Battery monitor

Easiest way I've found is to have a simple digital voltmeter hooked up to the second battery. It tells you the voltage to one decimal point, so you get an idea of how full or empty your battery is, and it will tell you that your second battery is getting recharged too.

As a rough, rough guide, your battery will be fully charged at about 12.8 volts (at rest). Might be half gone at 12.3 volts; Almost fully empty at say 11.9 volts.

When you are driving along, you'll know its being recharged at about 14 volts.

I use a combined volt/ temp gauge available from Jaycar electronics for about $35. I put a switch in line, so I can turn the meter off.

Cheers
phil

Michael,

Will be a little difficult to monitor the battery in the Camper, unless you do some re-wiring.

As far as the dual batteries in the vehicle are concerned, I have a simple solution.
(This requires a socket, preferably in the front of the vehicle, that is connected to the auxiliary battery, plus the original ciggy socket, connected to the primary)

Purchase a volt meter from Jaycar which has a ciggy plug on it and a velco backing.

To measure the voltage from either battery, simply plug into the corresponding socket. This will tell you when/if the alternator is charging, (should show about 14.1 - 14.2 volts) and the residual voltage level of each battery. (but accurately, only after vehicle has been at rest for several hours)

There are of course other solutions, but not as simple, or cheap.

Perhaps a cheap multi meter (or the volt meter mentioned above, removed from the vehicle) is the easiest solution to measure the Camper battery from time to time.

Hi maxmcclo,
Have a look here ,i have one of these battery monitors and it works great certainly tells you more than just battery voltage.
www.outbackaccessories.com

I made my own from a Dick Smith kit. I did make some mods to reduce the scale and improve the resolution and added a switch so I can switch between aux and main - all up mine cost me an hour and about $20 worth of bits. I find it really usefull and would recommend you do install something.

Mine's basically the same in function and operation to the Pirhana or Engel ones. (They are unfortunately over priced for what's in them and the fact that the design is common but that's life.)

Some like the Engel have the added advantage (one of the Pirhana does too) of being able to drive a relay to switch off devices at a preset "flat" voltage which is a good idea, especially if you are using gel cells which are permanently damaged if taken too low.

Dave

The one I use is a multi purpose unit "time, date, inside and ouside temperature and volt meter" about $40 from Leading Edge Electronics. Velcro it on to the dash and run the cig plug to what ever battery you are monitoring. Has low voltage alarm and ice alarm which has been going off a bit here in the mornings (Nanango) 2 hours north west of Brisbane -2 today.
Cheers Bruce.

I use a dual battery twin LED bargraph monitor purchased from Opposite Lock. I have wired it to both sides of the isolator but you could just tap off any of your two runs. I like this unit a lot as it has some neat functions - ability to turn off the displays independently; both displays have independent low voltage warning beepers, etc. It is easy to mount anywhere, light, and "resonably" priced, too.

Works for me, perhaps not for you.

Regrads.

I looked yesterday at a new one that TJM are developing for twin batteries.

Looks REALLY good, although this proto is a little big.

Give Alan at Outback Accessories in Seaford a call.