Voltage drain

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31 Oct 2012 19:45 #1 by dandjcr
dandjcr created the topic: Voltage drain
Forum Home > OKA Maintenance > Voltage drain

Greg #210 and Dean #366
Member
Posts: 58
#210 Has been to auto electrican today we have found that we have a drain of about .2 amps not much but enough to kill batteries over a few days. Already have isolator fitted but would like to find where its goin ans why. Any pointers?
April 11, 2012 at 5:46 PM Flag Quote & Reply

Peter & Sandra James Oka 374
Member
Posts: 412
Stereo memory, clock, if you have a smart solenoid or DC to DC charger they also drain a small amount even when "off".
--
Oka 374 LT Van

April 11, 2012 at 6:18 PM Flag Quote & Reply

oka422
Member
Posts: 7
A current of 0.2A should not discharge a OKA battery in a few days, it should take a few weeks or longer. Either your battery is dying or your battery is not being fully charged or you have an intermittent heavy load such as a fridge connected.
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Roger -- OKA422



April 11, 2012 at 6:56 PM Flag Quote & Reply

Moose2367
Member
Posts: 110
Mine does the same thing. The only thing drawing power is the clock, gotta be going somewhere else though. Has a redarc isolator, which works.
I have just installed a reversing camera and the screen has power to it all the time as the buttons are lit, but ti was going flat before i installed it.
Robin did say it would go flat after a few days or a week when i bought it, will be checking thouroughly when the cab is off soon.
April 11, 2012 at 7:09 PM Flag Quote & Reply

Dandj
Member
Posts: 367
Do you have an inverter connected to a battery?
They can have a standby current of around 0.2A (see Jaycar 400w inverter specs) by just being connected but switched off.
Also radios/cd players on standby can consume a surprisingly high current.
Central locking/alarm systems? Any spike suppression devices connected directly across the battery? They also consume power all the time.
A single 10w or more solar panel would replenish this amount and keep the batteries topped up and is cheaper than a new battery.
--
David and Janet Ribbans, Oka 148

April 11, 2012 at 7:17 PM Flag Quote & Reply

Dandj
Member
Posts: 367
Greg, if your Oka was previously owned by a tour company, did it have a PA or intercom system fitted, or a speed limiter system? Both might take current when off.
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David and Janet Ribbans, Oka 148

April 11, 2012 at 7:42 PM Flag Quote & Reply

Tony Lee
Member
Posts: 539
"A current of 0.2A should not discharge a OKA battery in a few days"

0.2 A is 4.8Ah per day which would totally flatten a 100Ah battery in less than 3 weeks.

My vehicless sit unattended for up to 2 years so have fitted some way of charging the engine batteries from the house battery solar system. One vehicle has a dual battery solar regulator which gives 10% of its output to the engine battery. Two have home made Schottki diode feeds from the house to the engine battery and the OKA has a TrikleStart unit (about $40 in the US) which, once the house batteries are sitting on float, deliver up to 5 amps to the engine battery if required. I leave the battery connector on so both batteries stay charged.
--
Tony

picasaweb.google.com/114611728110254134379

April 11, 2012 at 10:13 PM Flag Quote & Reply

Jeff & Roby OKA379
Member
Posts: 6
I assume that your OKA is a bus configuration as it came from a tour company. If it is like ours you may find that the solenoid that operates the air step draws a small amount of current continuously. We have a permanently fitted battery charger for the 'house' batteries plus a small CTek for the starting battery. Hence, no problems.
--


