## I would like to set the charge current lower than 5A

Sandrosan
Posts: 43
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

### I would like to set the charge current lower than 5A

Hello everyone,

My name is Sandro from Milan Italy and first of all sorry for my poor English. I own a Citroen C zero of 2011, I bougth it in 2017 and it has just 22000 km.
I made an EVSE using this PCB https://www.ev-power.eu/Electric-Cars/E ... cable.html

because I need to adjust the charging current according to my Solar PV production and my home loads consumption.

Using that PCB the min charging current is 5A and the max is 14A with steps of 1A.
Lower than 5A the EVSE stops driving the OBC of the car, so there is no way to charge the car with less than 5A at 230V.
In winter my solar PV does not produce too much but I would like to use also the small solar production that is like 1 to 4 A (at 230V).

Is there anyone that has find out the way to charge the Imiev / C zero / iOn with lower current than 5A at 230V?
Thanks in advance to all will help me.
ciao
Sandro
Gary12345
Posts: 55
Joined: Tue Feb 12, 2019 4:15 am
Location: Essex, UK

### Re: I would like to set the charge current lower than 5A

Hi there !

The charger will just not run at such low amps and it is very inefficient. There is a 600w overhead during charging, this is from running the electronics, voltage conversion, water cooling pump, monitoring and balancing inside the battery, etc.

That means at 240v approx 2.5A is used by the car managing the charging. The longer you charge the longer you are wasting 600w, the more total power is wasted.

If you could make it charge at 4A
4A @ 240v = 960W consumed, minus 600W = 306W going into the car, very little. Below 4A almost nothing would go into the battery and it would take days to get any charge at all.

Put the 4A into your hot water tank!!!

Thanks.
1kaspars
Posts: 17
Joined: Tue Mar 28, 2017 10:39 pm
Location: Latvia

### Re: I would like to set the charge current lower than 5A

Maybe 230V to 110V transformer could help?
EU 2012 I-MIEV owner for 24months, 24'000 miles driven, odom 56'500miles, 38.5Ah left
1kaspars
Posts: 17
Joined: Tue Mar 28, 2017 10:39 pm
Location: Latvia

### Re: I would like to set the charge current lower than 5A

Gary12345 wrote:Hi there !

(..)
There is a 600w overhead during charging, this is from running the electronics, voltage conversion, water cooling pump, monitoring and balancing inside the battery, etc.

That means at 240v approx 2.5A is used by the car managing the charging.
(..)
Car consumes 0,4-0,5A @333V while in ready mode and no other 12V consumers are on. While charging yes, i have seen 1,4kW goes in to the battery while 2100w from 230V wall outlet. I hope Canion have error in that reading.
EU 2012 I-MIEV owner for 24months, 24'000 miles driven, odom 56'500miles, 38.5Ah left
dracekvo
Posts: 33
Joined: Tue Sep 11, 2018 12:18 am
Location: Czech. Rep.

### Re: I would like to set the charge current lower than 5A

I use 14A carger. 3000W.
If I see on canion, he show 2400W to battery.
kiev
Posts: 1778
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

### Re: I would like to set the charge current lower than 5A

Has anyone put a current clamp on the 12V output of the DCDC while charging?

i don't know the minimum output current, but 40A at 14.4VDC doesn't seem out of the question to supply power for

charging the aux battery,
holding relay coils,
power to all the ECUs that need to be active,
power to IP and other items on the CAN buss,
12 CMU boards,
2 Main contactors coils,
coolant pump as needed,
etc???
kiev = kenny's innovative electric vehicle
Sandrosan
Posts: 43
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

### Re: I would like to set the charge current lower than 5A

Gary12345 wrote:Hi there !

The charger will just not run at such low amps and it is very inefficient. There is a 600w overhead during charging, this is from running the electronics, voltage conversion, water cooling pump, monitoring and balancing inside the battery, etc.

That means at 240v approx 2.5A is used by the car managing the charging. The longer you charge the longer you are wasting 600w, the more total power is wasted.

If you could make it charge at 4A
4A @ 240v = 960W consumed, minus 600W = 306W going into the car, very little. Below 4A almost nothing would go into the battery and it would take days to get any charge at all.

Put the 4A into your hot water tank!!!

Thanks.
Hi Gary 12345,

Thanks for your comments. I know the efficiency will be low, but better than noting. I will not use such low charging current for charging the battery completely but just to improve the SOC a bit.
Than let me think that 600W overhaed is too much and probably it will be just for limited time.
I already have done a hot watar tank controlled with 2 levels 600W and 1.2kW.
Sandrosan
Posts: 43
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

### Re: I would like to set the charge current lower than 5A

1kaspars wrote:Maybe 230V to 110V transformer could help?
Probably you are right. I will look for a scrap transformer with min 1kVA for some tests. Thanks for the tip!

However I would like to see if changing the duty cyle signal of the EWSE PWM can force the OBD to charge with lower current.

Maybe some of you in this fantastic forum already done it.
Sandrosan
kiev
Posts: 1778
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

### Re: I would like to set the charge current lower than 5A

It may not be possible to reduce the pulse width any further; it requires a 5% duty cycle for the EV-ECU/OBC to detect that an EVSE is connected and available.

In another thread is a diagram:
viewtopic.php?f=24&t=1497&start=110#p32608
kiev = kenny's innovative electric vehicle
Sandrosan
Posts: 43
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

### Re: I would like to set the charge current lower than 5A

kiev wrote:It may not be possible to reduce the pulse width any further; it requires a 5% duty cycle for the EV-ECU/OBC to detect that an EVSE is connected and available.

In another thread is a diagram:
viewtopic.php?f=24&t=1497&start=110#p32608
I remeber I have seen the pulse width and when the current was already 6 or 5 A the width was so tiny and the next step down switched the signal totally OFF. So I am afraid there is not way to go down playing with the signal.