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battery level indicator
Posted: 31 Aug 2006, 23:16
by karl
Hi Just came back from a short trip to the lakes. Ran for a couple of days and the Leisure battery seemed to go flat very quickly. Main battery seemed fine as van started first time. Is there a way of fitting a battery indicator to show condition of L or normal battery?
Posted: 01 Sep 2006, 07:11
by Don-Tucker
Hi Karl
JK do a battery condition indicator for both batteries ,it's J11477 at £21.95.
Simple to wire it says.
Don
Posted: 01 Sep 2006, 07:29
by Dan Wood
Essentially you just need a voltmeter across the terminals of each battery.
You could get a cheap LCD multi-meter (about 5 quid - e.g. Maplin's N20AX), set it to DC volts and then put it across the battery. If you have any 12V sockets (eg. fag lighter) you could connect in there for convenience.
For a more 'elegant' solution you could build your own indicator panel and wire it in. A fairly simple 'red', 'amber', 'green' indicator panel will only require a handful of components. (LED's, resistors and zener diodes.)
Ask if you need the details for this.
The trick with lead-acid batteries is never to let them go flat. They break! As a rough guide:
13.8 volts is 100% charged.
12.6 volts is 90% charged.
12.0 volts is 25% charged.
11.6 volts is 10% charged.
11.2 volts is time to stop using it...
Lead-acid batteries have a fairly 'flat' discharge curve, so it's really only easy to decide whether it is 'full' or 'empty'. The in between values are always a guess!