Simple fast charging

[ChrisB]

Hi Evan

Must admit I did wonder about the reverse charge regen thing being a recipe for the magix smoke but dont like to stop folks from thinking sideways.

With the fast charge option would need to have the van powered as well i.e mains on the normal input or is it good enough just to have power on the fast charge terminals and thus this brings the controller on line to count the ah going in ??

I like your comment about not being legal to sell I think I can see why looking at the pic on the site

Is it possible you could suggest components for such a build ?

ChrisB

[EVan]

With the fast charge option would need to have the van powered as well i.e mains on the normal input or is it good enough just to have power on the fast charge terminals and thus this brings the controller on line to count the ah going in ??

The calculator always runs, but why waste 3kW of charger, is my opinion. Also, letting the car charger handle the gassing stage is sensible.

I like your comment about not being legal to sell I think I can see why looking at the pic on the site

That one would be OK to sell, technically, as it uses off the shelf supplies which are CE marked. I built another supply from scratch, which wouldn't be EMC compliant, and bought a third, which also isn't EMC compliant.

Is it possible you could suggest components for such a build ?

Well, several 50V switch mode supplies are a good start. Or a big transformer and rectifier if it's going to be stationary.

An ultra-cheap idea I haven't tried yet would be to use half a dozen immersion heater elements in series with a big bridge rectifier. As long as you have a use for lots of hot water at the time you're charging, it'll even be efficient.

[arsharpe]

Hi Evan,

Thanks for the detailed reply.

Buy or make a current source (say, 50A).
Rig it to turn off at 200V. Connect it to the external charge terminals.
Keep an eye on it when it's charging, using evlite.

I assume that the 200V is a point before the knee at the max charge point ?

Would anyone suggest a good current source ?

[Flying John]

Hi Evan,

Where do we apply this high current DC source, is it direct to the terminals exposed under the "tin lid" of the controller, or do we need the fast charge lead or access to another set of terminals on the charge socket ?.

JOhn

[retepsnikrep]

Well Gents I have two 3kw 50v x 50A server power supplies going begging, they are very similiar to those Evan used in his set up, in fact he got his from me!!

I know Jim Fell also has some, as does Dennis Doerfell because I bought a job lot several years ago, and dished them out free to BVS members at the time Evan, Jim & Dennis.

You could approach the other two to see who is using them and try to get them.

They are top notch supplies made by Farnell/Advance and cost a fortune new. e-mail me at peterATsolarvanDOTgotadslDOTcoDOTuk

It's buyer collects though as they are bloody heavy.

I used two in series to charge my van in the past. Two made a nice 6kw charger. I even hacked into one and controlled it using Cedric's BMS as they have an output voltage adjustment of approx 45-55v. Again two make a very good 110V 28 x 200A HiPower lithium cell charger.

Evan are you still using yours?

[arsharpe]

Thanks Pete.
Sounds like some useful info.
I have looked at Farnell, but no luck so far - if you have a part number that would really help.

I have emailed you as requested.

[retepsnikrep]

Actually I think I got the output voltage wrong. I seem to remember now it adjusted from from about 48-60V approx. I also have the data sheet for the supplies I believe.

Two old pics I found

www.solarvan.co.uk/offboardcharger.jpg

www.solarvan.co.uk/psu.jpg

Ignore the stupid google warning!!

No e-mail received from you yet Robert.

[EVan]

Yes, Those are indeed the ones used in the fast charger shown, thanks Peter, (and I still use it). As Peter says they would be prohibitively expensive new, and also somewhat old and no longer available, although similar supplies are. You need 4 of them for a Berlingo charger and a hefty mains supply.

[EVan]

Hi Evan,

Where do we apply this high current DC source, is it direct to the terminals exposed under the "tin lid" of the controller, or do we need the fast charge lead or access to another set of terminals on the charge socket ?.

JOhn

If you follow the cable you will see that one end goes to the charge socket and the other to the external charger terminals on the controller. So either.

[EVan]

Actually, thinking about it, I only rarely use that big charger now.

The reason is, that my newer fast charger is much lighter and will work from a 32A outlet, or two 16A outlets, or at a push two 13A domestic sockets, which overall makes it a lot more versatile even if it's not quite as fast.
So I use that whenever I need to charge when I'm out, and the big one remains at home for the odd occasion where I come in and immediately need to go out again, or if I've forgotten to plug it in the night before.

So, if anyone wants to offer me something for it, I'd consider parting with it - the supplies of course being free, you'd be paying for the case, the control circuit, the cabling and of course the fact that it's built up and ready to go.

Drop me an email if that's of interest.