I am thinking of starting my electrics. Those with Rover V8's or large engines, what battery have you got and what do you think of it?

Thanks in advance!

i had big one in my 3.5 v8 landy but it died so I fitted the one from my kit car, much smaller and it starts every time.

will post more data when I get home and remember ....

The MGB V8 boys us a type 063 because it fits where one of the two 6 volt batteries was.

Google battery 063, for supplier / prices.

I have a std 50 or 60Ah car battery, and is starts my RV8 Viento with no problem. I have 9.75:1 compression ratio as well. (some P6 engines had 10:1 cr)
Had this battery nearly 4 years and no problem.
You really dont need a stonking great battery for a Rover V8. Its not a Land Rover Diesel in which case a 110Ah battery is a necessity.
Most of the V8 Vientos (and 90% are RV8's) I know of only use Std car batteries. I don't recall seeing anyone with an unduly large battery at any of the shows.

I think you are worrying unduly for a kit car.

Ideally I would advise a 096 --- typically something like 720 to 780 peak cranking amps 72 to 78 amp hours capacity --- varies between manufacturers --- typical uses in 2 litre diesels such as the Rover 75 diesel or KV6 petrol.

You will get away with a 075 battery typically used in 1.8 and 2 litre cars 600amps peak cranking 60 AH

The next size down is the 063 which is usually 400 amps, 38 to 44 amp hours --- perhaps a wee bit too small.

[Edited on 15/1/10 by britishtrident]

[Edited on 15/1/10 by britishtrident]

And look at the length of warranty when buying a battery, it is a good indicator of how long the battery will last, look for at least 4 years, 5 or even 6 years for latest improved chemistry batteries.

Worth paying 75 quid or so for a good quality type 096 with a 5 year warranty -- shop around you can find Bosch

I'm using a bog standard 40Ah, 360 cranking amps battery and it works just fine.

I wouldn't waste money on a large (heavy) or fancy battery because the nature of a kit car means that you will probably need to charge it up from a mains charger every so often anyway like after the recent weather...

Once charged you don't tend to sit around stationary with electrical loads (eg radio) switched on draining it.

Just make sure you have good beefy earth straps between engine and chassis and battery with good clean connections. That is worth more than a fancy battery IMHO.

Cheers,
Craig.

A small battery may start the engine just fine but the battery life will be short, the reason is every cold start will result in a near deep discharge of the battery.

Apart from reducing the charge capacity every deep discharge and recharging cycle the "self-discharge rate" increases ie battery gets to a stage where it "won't hold charge" --- the charge leaks away.

In simple terms it is not a good idea to repeatedly drain a battery below 80% of its full charge capacity.

If you drain the battery right down to the last 20% of its capacity most modern car batteries will simply give up the ghost.

Using no load voltage as a guide to battery charge

At room temperature.

Old Fashioned Lead Acid Battery
Voltage no load Charge State
12.7V 100.00%
12.5V 75.00%
12.2V 50.00%
12.0V 25.00%
11.9V or less Discharged


Calcium doped Lead Acid Battery
13.3 100.00%
13.1 75.00%
12.9 50.00%
12.7 25.00%
12.5 or less Discharged

Has been discharged it should charged immediately.

[Edited on 15/1/10 by britishtrident]

I don't doubt the theory behind what you are saying BT but I've had the same battery in my car since I started building it and it seems to cope just fine. It is now 5+ years old and showing no signs of distress.

It holds it's charge for weeks on end and will still start the car even though most of my journeys were only 15 minutes or so due to engine cooling issues. Sometimes the V8 needs a good 6 second (or so) crank if it has been idle for a while and the carbs are dry but it does this without any sign of labouring.

I just can't see what I'm missing by having a regular battery. Isn't Locost all about keeping costs down and back to basics motoring? If you spend £75 on the battery you've only got £175 left for the rest of the car...