Looking for a cheap digital voltage display for my LB

mikeonb4c · Post by **mikeonb4c** » Tue Sep 25, 2007 5:33 pm

Can anyone offer advice.

I'd like to put a switch in the circuit that supplies power from my leisure battery. I wondered if having a digital voltage readout when the switch was 'on' might also be handy as it would give me an indication of how much juice was left in the battery (and thus warn me before deep discharge caused the 25amp fuses in my corblimey VSR circuit to blow when the charging circuit attempts to recharge it). I've seen this on ebay:

http://tinyurl.com/26vuz7

But I'd have thought there was some cheaper device that would do the job. Anyone know if this kidn of device can be had at a cheaper price (I like the way this one can be powered from the same source it is measuring).

Any advice on the logic of the above and on sources for a cheap voltage meter would be appreciated. Thanks chums.

Mike

Ralph · Post by **Ralph** » Tue Sep 25, 2007 5:50 pm

Maplins may do something to suite, or what about
filleting one of the cheap multi meters ?

Rough guide to battery condition this is standing with no load or charging

12.7v or over 100% charge
12.5 75%
12.4 50%
12.2 25%
12 or under Flat

I use one of those led battery indicators that plug into
the cig lighter and plug it into the one in the back connected
to the leisure set up.

pippin · Post by **pippin** » Tue Sep 25, 2007 6:01 pm

That's not a bad price Mike, apart from the P&P.

I installed something similar in my Bongo with a centre off two position momentary switch so that I could measure the voltage of the engine and leisure batteries.

Cost me a bit more than that but it is similar in function.
It is very handy in that it is powered from the suource that is being measured.

The LED thingies are OK, but there is nowt quite like knowing the actual voltage.

trevd01 · Post by **trevd01** » Tue Sep 25, 2007 6:47 pm

Techie? or Wanted?

...moving to Techie

mikeonb4c · Post by **mikeonb4c** » Tue Sep 25, 2007 8:00 pm

Thanks for the excellent tips guys - much appreciated. You've convinced me that a digital voltmeter is a sensible idea. I also wondered about the 3-position switch engine/leisure battery idea but had bought a simple rocker switch by then. I suppose the engine battery will tell you directly if it has got flattened!

I considered putting the topic on 'Techie' but thought as it wasnt hardcore Bongo technical stuff that I'd put it on Bongo chat. But fine with me either way!

Post by **aitch** » Tue Sep 25, 2007 8:46 pm

i also have an led thing with three outlets that lights up red, green or yellow give me some idea of the state of the leisure battery whilst camping or on the move but would agree a volt meter is the only true gauge of what is going on at any one time.

Ralph · Post by **Ralph** » Tue Sep 25, 2007 9:00 pm

You also have to take into account that if the leisure
battery is in the back like mine in the Mazda kitchen
unit, due to the length of the cable run it is not going
to reach the same voltage as the front mounted batteries
fed by much thicker leads.

bigdaddycain · Post by **bigdaddycain** » Tue Sep 25, 2007 10:55 pm

That's a good point ralph, perhaps the best location for the battery indicator would be nearer to the power cables ultimate destination, as opposed to its source...

Post by **Simon Jones** » Wed Sep 26, 2007 8:20 am

I've just ordered several meters off eBay including this one which is powered by the supply it is measuring i.e. it only has 2 wires:

http://cgi.ebay.co.uk/Blue-LCD-Volt-Met ... dZViewItem

I used to work for a supplier of digital panel meters, so am fairly happy to make any modifications if required. If anyone is planning on buying a cheap multimeter & attempting to re-package it into a smaller box, dont bother. The LCD is connected to the PCB by what are known as elastomers which are like pieces of rubber with conductive strips embedded in to make the electrical connection. The case is integral to keeping all the pieces lined up to make the connections and without it, you just have a pile of useless bits!

smartmonkey · Post by **smartmonkey** » Wed Sep 26, 2007 1:00 pm

Well digital is all very well but it's so yesterday. What you need is a nice set of analogue gauges including an 11 to 14 volt meter. Just think of the number of gauges you could have lined up - main batt, aux batt, oil pressure, oil temp, water temp, air temp, head temp, handbrake temp, ext temp, internal temp, exhaust temp, boost pressure and a few more temp ones. Its' got to look much better than a crummy digital.

mikeonb4c · Post by **mikeonb4c** » Wed Sep 26, 2007 1:06 pm

You are right of course SM. Problem is (apart from the £ issue) that I think the digital one in question would probably fit very nicely in the recess just above the fuse box, with a switch next to it but I cant think how to hide away a (circular) analogue device similarly

mikeonb4c · Post by **mikeonb4c** » Wed Sep 26, 2007 1:18 pm

Simon - thanks for that link - cheaper than the one I'd found so will probably follow that up. A pity they dont do the model your link shows, but with green readout - they do a green one but different style/dimensions.

I'm starting to sound like SM now!

mick · Post by **mick** » Wed Sep 26, 2007 2:07 pm

The link below is for the green LED - slightly different style, but good price

http://cgi.ebay.co.uk/Green-LED-Volt-Me ... dZViewItem

mikeonb4c · Post by **mikeonb4c** » Wed Sep 26, 2007 2:14 pm

Thanks mick - I'll follow that up.

Mike

pippin · Post by **pippin** » Wed Sep 26, 2007 6:38 pm

Should not this thread now be moved over to "Pimp my Bongo"?

pippin -stop stirring!