Author Topic: Battery Trickle Charging  (Read 5937 times)

Traveller

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Battery Trickle Charging
« on: December 22, 2017, 07:51:32 PM »
My Jazz is sometimes left unused for quite long periods, so I need to leave the battery on trickle charge. My problem is finding a sensible and convenient way to connect the trickle charger to the battery when the car is standing in the garage. I do not want to lift the bonnet and fiddle about with croc clips every time I park the car, and repeat when I want to drive off.

With previous cars I have solved the problem by feeding the trickle charger output through the cigar lighter or the relevant terminals of the OBD2 connector. This is convenient because the cable from the charger (suspended in the garage roof) falls close to the driver's window - just open the window and plug in before getting out of the car., and vic versa.

Both these methods have worked well in the past with various cars. However, the Jazz seems to disconnect power to the cigar lighter and the OBD2 connector when the ignition is turned off. This is a relativel common problem with modern cars featuring high parasitic battery drain, but manuafacturers never seem to offer a practical solution.

Does anyone have a nice neat method that does not involve hacking into wiring looms etc?

culzean

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Re: Battery Trickle Charging
« Reply #1 on: December 22, 2017, 08:49:17 PM »
https://www.amazon.co.uk/dp/B01M03OM9D/ref=cm_cr_ryp_prd_ttl_sol_10

https://www.amazon.co.uk/dp/B009YJ0QF2/ref=cm_cr_ryp_prd_ttl_sol_12

See attached PDF with photo,

I use this connector on my motorbikes and two cars (Jazz and Civic) - the extension lead means charger can stay in garage if car is outside (which our cars are).   The permanent lead comes with a inbuilt standard car type blade fuse in positive side and lugs with 6mm hole in that fits over existing 6mm bolts that hold terminal clamps onto battery.  The red cover flips off plug to allow it to be plugged in,  but will keep out damp and dirt (these are designed for motorbikes and quad bikes so it is really a cover to keep water out when not in use). There are shorter extension leads available but not really that much cheaper so may as well buy the longer one to give you option of having car further from charger if needed.

You can either get an optimate or any similar battery charger which will already have SAE plug fitted or cut one end off the extension lead and bare the ends to attach to your existing charger crocodile clips (which is what I have done for my Halfords charger) - make sure you get polarity correct though or something will go bang. 

I just lay cable across front of bonnet opening and close bonnet after it is plugged in (there are rubber stops on bonnets so there is a gap for cable even when bonnet is closed) main thing you have to do is remember to unplug before you drive off --------------- :-X  :-X



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« Last Edit: December 22, 2017, 09:01:41 PM by culzean »
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Traveller

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Re: Battery Trickle Charging
« Reply #2 on: December 22, 2017, 09:04:28 PM »
Thanks for your reply. What you describe is about as far as I have got. Maybe I am lazy, but I would really like some form of in-car solution so that it is not necessary to open and close the bonnet twice for each use of the charger.

guest1372

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Re: Battery Trickle Charging
« Reply #3 on: December 22, 2017, 09:11:32 PM »
Interesting point, and one which works the other way as well (leaving OBDII code reader plugged in to Jazz GD/GE is OK but may drain other cars).

There is permanent power available behind the dash for lights and trickle power for things like the radio, remote locking etc.  Gaining access to these wires might be more work than you are prepared to do, but the fuses should be an easier way of getting a connection. 

On Mk2/GE models so many sub-systems are not wired directly through switches but via the multiplex control unit, one of the few that is a simple open/close circuit is the brake lights.  It may be possible to back feed the battery circuit by connecting to the brake light fuse in the under dash fusebox by using a fusetap.  Many of the fuses in this box are ignition switched, but #24 (10A) for the brake lights is one of the permanent ones.  The fuse is upstream of the brake pedal switch so there should be no danger of powering the lights unintentionally by the charger. 

There may well be other or empty fuse bays that are also permanently powered, but that would require a bit of trial and error with a multimeter.

