Clubjazz - Honda Jazz & HR-V Forums

Honda Jazz Forums => Honda Jazz Mk1 2002-2008 => Topic started by: JazzMan2018 on May 09, 2020, 12:13:42 PM

Title: Flat battery
Post by: JazzMan2018 on May 09, 2020, 12:13:42 PM
Hi,

Battery is only about 6 months old

Last couple of weeks it is flat after maybe 3 days of non-use

Looking on-line, appears it could either be battery or alternator or something draining it even when off (parasitic charge)

Plan is to get a meter on it to check a) voltage when not running b) voltage under idle c) voltage under idle & load, to try and isolate it

If no problems found, start removing fuses one by one to isolate which circuit is draining it

Does this sound the right approach?

Cheers
Title: Re: Flat battery
Post by: Jocko on May 09, 2020, 12:24:09 PM
Do you have an alarm fitted? If so that can eventually drain a battery. You say "Last couple of weeks" and "3 days of non-use". To me, this means it has failed to start more than once. Did you fully charge the battery once you got it going or did you just go for a short run or even leave it ticking over? That is not enough to fully charge it.
Does your car have air-con? Have you checked all the interior lights are off, especially the boot?
Title: Re: Flat battery
Post by: JazzMan2018 on May 09, 2020, 01:22:15 PM
Hi,

No alarm

Has a bluetooth receiver in cigarette socket but unplugged that last time so not the problem

Will double check the boot. No a/c

I drove it for 10 miles, around 30 mins. Will idle speed not work or just take longer?

Thanks for the pointers

Title: Re: Flat battery
Post by: Jocko on May 09, 2020, 02:32:27 PM
Cigarette lighter socket is controlled by the ignition switch. As long as the ignition is turned off completely (0 position) before the key is removed (some posters have found they can remove the key in the Aux I position), then the cigarette lighter/power socket in not live.
The best way to charge the battery with the Jazz's charging system is to drive with the lights and possibly the rear screen on. At tick-over or low revs, there is hardly any charging happening.
Title: Re: Flat battery
Post by: JazzMan2018 on May 09, 2020, 02:58:05 PM
Thanks

Will take it out for a decent run with lights/screen on
Title: Re: Flat battery
Post by: guest9236 on May 09, 2020, 03:19:37 PM
Cigarette lighter socket is controlled by the ignition switch. As long as the ignition is turned off completely (0 position) before the key is removed (some posters have found they can remove the key in the Aux I position), then the cigarette lighter/power socket in not live.
The best way to charge the battery with the Jazz's charging system is to drive with the lights and possibly the rear screen on. At tick-over or low revs, there is hardly any charging happening.

Hi Jocko can you please explain for me ref Headlights etc on to increase charge rate,I have today taken the jalopy for a 40 mile run with only AC on have I wasted my time.
Thanks
Title: Re: Flat battery
Post by: Jocko on May 09, 2020, 03:45:53 PM
Most modern cars have a charging system which puts more volts out as the load is increased. With little load, the alternator will trickle charge the battery, fine when the battery is fully charged but not really enough when it is flat. As you increase the load the alternator puts out more, as you would expect, and the increased output makes for better charging.
Title: Re: Flat battery
Post by: culzean on May 09, 2020, 10:06:36 PM
Hi,

Battery is only about 6 months old


Despite the fact battery is only 6 months old you may have a dodgy battery, just like anything else they can be faulty from new.   If the alternator is capable of kicking out 14.2 + volts there is not much wrong with it.  In the past I have seen an alternators that have 'lost a diode' in the diode pack and could not reach 14 volts ( something around 13.7 to 13.8 which will not charge a battery ).

I have never heard of a battery discharging back through alternator.  If alternator is kicking out over 14.2 volts it should keep battery charged easily,  but frequent starts and short journeys can run a battery down. You really need to get a voltmeter and check voltage at battery terminals with engine running - it should be around 14.2 to 14.5 volts, should let battery stand for an hour after engine has stopped ( to get rid of 'surface charge' which can artificially raise the terminal voltage ).

Alarms and other parasitic drains like the boot light or interior lights are most likely, a relay stuck in would drain the battery in a very short time, ( measured in hours not days ) relays are used to supply heavy loads - Aircon relay stuck would drain a full battery in about 10 hours, rear screen about 3 to 4 hours.  Interior or boot light drawing 5 watts ( about 0.5 amps ) would take about 60 hours to drain a full battery.
Title: Re: Flat battery
Post by: Jocko on May 09, 2020, 10:17:39 PM
The first page of text tells all you need to know regarding charging with a load.
https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1011&context=auto_pres (https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1011&context=auto_pres)
Title: Re: Flat battery
Post by: guest9236 on May 10, 2020, 10:43:20 AM
The first page of text tells all you need to know regarding charging with a load.
https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1011&context=auto_pres (https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1011&context=auto_pres)

Thanks Jocko having perused your above  link twice.
I understood your previous explanation more easily so many thanks again for the knowledge.
But I must say it does seem very involved, it makes me wonder how my 1948 Austin 12 with its dynamo managed,as If I recall correctly it very rarely let us down.
Title: Re: Flat battery
Post by: Jocko on May 10, 2020, 10:56:13 AM
Yes, it comes down to shaving decimal places from emission figures.

(https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcTTviKEpZ9gytKYHYJfxLvtCmq0-Aqlullk7iWRihopItBF1MVT&usqp=CAU)

Not a lot to go wrong back then. Dynamo put out as much as it could with no concern over what it did for fuel consumption or emissions.
First of the alternator equipped vehicles were even better.
Title: Re: Flat battery
Post by: Darryl on May 10, 2020, 07:48:13 PM







I have never heard of a battery discharging back through alternator.  If alternator is kicking out over 14.2 volts it should keep battery charged easily, 

Sorry Culzean but it can definitely drain back through the alternator if the Diode is faulty.

