I am driving my Vanden Plas much less than before, and from time to time so little, that in spite of an healthy electric system, the battery drains too much after weeks of non-use.

So i have grown accustom to simply disconnecting it once parked up, but it is not ideal.
Need to lift the floor board every time, bit of an hassle if there are things in the trunk.

But, me was not me, if I was not thinking about an easier way, and I stumbled upon this neat looking remote operated device.
I can see it perfectly mounted against the side board, fitted in the battery's ground strap.

Any experience or opinions?

PS. A tender is a non-option for me, no electricity I can tap in.

 

Eric that looks an ideal solution to your issue. My only concern would be pocket activation while driving! Is your car stored outside for any length of time, spotted a solar panel battery tender that looked handy.

 

I'd go with a mechanical one.

 

Yes I too pondered a toggle switch install. But the idea of having to reset everything so often, helped me choose to get a tender.

 

Ha, thanks guys, something to consider I did not think about ... more research to do .

 

The electronic battery disconnect you posted seems pretty good. However, it is for 200 Amps continuous which is not enough for the starter motor. It is advertised to be good for 1,000 Amps peak (very short time) which certainly well covers the starter motor current. The question is how long it can handle the current during engine cranking, some 300-500 Amps I guess. It may be a problem if you have to crank the engine for a longer period of time to start it - the device may start cutting-out as it probably has overload protection (otherwise it may burn). Another disadvantage is that, even when it is in the disconnect mode, it will draw some small current from the battery to keep its receiver alive. Hopefully, this current draw is small enough and good for some 3-4 months of car sitting.

If you want robust connection and no current draw when disconnected, you can look for a latching relay of at least 500 Amps. They can also be remotely operated by a switch of the same type as the widow switches - brief press "up" will engage the relay and brief press "down" will disengage it. The latching relays need the polarity of the control voltage to be swapped in order to engage/disengage, just like the window motors. I have this setup on one of my cars using a 100 Amp continuous (500 Amps 30 sec.) latching relay (Intellitec, see pic). This rating is enough as I am not totally isolating the battery but just isolating the positive feed to all the car's electrical/electronic devices and the main positive cable to the starter motor remains connected to the battery (there is no current draw there). Latching relays of higher amps (like 300-500 Amps) are available but they are quite big and rather expensive.

 

You might try to locate an original BATTERY ISOLATION devise that Jaguar used when shipping the cars.

They were to be disconnected and returned to Jaguar when the car was sold.

Not all were returned. I have a few that I found in the Jaguar shop. Each car had a different one or style that fit the location of the battery and the wiring harness connector used.

You can use something like a starter solenoid to connect the high load of the positive post. The WHITE/BLUE wire in the boot near the battery will provide a GROUND or EARTH when the ign key is switched ON.

That is how the original ISOLATION RELAY worked.

bob

 

About the electronic "Battery Doctor 20395", I said "seems pretty good" but this was after reading the adverts and the brochure. Just found some customer reviews and it seems 50-50. See: .

 

Granted, I have a fairly new battery, but I have left the car unused, without a battery tender, for a month at a time without any problem. But, I would use a tender rather than a switch. You can connect it to the hot terminal in the engine bay and any metal connection for ground and you can even close the hood too.

 

Those are some very useful considerations, how even a simple device can get 'complicated' quickly ... much appreciated, and thanks for the Amazon review link!

Yes, I have always been interested in the original shipping isolator, even have the schematics somewhere.
However, what I like about the switchable device is that it is in my own control, keeping it on for the weeks I use the car more, then switch it off if I think it will not be used for a while.
Your suggestion on using a starter relay to replicate the OEM one is interesting homework though, thanks!

I think a month is about what my car survives, but after that it is game over.
The sleeping current is within the acceptable range (I remember some .35A at full sleep), but it still is a matter of time till the battery surrenders.
And as mentioned, there are no power plugs in our garage, and even tapping into the lighting system is not easy (all hidden in the concrete).
Yes, I checked that too LOL.

 

I wouldn't use a starter solenoid as battery isolator for two reasons: it draws some 5-10 Amps when engaged and because its coil is not designed for continuous use in the "on" state but for brief usage during engine cranking. In continuous use, it may overheat (not a problem for short drives during shipping of cars).

The latching relays do not draw any current when in "on" (or "off") state, only during the momentary switching them on or off. The "Sterling" latching relays seem to be the top of the range (see attachment); model ELB12240 would be the right one for car battery isolation.

 

Well, as mentioned, this went quickly from something "simple" to quite some thoughts and possible consequences ...
Thank you all very much for the input, some issues I had never thought about, and the Amazon reviews helped as well.

Also not in favor of building something very complicated for what is basically as simple as 'on' or 'off', so I just ordered the most simple cutoff switch I could find.
Not exact what I want, but better than what I do now ...