[MoonUnit]

I believe the CCS protocol has a minimum voltage level of 200V, and that Chademo is similar (may be lower, I'm not sure). I run 5 Tesla modules in series so when discharged my pack voltage is c.96V, and max's out at 125V.

Does anyone know of a means to use CCS with such a low pack voltage?

I note: 'normal' CCS seems to be able to supply 50KW, but that would be at 400V (I think max current in the protocol is 125A). I'm not expecting to be able to charge at 50KW when my pack voltage is so low, but it would be very useful if I could connect to DC charging stations and make use of CCS, even if my charge rate were low (say 10KW).

I also note I may not be very popular charging at 10KW on a public CCS charge point, but that's a different consideration!

 

[DomT177]

Either a) use a 400v DC DC converter, expensive ( and I don’t know of one that exists ).

or b) change the pack for a full voltage pack

c) use a faster AC charger, maybe a 22kw one would suit.

from what I read on the side of an ionity CCS unit, their min voltage is 150v

 

[john61ct]

Split the pack, put in a set of contactors

in series for charging at double voltage

back to parallel for discharge.

Yes, barely practical I know

 

[brian_]

c) use a faster AC charger, maybe a 22kw one would suit.

I agree - if charging is only going to be at 10 kW, just use a large enough onboard charger, and be able to charge at that rate at a much larger selection of charging stations (since 10 kWor higher Level 2 AC charging stations are much more common than DC charging stations).

 

[brian_]

Split the pack, put in a set of contactors in series for charging at double voltage back to parallel for discharge.

Yes, barely practical I know

That's actually what GM has chosen for high-voltage Ultium vehicles such as the GMC Hummer E; in their case, it is the other way around, to allow charging a pack designed for up to 800 V charging at only 400 V). It makes sense, but of course has a complexity cost.

 

[brian_]

Either a) use a 400v DC DC converter, expensive ( and I don’t know of one that exists )...

This is similar to Porsche's solution for charging the Taycan (designed for charging at up to 800 V) from 400 V DC sources - the opposite direction to what is needed here. Their onboard converter has 50 kW (base) and 150 kW (optional) power ratings. Anything like this will certainly be expensive.

 

[remy_martian]

I agree - if charging is only going to be at 10 kW, just use a large enough onboard charger, and be able to charge at that rate at a much larger selection of charging stations (since 10 kWor higher Level 2 AC charging stations are much more common than DC charging stations).

More common? The only public level 2's I've noticed are at the Chevy dealer and an employee always hogs it to charge his commuter. That said, hotels and employers run Level 2's, so maybe you have a point.

Splitting the pack for double (or half) voltage charging makes sense, though, and is not that much more expensive if designed in from the outset.

 

[MoonUnit]

Thanks everyone. Some responses:

My pack is already in series and I can't reconfigure to a higher voltage for charging.

I'm in the UK, and there are plenty Type 2 6.6KW chargers in the towns but the motorway service stations sometimes have only CCS / Chademo. I have a friend who's right on the limit of my range and the major service station bang in the middle of the journey has no Type 2 chargers at all. Only CCS and Chademo. Being able to charge here would really help.

22KW AC is possible if I buy two more chargers, but the question is about whether a means exists for DC charging at low voltages.

I am intrigued by the idea of a DCDC converter to boost my pack voltage to something CCS can work with.

 

[brian_]

I'm in the UK, and there are plenty Type 2 6.6KW chargers in the towns but the motorway service stations sometimes have only CCS / Chademo. I have a friend who's right on the limit of my range and the major service station bang in the middle of the journey has no Type 2 chargers at all. Only CCS and Chademo. Being able to charge here would really help.

That makes sense.

 

[remy_martian]

^^ No, you actually want to drop the voltage from CCS to the pack, not boost from the pack to CCS.

 

[yourmate]

OMG! Everything sounds Chinese to me
OK. Absolut idiot, I know there are electric cars I even saw a few IRL. I know that you can charge them at charging stations. Pretty much that's what I know so, please be patient. Thanks

Apologies for the hijack but my question is completely related (or it's just my ignorance)

So I converted a panel van to a camper and have a 24V battery system in a 2S2P configuration - 4 x Valence U27-12XP 12V 140Ah so the overall wattage is 6.7kWh. I have solar, DC2DC and shore power charging and I use Victron equipment.

Would I be able to implement a charging protocol/equipment to be able to charge this battery pack on the road if needed @ an EV charging station? Is it possible? Would this be a huge financial investment? Is it a completely dumb idea?
The battery pack could be charged @ C rate (140A) if needed without damage according to the manufacturer but C/2 is recommended.

Thank you

 

[remy_martian]

No. It's illegal for you to park in a vehicle charger stall.

 

[yourmate]

No. It's illegal for you to park in a vehicle charger stall.

I reckon it does not matter whether it's a free charger or a paying one.
At least I figured this out very quickly
Thanks for the help!