Gunson battery checker question

[peter2407]

Any one got one? Juts had a battery tested and it showed green and yellow at c. 12.2 v. Charged the battery with a halfords special that continues to show charging (as opposed to trickle charging). Using a voltmeter, I am getting 13.3 v . Apply the Gunson (G4184) and it intially showed c6 on the display. I think the c6 was actually CB and there may have been another character but I missed it. The next test of the Gunson showed Green and Yellow but I dont understand why it would continue to show Green and yellow and the Halfords charger not showing trickle charging. Any ideas? In the meantime I will disconnect the charger measure the voltage and check it again in a week or so.

 

[VicS]

Any one got one? Juts had a battery tested and it showed green and yellow at c. 12.2 v. Charged the battery with a halfords special that continues to show charging (as opposed to trickle charging). Using a voltmeter, I am getting 13.3 v . Apply the Gunson (G4184) and it intially showed c6 on the display. I think the c6 was actually CB and there may have been another character but I missed it. The next test of the Gunson showed Green and Yellow but I dont understand why it would continue to show Green and yellow and the Halfords charger not showing trickle charging. Any ideas? In the meantime I will disconnect the charger measure the voltage and check it again in a week or so.

Not clear which Halfords charger you are using or if its an automatic one or not.

Under what conditions are you measuring the volts you quote. While charger still connected, after resting with no charge or discharge for 12 hours or so, or what? ( its not charging other than very slowly at 13.3 but once disconnected from the charger it should fall very quickly to less than that, say to around 12.9.

CB indicates battery requires charging if the volts are below 12.3, or to reduce the volts and retest if over 13.2

Yellow + green = OK but weak.

No knowing what some of these automatic chargers get up to makes it difficult to interpret what you are seeing. ( I have just been playing with Lidl's cheapie..... I think I have it sussed but does not behave how I expected it to)

If I were you I would disconnect and switch off the charger . Then reconnect and switch on and leave it charging for a good while ( it may step down to a very low rate like the Lidl one does) before restesting with the Gunson

For anyone else's benefit Gunson instructions at http://www.gunson.co.uk/items/pdf/Products/G4184_ins.pdf

 

[peter2407]

VicS

Its one of these http://www.autoexpress.co.uk/accessories-tyres/42774/halfords-fully-automatic-battery-charger

Voltage tested with a separate voltmeter directly after disconnecting the charger. One point though your comment was retest if over 12.3. Isnt it 13.3? ie I have overcharged, which I dont understand if this is fully automatic?

I will disconnect and then retest but thanks for the help thus far?

 

[VicS]

I am hoping to find the instructions for the charger but whats on the website is not the same as the one in your link!

My mistake on the volts ...... trying to read it side ways on the screen, but found the rotate control now. "reduce volts and retest if over 13.2". Now corrected.

Id not be overly surprised by a reading of 13.3 very briefly immediately after coming off charge but would not expect it to stay there for long.

Might be worth checking the battery in your multimeter . They can over-read if the battery is getting low ... at least the cheap ones can


All I have found in the way of instructions for the charger is a close up of the back of it.... where it says read the instructions!

 

[peter2407]

Thanks Vic. You are right - within 15 minutes of taking the charger off, the voltage had dropped from 13.3 to 12.8. I will measure it again in a few days. Thanks.

 

[VicS]

Thanks Vic. You are right - within 15 minutes of taking the charger off, the voltage had dropped from 13.3 to 12.8. I will measure it again in a few days. Thanks.

If it stays up around 12.7 for a few days you know its holding its charge reasonably well. A good battery with no load should take several weeks to fall below 12,5.

While you are getting a yellow + green indication on the Gunson it's capable of supplying the high current required for engine starting.