# Battery condition indicator



## namder (Sep 20, 2006)

I want to have a visual indicator of the leisure battery condition inside the motorhome other than the very vague series of lights fitted to my Autotrail Apache 725. Any recommendations, I have 2x110 Ah batteries fitted in an external locker.

John


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## cabby (May 14, 2005)

you could have a Volt and an amp gauge fitted if you really think you need it.

cabby


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## listerdiesel (Aug 3, 2012)

A voltmeter won't tell you a lot, unless you know what the battery is doing at the time, charging or discharging or just sitting there..

An ammeter will tell you what charge is going into the battery, but without interpretation it will not tell you much about the battery.

So:

If you fit a voltmeter, you can tell with a bit of experience what the battery is doing and what its state of charge is, and also if the charging system is working.

If you fit an ammeter, particularly a centre-zero type, it will show both charge and discharge and whether or not the charging system is keeping up with the discharge rate.

Personally, I'd fit a decent digital LED voltmeter with a 'push to read' button so that it isn't on all the time. You can make spot checks any time and gradually work out a 'normal' range of operating voltages.

The ammeter is more diagnostic than useful, but again, it could be a push to read display and if it had negative reading capability as well as positive reading, that would show what was going in and out of the battery.

The voltmeter would need to have a fuse in its circuit, and the ammeter would normally have a shunt in circuit where the current is to be measured, with lighter wires to the display.

Many such devices are on ebay, but those that need a separate meter supply to run the electronics, usually a 9V PP3 or similar, are more complex to fit, but they work fine.

I have a pair myself but haven't fitted them yet, hope to get a spare bit of time at the end of the month.

Peter


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## simbadog (Jul 12, 2011)

Had one of these on my yacht, great bit of kit 

http://www.nasamarine.com/proddetail.php?prod=BMN-1_Battery


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## namder (Sep 20, 2006)

Had one of these on my yacht, great bit of kit

http://www.nasamarine.com/proddetail.php?prod=BMN-1_Battery


> How can these be fitted permanently as the instructions state that nothing can be connected to the negative terminal.
> 
> If the above is incorrect, can this be fitted to a pair of batteries.
> 
> John


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## cabby (May 14, 2005)

Thank you Peter for filling out my response with fuller information.However I really do not think either is really of great need in a motorhome. Maybe the OP can enlighten us on this.

cabby

just read this and hope this is not taken as a critisism.


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## simbadog (Jul 12, 2011)

namder said:


> Had one of these on my yacht, great bit of kit
> 
> http://www.nasamarine.com/proddetail.php?prod=BMN-1_Battery
> 
> ...


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## PaulW2 (May 30, 2010)

I've got one of these. Very useful bit of kit.

http://www.transplanet.fr/boutique/info_produit.asp?num=9426


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## simbadog (Jul 12, 2011)

You've got me thinking now & I looked on another boaty forum & someone has fitted some of these :idea:


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## cliffhanger (Jun 27, 2008)

namder said:


> Had one of these on my yacht, great bit of kit
> 
> http://www.nasamarine.com/proddetail.php?prod=BMN-1_Battery
> 
> ...


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## listerdiesel (Aug 3, 2012)

cabby said:


> just read this and hope this is not taken as a critisism.


Not at all! 

Peter


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## subfiver (Oct 15, 2011)

No-one's mentioned Smartguage, so I will:
Smartguage

Only does the one thing, but does it well - not cheap tho'. Read the bumf on the website ...

Got one on the boat (10x130ah domestic battery) and was so impressed put one in the camper too (2x110ah). Need an ammeter in the camper yet so I can see the amps in/out.


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