I have a solar trickle charger that came with a fairly easy polarised inline connector to enable easy hookup to a more permanent lead tucked away somewhere, something similar should prevent accidental reverse polarity incidents.
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Jocko

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Re: Battery Trickle Charging
« Reply #4 on: December 22, 2017, 10:16:56 PM »
Traveller, what model/year is your Jazz?

culzean

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Re: Battery Trickle Charging
« Reply #5 on: December 23, 2017, 09:23:58 AM »
Maybe I am lazy  :-X, but I would really like some form of in-car solution so that it is not necessary to open and close the bonnet twice for each use of the charger  :'(

If car is in garage you could leave bonnet propped fully open when charging anyway, will remind you not to drive off before disconnecting as well.  When you said the battery needs to be trickle charged 'sometimes' I imagined a few times a year, in which case it would not be too troublesome to open and close bonnet.

The system works for me because on motorbikes you have to take saddle off to access battery terminals,  with the charging lead the plug just pokes out under saddle and  cap is on all the time it is not charging, so it's waterproof.   It also means there is one standard polarised plug for everything (although my charger like a lot of modern chargers won't output any power until leads are connected to a battery (ant-spark) and in the correct polarity (won't try to reverse charge the battery),  but it does mean it won't even try to charge a battery where voltage is too low - if you need to charge a flattened battery you need to hook another battery in parallel to fool the charger and charge both until the 'bad' battery gets enough juice to fool the charger on its own.

You could get a Yuasa 'Silver' battery (same as the one in my photo) which have really really low level of self discharge,  I have left my car standing for over 3 weeks, hooked up my charger and within 5 minutes the green light on charger has come on to indicate 'battery is fine, now switching to low trickle charge'. Normal lead acid batteries suffer from stratification and surface charge + sulphation if left undercharged - AGM batteries are pretty immune to all those  http://batteryuniversity.com/learn/article/water_loss_acid_stratification_and_surface_charge

This is convenient because the cable from the charger (suspended in the garage roof) falls close to the driver's window - just open the window and plug in before getting out of the car., and vic versa.

I read on a lot of motorbike forums that people remove their saddles during winter when bike is laid up,  apparently mice just love to chew up and make nests in the foam - don't leave your window open  more than a few mm because apparently mice can squeeze through a hole that is only same diameter as a pencil.   https://www.irishtimes.com/news/environment/rodent-season-if-you-can-poke-a-biro-through-a-hole-a-mouse-can-get-in-1.1604451
« Last Edit: December 24, 2017, 10:52:09 AM by culzean »
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John A

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Re: Battery Trickle Charging
« Reply #6 on: December 23, 2017, 09:41:56 AM »
Thanks for your reply. What you describe is about as far as I have got. Maybe I am lazy, but I would really like some form of in-car solution so that it is not necessary to open and close the bonnet twice for each use of the charger.

Then why not have a cigarette lighter which is in the passenger compartment and which is  wired direct to the battery, and have the trickle charger with an end like this

https://www.infinitymotorcycles.com/product/optimate-m79-o02-bike-cigarette-lighter-sae?gclid=CjwKCAiAmvjRBRBlEiwAWFc1mJplofx2BvtxS-M70X0PdiT12YHA77f1OIdRbvE0W1cu0qF5tWvlaxoCmLUQAvD_BwE

Traveller

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Re: Battery Trickle Charging
« Reply #7 on: December 23, 2017, 10:22:29 AM »
Thanks for all the comments - they are appreciated.

The car is  a late 2013 1.4 i-VTEC ES Plus 5dr CVT.

I do need to trickle charge the battery most of the time because I rarely know, when I park it in the garage, how long it will be before it gets further use. Sometimes I use it again the following day but on other occasions it may sit unused for a week.

The cigar lighter approach seems to be the best one, but that means bypassing the ignition switch by taking a convenient battery live directly to the cigar lighter. Is anyone aware of the easiest way to do that?

guest1372

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Re: Battery Trickle Charging
« Reply #8 on: December 23, 2017, 01:48:06 PM »
The cigar lighter approach seems to be the best one, but that means bypassing the ignition switch by taking a convenient battery live directly to the cigar lighter. Is anyone aware of the easiest way to do that?
The simplest way may be to adapt the power feed to the existing accessory socket.

With a fuse tap again you could take one of the permanent power feeds such as the brake lights and jumper that across to the accessory socket fuse #13 with it's own fuse removed and placed in the fuse tap.  It will be critical to connect to the downstream end of the accessory socket fuse bay.  A non permanent, easily reversible solution.