April 12, 2012 at 6:55 AM Flag Quote & Reply

Hank Onthewater
Member
Posts: 79

Hi Greg & Dean
You said “batteries are killed in a few days” That is 2 or more batteries, being on average 100 Amp/hr each and being killed/flat meaning not able to start engine? You have lost at least 150 of 200 Amp/hr. 150 amp/hr in 48 hours is a ‘loss’ or drain of approx. 3 amps. If you measured 0.2 Amp, then there is another drain as well, or your batteries need replacing.
Therefore, check the condition of BOTH batteries,separately, and not while they are switched in paralel.
Yes, you could install chargers, and solarpanels so the fault(s) becomes more invisible, but all you are doing is address the symptoms, not the cause.
A question: would you like to go bush with batteries that drain themselves, or getting drained in a few days?
If both batteries are good, than by all means check each of the items as mentioned in previous posts for excessive drainage, but in my experience clock, radio, electronic isolators, DC-DC converters use all amps in the magnitude of few milli amps, and as Roger said “ will take weeks (or in my view even months) to drain one good battery.
I am not aware that the solenoid ofthe airstep uses power. Not on my van that I have noticed. But will measure.
Spike compression? They may use afew milliamps, but there are cheap ones on the market, that may blow a component, and so offer a return path for the current.

Can I add the following items that can use current in off orstandby mode? Solar-control unit; in fact many electronic devices use some current in standby or ‘off’ mode. But in most cases always in the order of milli amps.
The following can also contribute to an unwanted drain: LED panelmeters that are always ‘on’, up to 100 mAmp each, LCD panel meter 10-50 mAmp, a switchboard with indicator lights, up to 100 mA for each light. If these are LED lights, 3 to 20 mAmp each.
Finding the offending part? Get yourself a day off, ample supply of coffee, and a packet of biscuits. A bar of chocolate will keep you in a good mood as well. Put up some good music, but do not use the radio in theOka. Work systematically, writing down what you have checked (some of us are at an age that memory fails, like batteries do).
Get yourself a multimeter, set to 10 Amps DC, in series with the battery. Do I need to say not to try to start the engine this way, or to switch on lights etc? If you happen to fry the multimeter that way , get another one, they are cheap enough. If the drain is a lot less than 10 Amps put the multimeter to a lower range if it is not auto range model.
And start pulling fuses, or to disconnect wires. Having a wiring diagram might help. However I would start checking the items that are added on to your Oka, as 90% sure that is where the problem lies, not in the basic wiring of the Oka, unless a fault has developed.
After a day with biscuits and chocolate and no result, go to plan B: remove multimeter, get a bottle of wine, and leave OKA overnight whilst sampling the liquid and damning electrics. Continue next day with more chocolate, and turning up the music louder and if needed, activate Plan B. again. Repeat this process until source of drain is found, hopefully before the health of your liver becomes a more important issue than battery drain.


April 12, 2012 at 9:35 AM Flag Quote & Reply

Tony Lee
Member
Posts: 539
Another way to do some checks that may get the info without major disconnects is to pull each fuse out separately, and connect the multimeter (on DC amps range) probes across the fuse socket, one probe on each side. That will show the current drain for that circuit.

Problem may lie with DIY stuff that has been added and not fused, or fused from weird locations.

All the little loads add up. I know at night in my MH, it looks like luna park with all the things that have little pilot lights and dials glowing away in the dark. One favourite one for motorhomers is a wired in LPG alarm. Often 100mA, it doesn't take long to flatten batteries, especially if the weather is hot and a high battery self-discharge rate is also working against you.
--
Tony

picasaweb.google.com/114611728110254134379

April 12, 2012 at 10:21 AM Flag Quote & Reply

Peter & Sandra James Oka 374
Member
Posts: 412
Hey Ttony we've got one of those, also detects CO2 but it does make a nice night light, lights up the floor really well for the niddle of the night loo visit.
--
Oka 374 LT Van

April 12, 2012 at 7:45 PM Flag Quote & Reply

Tony Lee
Member
Posts: 539
No LPG in the OKABox so no LPG alarm. Do have separate CO and photoelectric smoke alarms though.
Only time the LPG alarms have been of any use was when some booze bottles got tipped over and there was an occasional drop falling on the floor next to the alarm. Took a while to work out why the alarm was going off but it did save wasting a litre of Bundy Rum.
--
Tony

picasaweb.google.com/114611728110254134379

April 12, 2012 at 9:36 PM Flag Quote & Reply

Greg #210 and Dean #366
Member
Posts: 58
Hank have taken your advise got a bigger battery have increased the intake os home made scotch. All is well their are no problems we can not over come with help! and good MATES.
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April 13, 2012 at 5:46 PM

David and Janet Ribbans - Oka 148
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