod which Im dependant on using a Caterham Banner battery. (The smallest 12V with enough amp for the GT4)
Only problem is that it never holds very well and when the car is not in use it lives off a trickle charger.
As a track car it's ok. But as a normal road car it's not ideal.
After say 5 days the battery doesn't produce enough to start up.
Its not a simple case of changing for a better battery because there is no other battery smaller or that size that produces enough power and for me to keep it in that location.
I know the logical thing to do is to relocate it to the boot and I can have what ever battery I want.
But I use my boot space a lot and don't want to compromise it any more hence why I was thinking of doubling up the battery in the arm rest.

you dont have anything draining the battery do you?

I have the same issues with my Braille battery. It either lives on a Battery Tender, or I have it disconnected.

Get a quick disconnect terminal for the negative lead and leave it disconnected when not in use. Works for me!

Look into XS power. AMG technology, used by many competitors in SPL events and racing events. I believe they do have an importer for UK.

>

None small enough the same size as the Banner which produces the same power.

The only drain I have is the alarm which isn't much.

Relocation of the battery to the passenger foot well?

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Isn't having battery inside the cabin dangerous? I remember reading somewhere about some fumes. Also - if the car crashes, the battery can squirt acid all over your passenger.

If it is a safety hazard, I'd even avoid the trunk. Maybe try and squeeze it somewhere in the engine bay.

There are two things to prevent this.
Buy a sealed battery. Build a box to enclose the battery. Doing both is suggested.

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Not true. Golf carts are put in series to up the voltage. You put 3 12volt batteries and series and you have 36 volts with the same amount of amp hours as a single battery.

BMW's, Mercs and Audis have batteries in the boot. Some like the Q7 have it under the seat. As long as its secured its not an issue.
It looks like I am going to HAVE to move it to the boot. However I am considering putting it behind the plastic where the antenna motor is and build a small battery tray there as to the opposite side to where the jack is kept.
Now I just need to find a VERY powerful battery yet SLIM/FLAT enough to fit there.

Any suggestions?

This post has been edited by yellowchinaman: Mar 19, 2014 - 12:37 PM

Again, XS Power

Ok. So im struggling to find a battery which cranks out
60Ah
500A+ cca
And thinner then 80mm
being sold in the uk.

So another thought. Can I buy 2 motorcycle battories which are smaller and easier to hide int he boot instead?
Or even make my own battery by wiring a series of cells? If so what cells and where?

This post has been edited by yellowchinaman: Mar 20, 2014 - 3:47 AM

>
Ultracapacitor cells.
There is a video of a guy who used 6 D-cell sized capacitors in place of a battery. He has several videos chronicling his progress.
https://www.youtube.com/watch?v=8miq6sDy0wA...be_gdata_player

It wont store very much energy but it has far more cranking amperage than any type of battery. Capacitors are able to fully charge or discharge in fractions of a second because they actually store electrons instead of converting electricity into chemical storage. You may only get a matter of seconds worth of cranking though depending on how many Farads the caps are.

This post has been edited by Special_Edy: Mar 20, 2014 - 4:03 PM

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DUDE! Thats perfect! Funny enough my friend told me to do the same thing but needed a power management system like what this guy was saying in the end.
Thanks

>
Woops you caught me off guard. You are correct, running in series will increase the volts. But the point I was trying to make is you get a safe and smart way to take advantage the batteries amps while maintaining a 12 volt system.


Have you consider this? Easily hide in the quarter panel. They are sealed to prevent gassing.

http://shop.advanceautoparts.com/p/optima-...wAJg#fragment-2


It's better to run two 6 volt batteries in series then to run two 12 volt batteries in parallel. Like I mention before, internal resistance issue, charge and discharge rate issue and shorten life span.

Looks good Hanyo
I could probably use this to make a Hybrid Cell.
Optimata Red Top 6V merged with 6 D-cell sized capacitors.