Fitting halfords solar panel to 203 coupe

andrew Slater

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Hi all,
Not using the car during lockdown, my battery completely died. I now have a nice shiny new battery. So, I thought if I fit a solar battery maintainer, I won't suffer the whole process again.
My question is :-
I plan to fit on my parcel shelf. Connect to the constant 12v positive on rear Sam, but want to put an inline switch on the positive side so I can disconnect it for driving and turn it back on again when parked.
I plan to run the positive under the carpet and bring it up to the centre console for the switch. (A) would this work?
(B) how much of a ball ache would it be to feed the cable under the carpet to the centre console?
I thank you all in advance, for any, advise, instruction or warnings on the subject.
Regards to all
 

Kev555

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If your not using the car I would leave the battery on a bench rather than have it sitting in car draining away. Some of the other guys on the forum here with experience in long term storage of vehicles have recommended this https://www.ebay.co.uk/itm/MAYPOLE-...331302&hash=item4d6dab740b:g:DyEAAOSwWktagYa~ If you can safely run an electrical lead to the car.
I haven't used a solar charger so I cant recommend them
 

AnthonyUK

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How ‘smart’ are those solar chargers?
I use a CTEK which has been tried and tested over many years and is what I would recommend. My battery is more than 15 years old so I know it works for me.
 

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I have Optimates or Cteks on the vehicle’s I’m not using. My SLK is used every week or so and no issues with leaving it without any battery charger.
My smart isn’t in a location where it can be connected to the mains. I fitted a solar charger direct to the battery under the passenger footwell. Fused the supply but no switch as the pull apart connection is in the footwell and it’s disconnected every time it’s used.
The battery was starting to show its age until I fitted the solar charger. It doesn’t have much output but it’s saved the battery in the smart.
 

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Fortunately our 2 cars & motorbike are in the garage. My bike is on a Optimate, & I use a standard 5 amp charger alternative weeks on both cars. I leave it on charge for about 5/8 hours, until the charge is under 1 amp.The first cars battery is 9 years old, the second I changed last year at 9 years old. The bike battery is 5 years old.
 

Kev555

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How ‘smart’ are those solar chargers?
I use a CTEK which has been tried and tested over many years and is what I would recommend. My battery is more than 15 years old so I know it works for me.

I would swear by Ctek too as regards keeping a battery in tip top shape Anthony. I did find if a battery is very low the Ctek mx5 can show up an error as if the battery is faulty, but i find if I put the battery on my old charger on trickle charge for 24hrs the Ctek can take over from there and leave battery back to full health
 

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I think Andrew wants to fit this type of solar charger to his car, and not charge the battery in the normal way. Maybe the thought of power cables sitting across the drive way is not an option . I think its a good idea to have a solar charger to keep battery topped up . But need to go right on to the battery posts .
 

Tony Dyson

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Hi all,
Not using the car during lockdown, my battery completely died. I now have a nice shiny new battery. So, I thought if I fit a solar battery maintainer, I won't suffer the whole process again.
My question is :-
I plan to fit on my parcel shelf. Connect to the constant 12v positive on rear Sam, but want to put an inline switch on the positive side so I can disconnect it for driving and turn it back on again when parked.
I plan to run the positive under the carpet and bring it up to the centre console for the switch. (A) would this work?
(B) how much of a ball ache would it be to feed the cable under the carpet to the centre console?
I thank you all in advance, for any, advise, instruction or warnings on the subject.
Regards to all

In response to your original query;

A, Yes but there is a better way, the way you have described would mean a total of around 4m of cable run from rear to front then back to rear, then to the battery on existing wiring! which would be subject to unnecessary volt drop, I would run the +ve from your PV panel, via an inline fuse to the live input on your rear SAM, then run the -ve from the PV panel under the carpet to your choice of location for the sw, terminate to one of the sw contacts and then terminate the second contact of your switch to a -ve ground point under the centre console, ensuring the cable chosen to lengthen the -ve lead from your PV panel is greater in CSA than existing thereby mitigating an potential excessive volt drop by adding to the total length of run of any additional wiring. I'm not going to bore you with Volt Drop calculations but as you're only starting off with an output voltage of just north of 12v and you're looking to charge a 12v battery at the front of your car, there is not a lot of leeway before volt drop would effect the successful operation of the PV charger.
 
