Extending range with additional batteries

[arsharpe]

Hi,

Before I start doing calculations, I just wandered if anyone had already done it.

I am thinking of adding some range extending batteries to my Berlingo.
The idea being:-

- to put the batteries into a trailer that I can attach to the Berlingo when going on a long run. The trailer would contain the batteries low down and the upper part of it would be aerodynamically shaped to help 'smooth off' the poor aerodynamic affect at the rear of the van.

-At a convenient point when there is enough space in the Berlingo batteries, I would stop and use a dc-dc charger setup to fast charge the Berlingo from the trailer batteries, in say 20 mins for a 50% top-up.

-Also, when I am at the destination I can use 2 mains outlets to recharge both sets of batteries.

The sort of questions I need to answer are as usual :-

-How much battery capacity would I be able to fit into the bottom of a small trailer. I assume about 50% of the Berlingos.

-Someone said to me a long time ago that the Berlingo could charge from a DC source. I am assuming that this is the fast charge mode. Therefore I would only need to design the battery pack to supply this voltage.

-I assume that I should be able to get a trickle charger off-the-shelf.

-How much will the weight of the batteries/trailer affect the overall range. (I am hoping that this will be small, because of the benefit of the improved aerodynmics).

-There may even be the possibility of using the trailer with the Prius to make that more efficient on a long run.

-and of course (probably the limiting factor of) the cost. I assume about £2-3k

Regards,
Rob

[Peter Eggleston]

It would be far more efficient if you could just unplug your Berlingo batteries when low and plug in your trailer. I don't know how easy this would be to do on a Berlingo, but it would be easy on my truck.
Peter

[ChrisB]

Interesting thoughts there Rob, however there is one problem that you need to over come first.

The rear pack hogs the space I think where the tow bar attaches, so you would have to redesign the whole way the tow bar attaches to the vehicle.

Yes you could fast charge the batts from the DC input, look at the power lead plug and you will see two rectangular slots , these are the DC inputs.

The trailer voltage would have to be above the vans voltage, also some sort of control would need to be set up to regualate whats fed into the vans battery.

So yes I think it would work but as for the effect of towing the extra weight of the trailer/batts about would have on the range of the orginal berlingo I dont know.

I'm currently looking at a silient deisel Genny to go in the back of the van for extending the range for those times I am likely to go outside the vehicles actual range and I dont know if I am likely to find a power source, this genny would be run on Red deisel or even sunflower oil.
The downside would be it could only carry out the normal slow charge but anything I feel is better than being stuck somewhere.
The added advantage with the genny is I have other uses for it when its not in the back of the van
Interestingly I did a couple of rough calcs on fuel usage on the genny idea and if its run on red deisel its still works out just cheaper than if I was to have a deisel powered van

ChrisB

[Flying John]

I wonder how difficult it would be to tap into the main motor cables and make the van think it is regen current it is getting. So hook up extra batt set greater than normal pack voltage, disconnect one motor cable and then switch on ignition and the controller will think it is regen current appearing on the motor.

Alternatively there are fast charge cables already built into the back of the Avcon charge socket - you can buy in France a fastcharge lead (I think its red) and this connects to a high current DC supply.