battery charged

[Rich06FJR1300]

upon finding i had a dead battery yesterday, charged it up...decided to see what the current draw is when the bike is off....got 0.008 amps when shut off (that's with the voltmeter on), after a minute the chargeguard voltmeter shuts off and it goes down to 0.005 amps....is that acceptible? I seem to remember no more than 0.001 amps after the bike is shut off.

 

 

thanks,

[powerman]

how are you measuring that small of a current acuratly?

did you or can you zero the meter?

also you can pull fuses and see if changes.

I would assume the RID clock is the only current draw unless you have the radio.

let us know what you find

[90RedRider]

Electrical things are my lowest apptitude when it comes to working on bikes. So for my learning, how do you go about measuring this draw, and what is that showing you. I'm guessing it's how much juice your systems( the clock and ?? )are drawing off the storage capacity of batt. so hoping I'm not a complete elec. dope.So how do you measure that and is this just to determine if it is excessive and something additional is draining the batt.

[nrp]

Any number of simple $10 - $20 analog multimeters can measure currents this small on the right range. The trick is to short the meter out when first connecting it so that the initial current surge doesn't blow anything (on the meter) when it is first connected up & turned on.

 

IIRC my 2000 R1100RT takes a little more current in standby - about 30 milliamps.

[powerman]

Any number of simple $10 - $20 analog multimeters can measure currents this small on the right range

they maybe able to measure a current, but at what acuracy, that is the question? There is a big difference between 8ma and 1ma when it comes to draw down of the battery. lets assume 8 ma draw with a 8 amphour battery. the battery would be drained in 1000 hours. at lower 1ma draw then the battery would last to 8000 hours which is a big difference in time. so at 8 ma it will dead in say 4 to 5 weeks were the lower discahrge should last many months. Note this discussion does not included self dischagred and increase in capacity due to the low rate of discharge.

[nrp]

IIRC self discharge on a lead acid battery is about 1%/day. Ordinary analog meters can measure the current within a couple percent of range or ~5% of reading whichever is less. A little extra charge rate (say 20 ma) isn't going to hurt anything over a season.

 

I suspect many of these trickle chargers posted by others are putting out say 1/2 amp or more, which will cook a small battery over an extended time. The real problem is not measuring the charge rate to at least get it in the right ball park. If it is excessive, I sometimes use a 24 hr light timer to turn it on for only the appropriate fraction of each day.

 

On another unrelated posting (RST Electronics) I have read about pulse type battery chargers that are good for preventing sulfate buildup problems. They hit the battery with a high current pulse (like 5-10 amps) for only about 2 microseconds long, about 70 times per second. The average current is still less than ~30 milliamps on the prototype I built, but it exercises the battery. This is the first winter I have tried it. We'll see how it goes.

[Rich06FJR1300]

I have a digital multimeter...set it for DC amps and the lowest setting (in this case to 3 digits). I found out it was my voltmeter on the bike (the chargeguard) of all things...you hook the meter up in series to the negative terminal on the battery....so basically you remove the ground terminal and put the meter in between the ground terminal the battery...i measured 5 milliamps draw with the volt meter connected (and it was off!) then i removed the shunt that is supplied with the chargeguard...walllah!!! less than 1 milliamp draw (that's the way it should be). So i'm pondering the idea of dumping the whole chargeguard farkle as its more trouble than its worth. Though i had the chargeguard hooked to the negative and positive side of the battery...i could run a lead from the positive side to a relay...that should solve that problem of the excessive draw when the bike is turned off.

[Ken H.]

So i'm pondering the idea of dumping the whole chargeguard farkle as its more trouble than its worth.

Yup, I'm wondering the same thing. My aux. temp/voltage/time display is live all the time so I can glance at it once in awhile as I walk by the bike (here in the dead of winter ) and see how far down the battery is, but it itself is probably what's taking the battery down over time the fastest!

[bmwmick]

upon finding i had a dead battery yesterday, charged it up...decided to see what the current draw is when the bike is off....got 0.008 amps when shut off (that's with the voltmeter on), after a minute the chargeguard voltmeter shuts off and it goes down to 0.005 amps....is that acceptible? I seem to remember no more than 0.001 amps after the bike is shut off.

 

 

thanks,

 

The acceptable battery current drain on an R1150RT is listed as 2.6 ma in the OFF position and 3.1 ma in the R (or accessory) position. This assumes there is no alarm system attached.

BMW recently issued an SI on the procedure to measure battery drain on all their current models. SI# 61 001 06(003)

I believe they are investigating 'flat' batteries on the newer CAN bus bikes.

 

Mick

[wolcott]

forgive my ignorance, what the hell is a "chargeguard voltmeter"?

[Ken H.]

ell is a "chargeguard voltmeter"?

Kisan chargeGuard

[RFW]

upon finding i had a dead battery yesterday, charged it up...decided to see what the current draw is when the bike is off....got 0.008 amps when shut off (that's with the voltmeter on), after a minute the chargeguard voltmeter shuts off and it goes down to 0.005 amps....is that acceptible? I seem to remember no more than 0.001 amps after the bike is shut off.

What are you measuring current with? How accurate is it in the first place? At the level with a typical cheap DVM your measurement error can easily be a couple of mA.

 

A 5 mA drain on the battery (or 0.005A as you refer to it) is peanuts. If this is ALL that is being drained from the battery when the bike is off, then this is quite obviously not significant.

 

For example, if you have a 25 A-H battery and a 5 mA drain it is pretty clear that it will take 5,000 hours to drain the battery flat. That's OVER 6 MONTHS! In fact, the self discharge of the battery itself is higher than this!

 

I don't know where you got the idea that anything over 1 mA current drain is a problem, but that is wrong. It is typical for the electronics systems in a modern bike or car to draw up to 10 mA whan the vehicle is shut off.

 

Bob.