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andrew Slater

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Thank you all for your replies. I am now feeling a little bewildered. The battery is brand new now. I have the solar panel, which I intend to fix permanently on the parcel shelf in the back. From there, I thought it would be a good idea to put a breaker switch on the positive side, to disable the panel prior to starting the car and driving, and turn it back on when parked outside. Thus, maintaining my battery. I assumed that I could connect the panel via the switch to the constant positive on the rear Sam unit and ground to the rear ground point. ( I mentioned this to the halfords guy who fitted the NEW battery, and he seemed to think it would work), as it is only a trickle charge the 2.4w output solar panel gives.
Can anyone please confirm, that in fitting it this way, that it would work?
Thanks to all.
 
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andrew Slater

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In response to your original query;

A, Yes but there is a better way, the way you have described would mean a total of around 4m of cable run from rear to front then back to rear, then to the battery on existing wiring! which would be subject to unnecessary volt drop, I would run the +ve from your PV panel, via an inline fuse to the live input on your rear SAM, then run the -ve from the PV panel under the carpet to your choice of location for the sw, terminate to one of the sw contacts and then terminate the second contact of your switch to a -ve ground point under the centre console, ensuring the cable chosen to lengthen the -ve lead from your PV panel is greater in CSA than existing thereby mitigating an potential excessive volt drop by adding to the total length of run of any additional wiring. I'm not going to bore you with Volt Drop calculations but as you're only starting off with an output voltage of just north of 12v and you're looking to charge a 12v battery at the front of your car, there is not a lot of leeway before volt drop would effect the successful operation of the PV charger.
In response to your original query;

A, Yes but there is a better way, the way you have described would mean a total of around 4m of cable run from rear to front then back to rear, then to the battery on existing wiring! which would be subject to unnecessary volt drop, I would run the +ve from your PV panel, via an inline fuse to the live input on your rear SAM, then run the -ve from the PV panel under the carpet to your choice of location for the sw, terminate to one of the sw contacts and then terminate the second contact of your switch to a -ve ground point under the centre console, ensuring the cable chosen to lengthen the -ve lead from your PV panel is greater in CSA than existing thereby mitigating an potential excessive volt drop by adding to the total length of run of any additional wiring. I'm not going to bore you with Volt Drop calculations but as you're only starting off with an output voltage of just north of 12v and you're looking to charge a 12v battery at the front of your car, there is not a lot of leeway before volt drop would effect the successful operation of the PV charger.
Thanks Tony,
I had initially thought of that but questioned myself, in regards to the +ve being constant connect when starting.?, I wasn't sure if it would not affect the panel during starting engine.
 

Tony Dyson

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Thank you all for your replies. I am now feeling a little bewildered. The battery is brand new now. I have the solar panel, which I intend to fix permanently on the parcel shelf in the back. From there, I thought it would be a good idea to put a breaker switch on the positive side, to disable the panel prior to starting the car and driving, and turn it back on when parked outside. Thus, maintaining my battery. I assumed that I could connect the panel via the switch to the constant positive on the rear Sam unit and ground to the rear ground point. ( I mentioned this to the halfords guy who fitted the NEW battery, and he seemed to think it would work), as it is only a trickle charge the 2.4w output solar panel gives.
Can anyone please confirm, that in fitting it this way, that it would work?
Thanks to all.
Theoretically, Yes
Practically, it's doubtful due to the complications listed previously.

Thanks Tony,
I had initially thought of that but questioned myself, in regards to the +ve being constant connect when starting.?, I wasn't sure if it would not affect the panel during starting engine.

The PV panel would not normally be affected by the starting of your car, there are many, more sensitive pieces of kit car connected than a solar PV panel, your enemy in this instance is Volt Drop as you are fitting the panel around 2m length of run from where it would be optimum.
 
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andrew Slater

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Theoretically, Yes
Practically, it's doubtful due to the complications listed previously.



