Connecting solar panel to a battery on a Defender Puma

Hi All,
I am unable to drive for a few months. Vehicle is a 2008 Puma Defender with original battery which is in good condition. I understand the battery will drain if not used. I have a 20 watt solar panel with charge controller and wonder if I can connect this directly to the battery while leaving the battery fully installed in the vehicle. Thanks Mike.

I can't see why not unless you have a drain greater than the charge from the solar panel. Don't leave it in your windscreen as solar panels need the uv to charge and the screen protects from uv. You'll have to leave it outside with cables running inside

Find what the quiescent battery drain is, then adjust the solar charge controller to match that. Depending where you are in the world of course but in the U.K in winter I doubt a 1.6amp solar panel would be sufficient to keep a vehicle battery topped up for months your unable to drive it.
I have a car in a garage connected to a Ctec battery charger for most of the year which is the smarter way to charge a vehicle battery.

The only things that can reduce batteries are alarms fitted clocks ecu etc. You could rig up a trickle charger and have an outside weather proof wall socket to feed the unit. Solar Panels work better outside the car but you fall prey to the alarm sensors detecting a window open when locked up. Are you able to feed the solar panel cables into a grommet of the battery bay under the seat then take the panel an place on the roof.

Solar panels don't rely on uv but its best on the outside of the car.
And don't forget it's winter now so your not going to get too much juice out of it, get one of the plug in the wall battery monitors, much safer if you ask me.

pete1987RRC said:

Solar panels don't rely on uv but its best on the outside of the car.
And don't forget it's winter now so your not going to get too much juice out of it, get one of the plug in the wall battery monitors, much safer if you ask me.

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Thanks for replies. Vehicle does live outside. I do have a 240v 10 amp charger of a suitable type for the battery. My choices are to:
1. Use the solar panel as above.
2. Remove the battery from the vehicle and charge indoors.
3. Leave the battery connected to the vehicle and use a short extension lead to facilitate charging with the 240v charger .
Am I correct in thinking removing and refitting a battery from the vehicle can create problems?

Thanks. Mike

2 months is not that long - maybe charge it twice over that period from a mains charger, and leave it at that.

think about how long a bedroom alarm clock runs for on a couple of AA sized batteries - your car clock is not going to drain a 80ah battery that quickly

mike56 said:

Hi All,
I am unable to drive for a few months. Vehicle is a 2008 Puma Defender with original battery which is in good condition. I understand the battery will drain if not used. I have a 20 watt solar panel with charge controller and wonder if I can connect this directly to the battery while leaving the battery fully installed in the vehicle. Thanks Mike.

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In theory yes it will be fine. In practice you will find that the panel will not be as efficient as it claims and most of the time the vehicles current draw and the batteries self-discharge rate will exceed the solar panels output - having said that better than nothing. In the summer my friend does this to keep his tractor battery topped up and to be honest it does work, but then the tractor has no parasitic draw.

Personally I would go for the C-Tek or Ring etc. (same charger cheaper price) microprocessor controlled charger and hook it up for a trickle charge option. If you cannot leave it setup outside or in a garage then yes bring the battery inside. Even just having it inside will help it last as it won't get as cold. Are you going to be about? If yes take it out the LR, give it a full charge then leave it for a month, put it back on the charger after a month should work fine.

I use solar chargers to keep the batteries topped up in both my cars. As said above, there's not much charge in the winter, but it will definitely help. Inside the vehicle, it may only be producing 5 watts during the day, but that should be more than enough to cope with the radio and alarm demands.

Or you could lend me your 90 whilst you cannot drive. I'll be sure to keep the battery topped up

Are there issues with the trickle charges and alternators??

Usually you would not charge when on the car as it screws the alternator over, of courses you can disconnect the4e red lead.


Solar panels only give max output when the sun shining bright and strong (mid summer) and is 90deg to the panel, all other times its lower, often much lower which is why on your house roof panels performance is naff if you live north of london with an average angle pitch roof.

If you're going to use a trickle charger then take the battery off the vehicle to do it. It will make the vehicle harder to steal

pete1987RRC said:

Are there issues with the trickle charges and alternators??

Usually you would not charge when on the car as it screws the alternator over, of courses you can disconnect the4e red lead.


Solar panels only give max output when the sun shining bright and strong (mid summer) and is 90deg to the panel, all other times its lower, often much lower which is why on your house roof panels performance is naff if you live north of london with an average angle pitch roof.

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Ive got three cars and I use a trickle charger on and dont disconnect anything, all cars have a dash mounted voltmeter and all charge just lovely.
At work Ive never disconnected the alt/batteries when charging/boosting or even welding.

mike56 said:

Am I correct in thinking removing and refitting a battery from the vehicle can create problems?

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Yes, there is a procedure in the workshop manual for disconnecting the battery (which I will check later) - but from memory you need to slacken the live lead battery connector but do not remove it, turn on the ignition so all the dash lights come on (but don't turn the engine over), turn ignition off and within 15 seconds pull the live lead off the battery. Think it is something to do with storing information in the ECU. I will consult the manual and post again later to confirm.

Update
Battery disconnection is detailed in the owners handbook. Disconnection is required within 15 seconds of turning the ignition key off if there is a anti theft siren fitted, this procedure stops the siren sounding. Undo the negative (black) lead first (not the live like wot I said earlier).
When refitting the battery you will need to reset the radio security code and re-synchronise the key fob. The rest of the vehicle systems reset automatically, some need the vehicle to be driven for a few minutes.

I bought one of these a couple of years ago and leave it plugged into the fag lighter when it's parked up for long periods - never let me down even on the coldest/wettest weeks....the panel is zip tied to the sun visor.

https://www.ebay.co.uk/itm/290369389085

thats ok if the fag Lighter is perm live, most arnt

pete1987RRC said:

thats ok if the fag Lighter is perm live, most arnt

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That would be well chuckle worthy if his fag lighter is in fact ign live

Every Landrover I've owned has had a live fag lighter with Ign. off - but I've never owned a Puma, so I bow to your superior knowledge......

Thanks again for replies.

I have found the section in owners manual ref batteery. Thanks. The reason I am off the road is due to cataracts and I might well have looked in the manual before posting but great difficulty reading. and typing Got my wife to read it. I have connected the solar panel now. However I considered the problem of creating problems in the ecu etc by disconnecting the battery and concluded the solution is to connect a spare 12v battery to the terminals or other suitable place prior to disconnecting original battery and removing for charging. This could be achieved with jump leads or a couple of leads with crocodile clips. the only issue is ensuring continuous 12v to the vehicle. Just ensure one of the terminals is not accidentally knocked off!

Mike