Charger 3kw and 2kw?

[Richo]

The TC chargers are cheap for what they are.
Unfortunately it is hard to compete on price with the TC chargers.
Which is why I asked about the cost some time back and didn't continue.
But it's obvious that they wont do what you would like them to do.

The Meanwell LED power supplies have CC/CV output.
Depending on variant you can have adjustable voltage and current.
Some you can set with the built in dials others need PWM or voltage to control it.


The only other way would have been to use an off the shelf 3kW 48V PSU and then have a separate custom 3:1 boost converter to control/set the current and voltage.

Neither of which would be particularly cheap or easy.

[Paul9]

Thanks Richo,

I think I will buy both a 3.3kw and a 1.8kw charger and leave it at that.

Cheers
Paul

[Paul9]

Thanks for your help so far!

I sent an email off to TC-Chargers asking for a price for both a 3.3kw charger and asked them if they have a 2.2kw charger because I have only seen info on their 1.8kw charger. I told them I am after 38cell x 3.6v = 136.8 max voltage.

Their reply was (including misspellings):

"There is HK-J-H132-32 which max output voltage is 132V. HK-J-H198-23 which max output voltage is 198V.

The max output voltage of your battery pack is 38*3.6=136.8v. There is no suitable model for you unless you reduced 2 cells to match HK-J-H132-32. OR add 2 cells to match HK-J-H198-23. Dont ask why. Cuase it is our configuration.

If you want 2.2KW, we can limit output current. Then you will have smaller power."

My thinking, about which I would appreciate your comments, is that at present I have 36 cells and my two chargers get the pack voltage up to 124.3 = 3.45277 v per cell. I think(?) the 198v chargers would be way to high for my pack even with the two new cells. Then again I intend sending the EV Power BMS back to be reconfigured for 38 x 3.6v = 136.8.

I am wondering if buying the 132-32 would be best. It would get the pack up to 132v or 3.4736v per cell which is marginally higher than the existing max cell voltage of 3.45277.

I think they are also saying that if I want a 2.2kw charger then I would have to buy a 3.3kw charger and have it dumbed down to 17amps max?

Any comments?
and thanks in advance,
Regards
Paul

[coulomb]

I think(?) the 198v chargers would be way to high for my pack even with the two new cells.

It's not too high in the sense that it would not damage your battery. In fact, it's a 3300 W charger capable of 23 A, so it starts current limiting at 143 V, not much higher than your maximum battery voltage. Assuming that your battery can still take maximum current at 3.45 VPC, that's a total of 131 V, so you'll still get 131 x 23 = just over 3000 W from that 3.3 kW charger. They seem to have compensated for their very wide voltage gaps by making the back end current limit reasonably high. So as long as you can get 13.5 A or so out of your charging opportunities, this isn't such a bad charger.

I think they are also saying that if I want a 2.2kw charger then I would have to buy a 3.3kw charger and have it dumbed down to 17amps max ?

Yes, but my understanding is that you'd like to have some 3.3 kW at home, but be able to dial it back to something near 2.2 kW for opportunity charging from a 10 A outlet. It's frustrating because their older models used to have the capability you need.

So maybe your best bet is to look around for a second-hand 3 kW TC/Elcon charger with the ability to cut back charge current (and hence, maximum mains power) by a voltage on the enable input. [ Edit: but then unless you are very lucky you will have to to muck about with firmware modification to get the voltage and profile you want. ]