The PV panel would not normally be affected by the starting of your car, there are many, more sensitive pieces of kit car connected than a solar PV panel, your enemy in this instance is Volt Drop as you are fitting the panel around 2m length of run from where it would be optimum.
Thanks again Tony.,
Hmm, so, if there's minimal risk of damaging solar panel on starting, should I bother with a switch at all. Just make a permanent, (shorter cable length) fitting. And connect directly to the +ve on rear Sam, and - ve to ground point by rear light cluster?
 

Tony Dyson

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Thanks again Tony.,
Hmm, so, if there's minimal risk of damaging solar panel on starting, should I bother with a switch at all. Just make a permanent, (shorter cable length) fitting. And connect directly to the +ve on rear Sam, and - ve to ground point by rear light cluster?
I see no technical reason for the switch, I would assume, without access to the OM, the output voltage of the PV panel will be in the same region of the car's charging voltages say around 13-15vdc so without a sw the PV panel would simply be a constant power source regardless of the car's status and/or in my particular case, short term memory lapse :) your PV panel will be working 24/7 anyway so whatever you connect it to will not have any detrimental effect on it's expected lifetime, the shorter the cable run the better.
 
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andrew Slater

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I see no technical reason for the switch, I would assume, without access to the OM, the output voltage of the PV panel will be in the same region of the car's charging voltages say around 13-15vdc so without a sw the PV panel would simply be a constant power source regardless of the car's status and/or in my particular case, short term memory lapse :) your PV panel will be working 24/7 anyway so whatever you connect it to will not have any detrimental effect on it's expected lifetime, the shorter the cable run the better.
Thanks again,
It's a mid range panel.
IE, 12v, 2.4w panel with 138ma at max power output.
The cable length in the box is 2.7m, so I can drastically reduce that length by connecting direct to where I mentioned. Probably about a metre max!
Thank you so much for all your help and suggestions Tony.
Right, I'm off to fit a solar panel, yippee. Ooh I'm getting all excited, lol.
 

Tony Dyson

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Thanks again,
It's a mid range panel.
IE, 12v, 2.4w panel with 138ma at max power output.
The cable length in the box is 2.7m, so I can drastically reduce that length by connecting direct to where I mentioned. Probably about a metre max!
Thank you so much for all your help and suggestions Tony.
Right, I'm off to fit a solar panel, yippee. Ooh I'm getting all excited, lol.

The figures you have just provided indicate a charging voltage of 17.39v but with manufacturers optimism and undisclosed inefficiencies I would expect that figure to be closer to 15.5v so all's good and chopping off a metre
will help with the additional fixed wiring from the rear SAM to the battery, good luck and let us all know how it works out.
 
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andrew Slater

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The figures you have just provided indicate a charging voltage of 17.39v but with manufacturers optimism and undisclosed inefficiencies I would expect that figure to be closer to 15.5v so all's good and chopping off a metre
will help with the additional fixed wiring from the rear SAM to the battery, good luck and let us all know how it works out.
So sorry to bother you again but,
I've just put my multimeter on the panel and it's pumpin out 19.93V, isn't that a little high? I'm now a little concerned about fitting the darn thing
 
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andrew Slater

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Wow, the little solar panel is pushing 19.93v according to my multimeter, isn't that a tad too high. I don't want to fit it and create a whole new headache for myself.
Regards
 

Tony Dyson

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Manufacturers will often allow in their calculations for an expected level of volt drop and the overall impedance of a connected load, connect your panel to a battery (not connected to your car) and then measure the voltage again, what do you get this time? and have you already cut the leads from the panel or are they still intact?
 
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andrew Slater

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Manufacturers will often allow in their calculations for an expected level of volt drop and the overall impedance of a connected load, connect your panel to a battery (not connected to your car) and then measure the voltage again, what do you get this time? and have you already cut the leads from the panel or are they still intact?
Hi,
No I have not yet cut the leads I just thought I would do a quick reading before I started messing with it, so placed in direct sunlight with nothing connected to it I am now getting 20.6v at the ends of the panels leads. I'll try it again with it clamped to the battery and see what I get then.
 

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