How to monitor how much charge in LB

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hembramacho
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How to monitor how much charge in LB

Post by hembramacho » Sun Sep 27, 2009 8:12 pm

Our leisure battery ran right down over the weekend - few reasons have been pondered over and possible/probable reason is a faulty LB, which is under warranty so changing it won't be a problem.
We have a Willinton split charge relay and were only running the 12v compressor fridge and had the cabin lights on. Granted the lights were on for longer this trip as it got darker sooner but I can't see having them on a couple of extra hours would cause the battery to run right down. Also when I started the engine the lights and fridge sprung into action which makes me think the split charger is working fine and the fault is with the actual LB.
Anyway, my thinking for the future is a way to monitor how much juice is left in the LB would be handy - something simple like the fuel guage (Full - Empty) would be fine for my needs.
Has anyone got anything like this that they could recommend - I know you can get devices that plug into the cigarette lighter that tell you the state of the battery but something wired in I feel would be better in the long run.

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Re: How to monitor how much charge in LB

Post by GICarey » Sun Sep 27, 2009 8:23 pm

Believe voltage read-out will scale with power left in battery, as it does for normal AA cells, etc (this is how devices know how much they have left), so a simply volt-meter would give you a way to test it, just need to know what voltage it reads out when "full" and what it reads out when the power left in it is starting to wane (lights dimming etc).
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Re: How to monitor how much charge in LB

Post by g8dhe » Sun Sep 27, 2009 8:23 pm

The trouble is the only easy thing to monitor on a lead acid battery is the voltage and this really doesn't give an accurate information about the state of charge in the battery. As the battery ages all sorts of extra chemical reactions take place that will cause confusion :-( The best method is to monitor the current flows into and out of the battery and from this you can derive the Amp/Hr charge state, but even this needs to be "reset" occasionally to allow for various charging inefficiencies. There are some single chip solutions available but I haven't heard of them being packaged up into a third-party add ons yet.
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Re: How to monitor how much charge in LB

Post by mikexgough » Sun Sep 27, 2009 8:24 pm

I have not got anything to monitor my LB, I used my Compressor fridge,TV & Satellite as well as the interior lights for 2 nights with no bother last week which is no different from all the other times I have gone without Hook Up I have a 110 AH LB and my Fridge consumption is 12 to 15 amps per day so plenty of juice left for the lights etc...... how old is the battery?
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Re: How to monitor how much charge in LB

Post by lizard » Sun Sep 27, 2009 8:25 pm

Last edited by lizard on Sun Sep 27, 2009 8:27 pm, edited 1 time in total.
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Re: How to monitor how much charge in LB

Post by missfixit70 » Sun Sep 27, 2009 8:26 pm

This thread may be of help Andrew, always good to know what's going on, not difficult to fit a cheap digital voltmeter - http://www.igmaynard.co.uk/bongo/forum/ ... er&start=0
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Re: How to monitor how much charge in LB

Post by hembramacho » Sun Sep 27, 2009 8:32 pm

mikexgough wrote:I have not got anything to monitor my LB, I used my Compressor fridge,TV & Satellite as well as the interior lights for 2 nights with no bother last week which is no different from all the other times I have gone without Hook Up I have a 110 AH LB and my Fridge consumption is 12 to 15 amps per day so plenty of juice left for the lights etc...... how old is the battery?
The LB is 85Ah (I think :oops: ) and is brand new, which makes me think it's a faulty battery.

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Re: How to monitor how much charge in LB

Post by dreamwarrioruk » Sun Sep 27, 2009 8:41 pm

i have a single led which changes colour as the voltage drops. green ok, orange and red means charge.
simple enough and does not take up a great space. i also use a simple led probe if i want to find out more accurately.
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Re: How to monitor how much charge in LB

Post by hembramacho » Sun Sep 27, 2009 8:48 pm

Cheers for the replys guys.
If anyone's going to Silverdale next weekend or the Bakewell meet in 3 weeks I wouldn't mind a look/chat regarding all of this if that's OK.
The replys have given me loads of info and a solution seems quite easy - thanks again.

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Re: How to monitor how much charge in LB

Post by daveblueozzie » Sun Sep 27, 2009 8:53 pm

i have a simple lcd device that connects directly to the LB with the display in the cab, it tells me what charge is being put into the battery when engine running ,and what it also being taken from the battery when the engine has stopped, i can switch it off and on as needed to check the battery condition.
if your interested i can bring one to Silverdale.
its at the side of the clock in this pic.
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Last edited by daveblueozzie on Sun Sep 27, 2009 10:01 pm, edited 1 time in total.
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Re: How to monitor how much charge in LB

Post by hembramacho » Sun Sep 27, 2009 9:05 pm

daveblueozzie wrote:i have a simple lcd device that connects directly to the LB with the display in the cab, it tells me what charge is being put into the battery when engine running ,and what it also being taken from the battery when the engine has stopped, i can switch it off and on as needed to check the battery condition.
if your interested i can bring one to Silverdale, they cost me £13 so same price to you and i will even fit it .
its at the side of the clock in this pic.
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That sounds ideal - thanks so so much. As long as it tells me when my LB is getting low on charge it sounds as if it's what I'm looking for. Are you still OK to fit my white dials too? The blue lights will match the blue LCD display too! 8)

Andrew

ps the people on this forum are absolutely brilliant - probably been said many time before, but thought I'd say it anyway! :D
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Re: How to monitor how much charge in LB

Post by steviebongo » Sun Sep 27, 2009 9:15 pm

yip i've got one of those but in green to match the rest of the dash,easy to fit as it measures the source u connect to so no need for an external power source.and it was cheap aboot a tenner.Image
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Re: How to monitor how much charge in LB

Post by dvisor » Sun Sep 27, 2009 9:22 pm

Snap :D - but mine was 7 quid :D

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Mine switches on/off from a foglight rocker on the dash
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Re: How to monitor how much charge in LB

Post by MountainGoat » Sun Sep 27, 2009 9:25 pm

I could do with one in Green too Stevie. Where did you get yours from?

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Re: How to monitor how much charge in LB

Post by daveblueozzie » Sun Sep 27, 2009 9:33 pm

dvisor wrote:Snap :D - but mine was 7 quid :D


Mine switches on/off from a foglight rocker on the dash
if you look closley mine is slightly different ,toggle switch .
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