WheelchairDriver

I have got the Dahl docking station installed in my Mercedes sprinter. There's always a red light illuminated on the button. Does that mean the whole system is alive all the time? Could this be draining my battery over a week?

Yes it needs a constant live, I don't know the current draw mind.

I was wondering whether it would be possible to plug a small solar panel into the cigarette lighter in order to keep the battery charged. I have a similar system on a leisure battery in my back garden that keeps a battery charged for the electric winches on my radio tower.

I went through all that stuff years ago. And tested and measured many. All ultimately useless as while a 5 watt one JUST provide enough power in summer, as long as panel is OUTSIDE the vehicle (vehicle glass removes much of the power) and aimed south at around a 30 degree angle. It does almost nothing over half the year.

Its not just dahl. Its all new modern cars with endess other eletronics all having a small drain. It add up. All those computers, radio recievers, for remote locking etc and radio and engine management computers, and th battery natural self discharge.

I eventually siliconed a 50 watt panel on my roof, with charge controller set to 13.8V in winter, and 13.4V the rest of the time. That works great. Battery always topped of. At least 10 months of the year. Still inadequate in deep winter.

Other stuff you might read. https://www.wheelchairdriver.com/board/ ... =3&t=10001
And https://www.wheelchairdriver.com/board/ ... f=3&t=9648

I think the simplest way to keep the battery topped up is to take it on a 10 mile trip around my town at least once a week if I'm not using it for the rest of the week. A lot less hassle than having to go through all the expense and trouble of fitting in ways of charging the battery. I did purchase a battery charger a few weeks ago. If I need to put it on a charge, then I will use the charger. I think you're right about not charging very well in the summer. My house is south facing, but my vehicle is parked on the opposite side of the house, and therefore it would be challenging to locate a solar panel where it will catch the sun during the wintertime

A battery takes 16 hours to FULLY charge if heavily discharged. In the begining vehicles had a simple coil, points and few electrics. All of which were disconnected when you remove the key.

Starting a car on a 100% FULLY CHARGED battery takes 1 to 2% from it. In other words its still damned near full. The alternator can put that tiny bit back over a couple of hours driving. But its not important to do that as its almost full anyway. So little sulfation and battery lasts a long while. That was yesteryear.

In 2021 thats not the case. You battery uses about 60Ah if it gets to low to start a car over 2 weeks. That means to fully charge it which is now essential as its highly sulfated (sulfation is a consequence of the chemistry, and is removed only by charging as soon as possible). If it sits around for days or longer it becomes PERMANANT sulfation. Now the battery goes to the rubbish tip.

Worse than this is that the battery is likely not a deep cycle battery. So this level of discharge over a week cuases severe life shortening. So maybe under a year. And driving it 10 miles will not fully charge it or even get close. It really does take 8 hours to get it to say 97%. But thats not enough to remove all of that long term sulfation you aquired all week at 30 or 50% charged.

So while doing that 10 mile a week may keep it starting (till its battery dies from sulfation and being used as a deep cycle battery) it isnt the answer.

During the couple of months in winter that the solar on the van roof is inadequate I connect it via a long extention cable down the side of my house to a charger in my bedroom. It is set to 13V. So it never drops lower. And the solar overtakes it periodically and charges at 13.6V.

I don't do an awful lot of driving nowadays. Maybe it's going to be a case of having battery problems all the time now.

That exactly why I have a solar panel 50 watts, and a charge controller. And why I add a battery maintainer over the darkest 8 weeks. Because that keeps my battery 100% charged even if I drive 4 times a year. Or never!

Current odyssey battery fitted when the original died in a year. Odyssey now 12 years old. And still fine. Guess why.

Ironside wrote:I was wondering whether it would be possible to plug a small solar panel into the cigarette lighter in order to keep the battery charged. I have a similar system on a leisure battery in my back garden that keeps a battery charged for the electric winches on my radio tower.

How does it work on the radio tower? I'm thinking about my van battery now the weather is colder. It's dark at 5pm for the next few months. And I don't have any type of outlet to connection a charger. If I ever get this 8s pack together I should think about using it to charge the van battery. I think I can do it with the pl8...or maybe even the ISDT. Need to ask for help to wire a connection to the vehicle battery.

Over winter you need a constant 13.25 to 13.40V ideally for long term float.. And it only need only be very tiny like half an amp. 500ma. Like a wall wart or something.

How to connect? Direct to the battery. IF your cigar lighter or accessory connector stays on with keys removed then you could use that.

Personally I think an anderson connector under the wheel arch, is the best way. Because you can fast charge the van, or start it, or use it to power any number of things like a PL8 or other hobby charger too. Works both ways.

Burgerman wrote: If your cigar lighter or accessory connector stays on with keys removed then you could use that.

No such luck. Need to talk my brother into wiring up a connection.