Biggest battery for MK2?

[Odin_S]

It seems looking at my volt meter i rarely get 14 volts now I've installed a bigger kenwood unit.

What's the best battery i can get to give the biggest charge? Same with the alternator

The best I'm getting at the moment is 13.4 volts on a long drive

[craig]

Have you drop tested the battery to check its condition?

[C35Rob]

It seems looking at my volt meter i rarely get 14 volts now I've installed a bigger kenwood unit.

What's the best battery i can get to give the biggest charge? Same with the alternator

The best I'm getting at the moment is 13.4 volts on a long drive

Standard capacity battery and an alternator in good condition is fine, if you're not getting ~14.4v across the battery terminals with the engine running the alternator is most likely to be at fault.

[Odin_S]

Hmm, the battery has discharged a few times, with the car have an engine rebuild last year and me working. However, the battery is less than 18months old...

[craig]

A while ago I had a new battery that was faulty. Returned it and swapped it for another one.

[juliankv73]

A while ago I had a new battery that was faulty. Returned it and swapped it for another one.

Bought mine from Halfrauds, calcium one, kept discharging, they tested it and said it was fine, took it back the next day (different person), who checked it and said its likely the battery and swapped it no trouble!
and swapped under warranty if poss

[C35Rob]

once a battery has been deep discharged it can often hinder it's ability to hold charge in the future, but you should still be getting a decent output from the alternator.

[Martin F]

You sure the battery isn't draining when parked up, my Audi had a fault and a fully charged battery would be Flat within 72 hours.
The mr2 on the other hand will start without problems after a 5 week rest

P.S. I have had many cars running high powered amps and rarely come across problems, when i do they are either a dud battery, faulty alternator or excessive power usage while parked up, bad earth somewhere maybe ???

[Odin_S]

If my kenwood (one with a screen satnav etc) is not on, i get 14v and 13.9 is the lowest it will go. Once on it goes to 13.5v

I think i need a battery this one as discharged a few time. From not being used for weeks. Plus last week it wasn't used much because the engine was being rebuilt

I left the car parked for a week last week and it started fine.

I'm going to have to put a trickle charge on the car to help when not in use.

Just want to know what the biggest battery i can get for the car

[Martin F]

If my kenwood (one with a screen satnav etc) is not on, i get 14v and 13.9 is the lowest it will go. Once on it goes to 13.5v

I think i need a battery this one as discharged a few time. From not being used for weeks. Plus last week it wasn't used much because the engine was being rebuilt

I left the car parked for a week last week and it started fine.

I'm going to have to put a trickle charge on the car to help when not in use.

Just want to know what the biggest battery i can get for the car

biggest as in size / capacity ?

If that is what you are looking for then measure the hole in the frunk and take it from there, personally i think a new standard battery will do you fine. If i had to upgrade, i would be focusing on a higher output alternator, but from what you have posted, neither upgrade is required ....

[Odin_S]

Hmm where could i get a higher output alternator?

[craig]

Hmm where could i get a higher output alternator?

You do not need a bigger battery or uprated alternator to run a headunit.

Have you done this?

Have you drop tested the battery to check its condition?

Following that, as above, look at problems with the alternator.

[Odin_S]

Hmm where could i get a higher output alternator?

You do not need a bigger battery or uprated alternator to run a headunit.

Have you done this?

Have you drop tested the battery to check its condition?

Following that, as above, look at problems with the alternator.

Thanks for info, I'll research how to do a drop test now.

[Al-sw20]

This thread reminds me of people wanting a brake upgrade because their original brakes are old and worn out.

[Odin_S]

I'm only saying this because before i got a new ice system, walbro Fuel pump. Basically before the rebuild it didn't go down this low.

I'm thinking the fuel (sounds like it is anyway)
And ICE are taking more juice than before

That and the battery has been left standing for a combined total of 5 months to discharge.

[madbasshunter]

The biggest battery I could get to fit is an 096

Before upgrading the alternator upgrade the charging wires (known as The Big 3)

Where you add additional bigger cable (I use 0 gauge) from
The alternator to battery (I used the starter cable)
The battery negative to body
The engine to body

This makes a big difference to the charging system mine only drops to 14.4 when booming