I’ve had a problem over the last 2 years. Had new alternator 2 new batteries ( last one a varta 4 weeks ago) . Couldn’t detect any drain despite doing the usual pulling of fuses etc. Had an “ auto elec “ last year who said duff battery, I’ve had 2 since then ! Any way watched a you tube video and just bought an amp clamp. Both engine and leisure batteries charged up and I put the clamp on the + terminal. Engine battery showed drain of 20 m/a . Leisure showed 1.2 amp drain. I have a Diatec? Sp. split charger that blew its fuse about 12 months ago and at the time was continually clicking on and off, this has stopped but could it be the problem? On the leisure side when tested nothing was on. Also on leisure I only have 2x 12 v lighter sockets to power very light weight stuff. Can’t imagine where a 1.2 a drain could come from…..confused and electrically challenged. Any input welcome as always.
I found that my Propex was draining current whilst switched off - it seems to be in standby mode - and my leisure battery would be flat in a day or two when nothing else was on.
1.2A is a large current. Just unplug everything connected to it one thing at a time, including your VSR if you’ve got one. Something must be doing it… Also, DC clamp meters can be quite fussy, so may not be telling the exact truth.
Had totally forgotten about the Propex, thanks I’ll put it on the list. My problem however is engine battery but if the split charger is bgd then this could ? be an issue. Thanks
Yes, the clamp I tested on various cables in house , toaster, iron etc and it was a bit hit and miss, but when I went to DC on the engine and leisure batteries it seemed pretty constant. And to drain a 75 a/ h New Varta battery in 10 days after a 300 mile trip it must be a big draw! Not sure what VSR is but only thing connected or capable of connection is 2x 12 v cigarette sockets , a few led lights, and ( as Cunny 44) says possibly my propex. Only other modern thing is a dash radio which I only works with ignition on. Could a duff split charge relay draw 1.2 a?
I'd agree about the propex, but I'm not sure mine drew that much - seems a lot, so it's probably not the whole problem. (I have since put an on/off switch in line between the battery and the propex controller so that I can actually switch it off when not in use. The reason for it being permanently live, is the fan needs to run on after the gas / spark etc is turned off, so that the unit can dissipate it's heat - so as long as you let it do this before cutting the 'main switch', it's a good solution)
Same for an Eberspacher. If you don’t allow them to do a cooling cycle, they melt. Well, maybe not melt.
If the split charge relay is duff, could it be trying to charge the leisure battery constantly? In the same way that it would if the alternator was feeding power with the engine running, but with the engine off it’s still doing it and pulling the juice from the starter battery instead. Assuming the leisure battery is larger than the starter, I’m guessing the starter would get killed. If you put a multimeter on the leisure battery, then disconnect the split charger, if you see a drop then I’m guessing it’s getting trickle charged even with the engine off?.. well that’s my theory and I’m sticking to it until someone who actually knows what they are talking about comes along.
Although I have no real idea what you are talking about I see where you are coming from I leave my van on the drive connected to a 240 v hook up to an internal Sargent “box” that I think has the charger gizmo in it. There is then a Diatec . Sp split charger. When mains are connected then both batteries show 13.6 v. Pretty constant. Went away last week for a week, hook up on site, no problem. Came home , didn’t put 240v input on and after 10 days with NOTHING connected ( other than possibly Propex see Cunny 44 above) The leisure showed 12.6 and engine battery 12.01. As stated earlier current draw on engine battery negligible leisure draw 1.2 A.
Not wanting to sound sarcastic when i mention youtube , but i thought i had a parasitics drain on my battery , and knowing nothing of electrics i watched a few random youtube videos that were brilliant to explain how to find the culprit draining the power . I learnt hell of a lot . Quite pleased with myself, however as i was passing halfords i called in and they checked the battery to discover faulty cells and replaced under warranty . Ask me owt about parasitic drains now and i know bugger all ,as with all things electrical i empty my brain for more natural knowledge
The way I look for drains is by disconnecting the battery, Then measure resistance between the +ve lead you removed from the battery and earth. It should be open circuit. If it isn't, remove fuses until it is. That will narrow it down to which circuit is misbehaving etc etc. I like this method as no voltage is present, batteries disconnected, no chance of shorting stuff by accident.
1.2A could be a combination of things.. Like my Sony radio draws 0.25A if you leave the fascia clipped on, but with the display switched off, about the same as being on and playing music quietly. USB chargers in 12 volt sockets may also be draining a bit. A previous owners car alarm you lost in the wiring...
Get your trusty meter out. Set it to, say, 10A DC current range. Swap the leads to the current measuring position. Undo your battery earth strap, connect one lead to batt -ve, the other to the earth strap so the meter's in series with the battery supply. Then you can measure the current more accurately. When you're done, switch the leads back to the "volts" position, or it'll go bang the next time you poke it into the kitchen lights
Also with the disconnection of the battery, some electronics will not "wake up" with just test meter power applied to the battery leads, so the resistance you see can be much higher than the about 10 ohms that the 1.2 amp drain indicates.