This is what Skoda owners do to change their permanent powered accessory sockets to ignition switched when powering dashcams.

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Traveller

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Re: Battery Trickle Charging
« Reply #9 on: December 23, 2017, 03:03:44 PM »
Thank you - that sounds like a brilliant idea. I will try i as soon as I have the necessary bits and pieces.

Jocko

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Re: Battery Trickle Charging
« Reply #10 on: December 23, 2017, 05:44:41 PM »
To be absolutely honest, if you cannot leave your car for a week and have the battery reliably hold its charge, I think a new battery is called for, not a trickle charger. My car starts reliably after 6 weeks untouched.

culzean

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Re: Battery Trickle Charging
« Reply #11 on: December 23, 2017, 07:15:18 PM »
To be absolutely honest, if you cannot leave your car for a week and have the battery reliably hold its charge, I think a new battery is called for, not a trickle charger. My car starts reliably after 6 weeks untouched.

+1

Exactly what I was thinking ( I suggested the Yuasa Silver battery),  I thought 'Traveller' car was being lefts for months at a time - all I would do is take it for a decent run before leaving it.
« Last Edit: December 24, 2017, 10:51:18 AM by culzean »
Some people will only consider you an expert if they agree with your point of view or advice,  when you give them advice they don't like they consider you an idiot

Traveller

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Re: Battery Trickle Charging
« Reply #12 on: December 24, 2017, 10:32:23 AM »
Thanks for all the replies - very useful.

It is of course correct that the battery should easily withstand one week without use. However, as I probably should have explained, this pattern of infrequent use sometimes goes on for extended periods. Yes, the battery is OK after one week of standing, and two and three etc, but the use of the car in between is apparently insufficient to replace the charge used by the starter motor and through parasitic drain. The result is that, eventually, the car will not start. The problem is essentially a cumulative one arising from low levels of use. I drive around 4,000 miles per year - mostly on country roads.

I have experienced the same problem with previous cars, even replacing the battery only to find the same difficulty returning after a few months. I have previously completely solved the problem by leaving the battery on trickle charge all the time - hence the desire to find a very convenient solution for attaching the leads.

Five years ago I took my previous car for its MOT, and was told that the battery was "unserviceable". I did not believe this because it was a good quality battery for which I had paid a premium price, and it was only two years old! That was when I decided to use a trickle charger all the time. The same "unserviceable" battery was still serving perfectly four years later when I disposed of the car.

I am grateful for all the comments. Thanks and best wishes.

culzean

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Re: Battery Trickle Charging
« Reply #13 on: December 24, 2017, 10:55:47 AM »
Lead acid batteries need to be kept withing the top 20% state of charge to ensure longest life (this is different to Lithium Ion, which do not like being kept fully charged),  and every time a battery is allowed to go below about 50% for any length of time it suffers damage,  if allowed to go completely flat it may never recover.  IMHO parasitic losses on Jazz are very low unless you have an alarm fitted - alarms are notorious for draining the battery just with their standby power requirements. 
Some people will only consider you an expert if they agree with your point of view or advice,  when you give them advice they don't like they consider you an idiot

Traveller

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Re: Battery Trickle Charging
« Reply #14 on: January 09, 2018, 07:33:46 PM »
I have finally resolved this matter by setting up a trickle charger and feeding the output to pins 16 and 4 of the OBD-2 connector which I discovered is not disconnected when the ignition is switched off. I used a cigar lighter type plug and socket (Ebay), with the plug wired to the (switched) charger output and the socket permanently wired to an OBD-2 plug (the latter being left plugged in to the OBD-2 socket under the dashboard).

 I do not know whether the pinout on OBD-2 connectors is always the same but I'm sure there is an agreed standard. I believe it is correct that an OBD-2 connector must have pins 4, 5 for ground connections and pin 16 for 12 volt power supply direct from the vehicle battery. Therefore if only pins 4 and 16 are used, it is quite safe to connect the output from a trickle charger to the battery via this route. I checked my reasoning with a garage technician and he agreed it was an OK soultion. Note that the current rating of the wiring to the OBD-2 connector is not adequate to carry the current from a normal battery charger - only a trickle charger!!

I hope this may be of use to other people, but do not attempt to do it without first checking the wiring on the particular vehicle, and the current output from the particular trickle charger.

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