Low volt disco for radio and aux ports

[Wrangel]

Hey
Any ideas and input wanted on a low voltage turn off on stereo and 12 volt ports front and rear. Amps would be total for the radio + fuse total for the 12v ports and of course the point is so I can still start the jeep.

[Wallyd]

2nd battery with isolator

[hunty]

Maaaaaaaate

I am not exactly sure what your question is asking but My JK has this feature built in.

It is impossible to leave anything (factory) on, the JK computer control system will turn off the head lights , radio / stereo , interior light at around 11.5V this preserves just enough power to start the engine.

If your question relates to Non Factory equipment connected directly to the battery then there are a host of options;

I run a little black box between my Engel fridge and my second battery to ensure that I never run my AGM battery so flat that I damage it (11.5v).
I also connect my other accessories such as LED camping lights, camera battery charger, portable lcd TV and computer adapter etc via the low voltage cut out black box - this not only protects the AGM deep cycle battery it protects the equipment connected to it!

Basic electrical theory dictates that voltage and current are linked. As the battery voltage slowly drops as it is consumed by the connected accessories the amount of power (measured in amps) required to power the accessories slowly increases;

100watt load powered by a full battery 13.8v = 100/13.8= 7.25Amps
compared to the current draw on a near flat battery;
100watt load near flat Batt 11.5v = 100/11.5= 8.7amps
which is approx 20% more current required as the battery goes flat, this can stress/damage electrical equipment and it is advised to NOT run any electrical equipment designed to run on 12v on less than 11.5 - equipment failure would be predicted below this (10.0v etc)

1. Low voltage cutout blackbox
2. high voltage / low voltage protector black box
3. hi tech dual battery controllers will sometimes disconnect the Aux battery at a preset low voltage protecting the battery and equipment
4. solar charger / controllers - some of the better ones will also act as protectors.

I run a Wired HDH switch to control all my accessories and it can be programmed to cut out at 11.5v and this is how mine is set - I would have to use all my dumbassery skills to end up needing a jump start LoL
cheers Hunty





http://www.12volt.com.au/

[Wrangel]

I suppose I'll throw on the fridge in the back overnight and see if I can start it in the morning, I didn't know from factory that this feature was built in. I already am looking at low voltage disco for direct connect stuff but now I know it has a built in one I'll just run a 12volt relay from the rear port, when it gets cut it will trip the relay..

[Wrangel]

Hunty - can I flatten the battery from the 12v port in the back?

[oldmacdonald]

Originally Posted by hunty

As the battery voltage slowly drops as it is consumed by the connected accessories the amount of power (measured in amps) required to power the accessories slowly increases.

Not correct. Power does not change and is measured in Watts. Current is measured in Amperes. Power is the product of voltage and current:

P = V.I

Current (amps) increases as voltage decreases, as voltage multiplied by current remains constant.

[Wrangel]

Anyway, so is it possible to flatten the battery from the 12volt port in the back or will it shut off?