It should only allow current to flow one way ie charging but if defective it will allow it to flow in either direction and yet still be capable of producing a charge rate of 14.2 when running

https://www.youtube.com/watch?v=oUhgyqm0wro (https://www.youtube.com/watch?v=oUhgyqm0wro)

Title: Re: Flat battery
Post by: Jocko on May 11, 2020, 11:11:01 AM
I went to the shops this morning after the car sitting in the garage since last Wednesday. Battery seems lively. I set my ScanGauge E to monitor the battery voltage, and it sat at 14.6 volts with and without the rear screen heater switched on.
Title: Re: Flat battery
Post by: John A on May 11, 2020, 11:42:22 AM
I went to the shops this morning after the car sitting in the garage since last Wednesday. Battery seems lively. I set my ScanGauge E to monitor the battery voltage, and it sat at 14.6 volts with and without the rear screen heater switched on.

I have a simple voltemeter in my 12v power source on my 2015 CVT Jazz and on the short journeys I'm doing it's conssitently showing 14.5v with or without the heated rear screen / lights / air-con being on.

Something like this:

https://www.ebay.co.uk/itm/Dual-Double-Car-Charger-Quick-Charge-Fast-12-24V-4-8A-2-x-USB-LED-Display-UK/273670682262?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 or

https://www.ebay.co.uk/itm/USB-LED-Car-Charger-Cigarette-Lighter-Socket-Power-Digital-Voltmeter-Thermometer/133395772738?epid=2175513440&hash=item1f0f01f542:g:S14AAOSwHk9epV75
Title: Re: Flat battery
Post by: Jocko on May 14, 2020, 11:43:53 AM
Had a 15-mile trip today and monitored the battery voltage. On startup it indicated 14.6 volts then after a couple of miles, it setted back to 12.7 volts. Then every two or three minutes it would cycle back to 14.6 before returning to 12.7 volts a minute later. One time it dropped back to 12.7 volts, so I switched on the rear screen heater, and it immediately increased to 14.6 volts. As soon as I switched the heater off, it returned to 12.7 volts. This voltage cycling indicates to me the ECU seeing the increased load and adjusting the charging rate accordingly.
Title: Re: Flat battery
Post by: culzean on May 14, 2020, 12:05:53 PM
Had a 15-mile trip today and monitored the battery voltage. On startup it indicated 14.6 volts then after a couple of miles, it setted back to 12.7 volts. Then every two or three minutes it would cycle back to 14.6 before returning to 12.7 volts a minute later. One time it dropped back to 12.7 volts, so I switched on the rear screen heater, and it immediately increased to 14.6 volts. As soon as I switched the heater off, it returned to 12.7 volts. This voltage cycling indicates to me the ECU seeing the increased load and adjusting the charging rate accordingly.

Good job,  that is what you would expect the electrical load detector ( ELD ) to be there for,  it is proper counter-intuitive to have to increase the load by turning equipment on to increase the battery charging though..  I watched the 4  LED lamps on my cigarette lighter expansion sockets and noticed the top two would go off for a while and then come back on - showing that alternator voltage was changing.

I was shocked when I fitted a new almost fully charged Li-Ion battery to my Phillips shaver ( soldered in ) and the shaver only lasted a few shaves before red lights flashed and it stopped - charging it had no effect -  I checked battery voltage and it was fine - but the shaver said NO !  I had to unsolder one end of battery and connect a 5 watt light bulb across it and monitor the voltage until it dropper to 'minimum voltage'  - then connected battery back and charged it - it has been fine ever since - the shaver was using 'coulomb counting' to check what was going in and out of battery and because battery was charged when I fitted it and the circuit saw nothing going in it stopped shaver even though battery was full.

looks like same coulomb counting system on the 'stop-start' jazz battery - which is why negative charger clip needs to go on an earth point and not battery terminal because clipping to terminal bypasses the charging sensor..
Title: Re: Flat battery
Post by: madasafish on May 14, 2020, 12:47:28 PM
The battery in my Jazz is now just over 8 years old.

I have been pushing the car out of the garage (downhill) daily to work in it making bits for beekeeping. And driving it back in again - uphill - when finshed.

After three days teh battery complained. Starter turnover was poor.

Charged it and tested battery voltage: 12.1V. Marginal.

As winter is coming .. and the demand for new batteries will surely increase as lockdown ends - I ordered a new Yuasa one from the links posted before..
Many thanks...
Title: Re: Flat battery
Post by: Jocko on May 14, 2020, 01:59:01 PM
Yes, as I said on another post today, 40% of the AA's call outs, yesterday, was for flat batteries.
Title: Re: Flat battery
Post by: culzean on June 10, 2020, 12:06:41 PM
Here is a reasonably priced double USB charger with voltage and current readout ( reads voltage when no USB device plugged in and display flips between USB charging current and system voltage when something plugged in ).

https://www.amazon.co.uk/Dual-USB-Car-Charger-Built/dp/B01N5I0J92/ref=pd_rhf_ee_s_bmx_0_10?_encoding=UTF8&pd_rd_i=B01N5I0J92&pd_rd_r=d1bc9f54-2af8-4e19-adb2-5b6ea52b68b0&pd_rd_w=qfs4V&pd_rd_wg=mEhoL&pf_rd_p=4416d6a2-fd8f-40d0-816e-4414687de4d4&pf_rd_r=X467XRQQXD87571DVT92&psc=1&refRID=X467XRQQXD87571DVT92