How to find a battery drain?

[RipGroove]

I'm pretty sure ever since I fitted a Puig tail tidy, genuine Yamaha LED flashers and an eBay flasher relay something is is slowly draining my battery. If I don't use the bike for a week or two it really struggles to start if at all. Currently it's constantly plugged in to a battery tender but I need to get to the bottom of it.

I'm a bit of a noob when it comes to electrics, I'm pretty sure I installed the tail tidy and indicators correctly though as they are pretty much plug and play. But when it comes to electric fault finding I'm useless.

Here's what my battery currently looks like with the key out of the ignition, do I even have the meter on the right setting? I think I have it set to DC 50v and that its reading about 11v?

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[stumpy66]

can you not unplug one item at a time, my first bet would be the relay, could be sticking?

 

[RipGroove]

can you not unplug one item at a time, my first bet would be the relay, could be sticking?

Yeah could be, not sure how to test it though TBH? Pretty sure I need to connect the multimeter in between the negative terminal on the battery and the bikes negative lead in order to measure the bikes drain but what setting should the multimeter be on?

Assuming I can set the multimeter correctly to read the drain, could I then just unplug the relay and see if the reading goes down to confirm if it is actually that? And if not then I'll unplug the indicators and see what happens.

 

[RipGroove]

Got my digital one out, battery measures 12.7v with the ignition off.

Not sure if I'm doing this next bit right but with the multimeter in series between the negative terminal on the battery and the bikes negative lead it reads 12.3v (does that mean my bike is constantly draining 12.3v?)

And it does not change when I unplug the flasher relay, tail tidy and the indicators. And those are the only electrical mods I've done to the bike.


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[RipGroove]

OK it seems I need to have the multimeter set to Amps in order to check for a battery drain. So I've done this (with my digital meter, not the meter above in the photos as I don't think that one does Amps) and connected it in series between the bike and the negative battery terminal. And got a reading of zero, I then switched the multimeter down to 200mA and still got a reading of zero so surely this means there is no drain? I'm a bit dubious of a reading of zero as surely there should be some small drain for the dash memory?

So with that in mind I've taken a Volt reading across the terminals of the battery and written it down (12.66v) and I'll check it again every day for a week (without the bike being ridden or charged and without switching anything on to see if I am actually loosing power over time.


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[stumpy66]

That sounds like a plan, might sound daft but is the battery itself ok, even if its a new one could be dodgy?

 

[RipGroove]

That sounds like a plan, might sound daft but is the battery itself ok, even if its a new one could be dodgy?

TBH I don't know.

 

[Triple Trouble]

Sometimes the cca's drop but the bike will start ok when it's warm??? Just a thought.

 

[Martin p]

hiya , you are doing the right thing putting the meter between the neg term and the battery, i work on cars and a12 volt system is a 12 volt system. A good reading would be 0.07 amp or less ( 7 hundreath of 1 amp) even better get an amp clamp, then it saves you disconneting the negative lead. Hope this helps

 

[RipGroove]

I've been testing and when my multimeter is set to 200mA on the dial it reads 00.4 when connected in series between the negative terminal and the bikes negative wire which I'm guessing is 4mA (as I noticed when going from 20A to 200mA on the dial the decimal point moved so it's now reading milliamps and not Amps).

So if that's the case then 4mA is an acceptable amount to be drawn from the battery with the ignition off. This small amount is probably to keep the dash memory alive.

Also with the meter still in series between the negative terminal and the negative wire (still reading 00.4) I systematically unplugged everything I've added to the bike (tail tidy, indicators, indicator relay and USB port) and the reading on the meter stayed the same.

So taking all that in to account and assuming I'm reading the meter right (4mA) it looks like I don't have a battery drain at all, so now I'm thinking the battery is fucked. So it's currently on a trickle charger ready for when my battery drop tester should arrive (tomorrow I think) so I can see if the battery is actually any good. I'm told the drop tester has a big old resistor in that simulates the battery being under load which will then tell me what I need to know.

I did a crude load test with my multimeter this morning:

Battery read 12.64v to start with so I started bike with meter across terminals and the voltage dropped to 9.46v (I'm told anything under 9.5v and the battery is shagged), so I went to do the same test with my second analogue meter just to compare and the bike wouldn't start, not enough juice in the battery.

So I'm hoping it's just the battery that's fucked as I'm also told that a fucked starter motor can give the same symptoms as a weak battery.




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[RipGroove]

I'm no sparky at all so can anyone tell me why/how my battery seems to measure OK with regards to Volts but at the same time not be able to start the bike, can a battery charge and keep volts but somehow loose it's Amps?


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[PaulG]

A battery needs to have a very low impedance (internal resistance) to be able to supply high current.If some fault has increased the impedance the current will be limited and the battery won't turn the motor over.The voltage across the terminals won't show this.When automotive batteries fail it is usually in this way.If the voltage has dropped,then a cell may have failed.

 

[Triple Trouble]

*TUT*.....
I was just gonna say that.....!

 

[RipGroove]

Battery tester arrived and I'm pretty sure my battery is fucked.

Charged battery for at least 24hrs, results:

No load (12.8v)

Load applied, needle started just inside the WEAK section and quickly moved to BAD:

With the load off again the needle quickly went back to 12.8v so according to the instructions that indicates a knackered battery:

I need to order something today on 24hr shipping so my options are pretty low as the bike has to be functional ASAP so as I haven't got any time to research a better lighter alternative I've had to get another Yuasa one.

That said though I've read reviews on Yuasa and they seem highly rated and are supposed to last years if looked after.

So I guess I killed it by leaving it in the cold garage over the Winter and not starting it enough, I probably should have hooked it up to a battery tender over the colder months when the bike was not in use. Hopefully that's all it is and I haven't actually got a parasitic battery drain that for some reason I can't detect.


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[bobh]

Best thing if you are storing the bike for more than a month or two is to disconnect the battery, or take it out and keep it somewhere where you can give it an occasional charge. OK, you lose all the trip info, time etc.

Alternatively, if the garage has a window with some daylight, hook it up to a solar charger. I used one of those (the very basic one that I got from Maplin's, though Oxford re-badge them and sell them at a higher price) for several years on a bike that had a Datatool alarm. It still had the original battery when I got rid of the bike at eight years old.

Starting the bike takes quite a drain, and needs a run of a few miles to top the battery up again.

 

[Mark Cousins]

I got one of those oxford solar panels, pretty useless if you ask me. Had mine connected all winter and they are supposed to keep a charged battery charged. Three times mines gone flat now

 

[kernow]

I have had great success using a solar panel to keep both my car and motorcycle batteries topped up in a lock-up garage without electricity. Basically around two and half years ago I bought a solar panel off ebay for less than 30-quid along with a controller, which is absolutely essential, for a further 8-quid. It measures approx 600mm x 450mm and has an output of 20watts, it's also waterproof so it's mounted outside on the back of my lock-up at a 45-deg angle. I have it connected to my car all the year around, and occasionally I swap it over to my bike to top it up, in two and a half years I have had no-issues whatsoever. The reason for the controller is despite only being a 20watt output on a very sunny day it can overcharge so the controller stops this from happening, also overnight when the panel obviously doesn't work stops it from reverse discharging.