Battery drain, and battery Brain.

[donr]

I have a V220 cdi which I purchased second-hand. The guy I bought it off had a second battery installed, under the drivers seat.The reason for this was because he had a lot of extra gadgets fitted which consumed power. I found that if I left the vehicle sitting for much more than a day, it would not start, and the battery would be flat. He was aware of this problem, and had a dedicated charging point installed so that a charger could very easily be plugged in at any time. There was also a gadget fitted to the positive terminal of the main battery, which could disconnect the battery by means of a remote control, to conserve the power of the battery. Sad to say this gadget was destroyed by an 'assistance service' in France who reversed the polarity when trying to start the engine.
I was recently in America, and searched the internet for a 'battery switch' and eventually found a site named 'Summit Racing', who had the exact replica of the gadget I had on my battery. It is known as the 'Battery brain' and monitors the state of the battery continuously and desconnects at a certain level to preserve the charge in the battery. It can later be reconnected either via the remote control or manually with a button. The interesting thing I found, was, (according to a post on the internet,) If two batteries are connected in parallel, one battery will always starve the other, but only when the engine is not running. This seems to be exactly the case with my vehicle. The solution of course is to disconnect the battery when the engine is not running, and then connect again using the remote control to start the engine.
I thought this may be of interest to members, and I can email a copy of the instructions for the battery brain if anybody wants this.
It cost me $100 dollars, and I am happy with that price.

 

[corned]

The interesting thing I found, was, (according to a post on the internet,) If two batteries are connected in parallel, one battery will always starve the other, but only when the engine is not running.

You could always try connecting them in series to prevent this.









(No, don't - I was only kidding!)

 

[donr]

Glad to hear that !

 

[Stan the Man]

You could always try connecting them in series to prevent this.









(No, don't - I was only kidding!)

If you connect two batteries in series you will supply 24 volts. Not good for a 12 volt system !

 

[corned]

Which is why I thought I'd better add that I was kidding!

Although it would solve the problem of one battery draining in preference to the other...

 

[davidjpowell]

You need the sort of gadget that boats use. They have the ability to charge both sets when running, but one battery is kept for the engine.

Not sure how this is done though. Some sort of relay I would think?

 

[donr]

I should just add that I have now fitted the device (which I guess is a relay of some sort) and it works fine. Just press the remote and the battery is disconnected, then reconnect again when I need to use the vehicle. My batteries both charge when the engine is running, it is only when the vehicle is stationery that one battery can starve the other, so disconnecting the main battery solves the problem. Thanks for all comments.

 

[bolide]

A split charge relay stops the batteries discharging each other

The best way to solve this would be to find out what's causing the current drain. Electrical items shouldn't draw current if they're off..

Nick Froome