Solar trickle charger through power socket

[The_ASH]

I've used several different small solar panel chargers to keep my Golf alive during long periods of inactivity (3/4 weeks). It seems on that car the voltage regulator remains active all the time as long as whatever input voltage is connected to the battery positive and chassis negative (not direct to battery negative), presumably this is mainly to protect the electronics in the car from exposure to voltages above a certain amount, it does seem to protect the battery from being boiled dry but then it is a maintenance free item and I'm not charging it for long periods.

I guess as the electrical system on a K Seven is older the voltage regulator built into the alternator only operates when the ignition is on, can anyone confirm this?

[pugwash]

I have a 2012 super sport with a 140 sigma and the FIA master cut off switch, factory fitted.  On mine when you flick the switch the immobilized light goes out so I guess everything is powered down.  

Having read the thread again, I am wondering why you don't just fit a simple switch, discarnect style, to the battery and then just switch it off when not using it.   I realize you would need to lift the bonnet to do this but it's only 4 catches and when turning it off you would not do the catches back up until you turn it on again.  As back up, a battery on the ground with a set of jump leads seems simplest solution.  Or even one of those new lithium jump packs which I have seen but confess have no direct experience of.

[Jonathan Kay]

It seems on that car the voltage regulator remains active all the time as long as whatever input voltage is connected to the battery positive and chassis negative (not direct to battery negative)...

What have you observed that suggests that?

Or even one of those new lithium jump packs which I have seen but confess have no direct experience of.

Yes, that's why I was interested in the likely cost.

Jonathan

[AdrianC]

 I just fitted one of these

https://www.amazon.co.uk/d/k5c/Car-Battery-Isolator-Cut-Off-Switch-500A/B003DYQYXC

through the passenger bulkhead in the footwell and connected it across the negative

15min job to install and cuts all current drain

[anthonym]

I used one of those small lithium battery jump start things to start a dead Porsche in the entrance queue at Schloss Dyke couple of weeks ago, successfully to the surprise of everyone present including me. 

They work, though how often without recharge I don't know. Having read all this thread from the op, I used to use solar panels (plural because two cars) as a trickle (so unregulated) maintenance charge until they were stolen (no theft in Switzerland eh?). I had the cut-out key removed.  These days I just pull the cut-out and jump if required at the beginning of Spring. We get more sun here.

All sounds a bit complicated versus pulling the cut-out key and having a booster, that one should have anyway. Always nice when she starts after the whole Winter "sleeping".

Anthony

[twincamtim]

I have one of those lithium jump packs, ~£30 from eBay. It works fine and I have had at least 3 or 4 starts out of one charge. I have never used it so much in one go it doesn't work (aren't lithium batteries funny about being run flat?) so I can't say how many starts you'd get before it was flat.

I have just had a cut-off switch fitted to avoid the constant drain caused by the alarm so I don't expect to have to use it much anymore but I'll always carry it as a back-up. Mine has a good LED torch in it and USB socket for running a sat-nav or charging your phone!

[The_ASH]

I initially observed the VW marking under the bonnet that says to only connect to battery positive and chassis earth (which is not connected direct to battery negative), if I connect the Optimate to the car a small fight eventually breaks out between the chargers programming and the cars max volts limit (full charge is achieved however) with other non-intelligent chargers and especially solar chargers which in some cases attempt to raise the dc to 20 something volts, with a volt meter it can be observed that the battery voltage never crosses 14v. Something in the background is acting like a solar charge regulator.

[Jonathan Kay]

Thanks

No, I haven't seen anything like that reported on any 7.

Jonathan

[Jonathan Kay]

Lithium battery jump packs, from the archives (but the search gets confused with lithium main batteries).

Jonathan

[L777JDP]

Hello everyone,

I've had confirmation from Caterham that they can fit a battery cut off switch and leave the 12V power socket connected across the battery with the switch turned off. They are just 20 mins down the road from me, so a resource I can easily make use of as I'm in Horsham.

That should be enough, but I'll get a small solar panel at around 20W, that just has bear wires so I can connect it to a separate battery conditioner. This looks pretty good for the panel: https://www.amazon.co.uk/gp/product/B008BUZNLW/ref=ox_sc_sfl_title_2?ie=UTF8&psc=1&smid=A2PPJZ27RJ59I5 and this for the battery conditioner: https://www.amazon.co.uk/gp/product/B06XMYQB8S/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=A2JZY3640F5Q45 which will show the state of the battery, so I can monitor how it goes over the winter.

The weather is often very mild here in the south, so often the roads don't get gritted until January/February time, so there should be plenty of crisp sunny days in late autumn/early winter when I can just switch the battery back on, knowing (or at least expecting) it to fire up OK.

John.

[Jonathan Kay]

... so I can monitor how it goes over the winter.

Looking forward to the data.

... and leave the 12V power socket connected across the battery with the switch turned off.

If you have to change or work on the socket etc I'd consider fitting one with both cigar lighter and USB sockets.

Jonathan

... that just has bear wires...

Might be a bit sluggish in the winter ;-)

[The_ASH]

I used that exact charge controller on my now disassembled solar charging setup. Basically 30w's worth of solar and a 70ah leisure battery, later it morphed into 45w's of solar. It all worked ok but as with many things the more you pay the better you get. The setup you describe should be more than enough to keep a Banner battery on a Seven alive even in Winter, the main and most important thing to remember is to regularly check the electrolyte levels, my main memory of my setup was that when charging the quickest way to check if it was all functioning was to to listen to the battery fizzing away, the sunnier it was the more ferocious the fizzing!

MPPT controllers are more efficient than the PWM type, the controller you've listed used to be listed as MPPT on eBay... it isn't it's a PWM and is the same as another controller that can be found for 99p on the auction site, I think I payed £6 for mine.

Anyway, keep checking the electrolyte and that on really sunny days that the battery isn't getting warm by 3pm'ish and all should be fine.

[Blue C7]

Just to add my own experience. I fitted a battery isolation switch accessible in passenger foot well and a powervamp battery four years ago. Car on axle stands for six months over winter. Plugs out, turn over engine for oil pressure. Plugs in car started first push of button. I set immobiliser before turning off battery