Is there something in PCB1.3 stopping from 4A charging?

[markor]

I have 10,4Ah batterypack in my mower. It is rated for 4A charging. The original gives 1,3Amps, so I bought a charger with excatly the same specs as the original which came with the full ardumower kit, except it can give 4.0Amps. However I seem to get only 0,4Amps out of it at 28V. And can't get it to even start charging at 23V.

Original: Input 100V-240V 1.2A, Output 29,4V 1.5A
New: Input 100V-240V, Output 29,4V 4.0A

Both are for 24V akku. Is there something that shuts the charge down when trying to charge with 4amps?

 

[markor]

Ok, I think the Robot was supplied with 1,5A fuse for EF1 and 5A fuse for EF2. The componen list here is talking about 5A and 10A which actually makes a lot more sense. I think I blew the EF1 on the 23V mower. The other one is at 28V and changed EF1 to 5A and EF2 to 10A, but still only 0,3A charging with the new charger. Have to try again on the other one tomorrow after changing the fuses.

 

[brosr]

Can you discharge to 25V. What is the charger current in that case?

 

[markor]

Yes, my mower with 23V left had a blown fuse. I replaced the 1,5A fuse with 5A fuse and now it charges again, but only at about 1,3A just like before. I have also changed the code to correspond the 4.0 charger even if I don't see anything that would help with that.

batChargingCurrentMax = 4.0;       // maximum current your charger can devliver

The charger fuse is now 5amps, so there must still be something that wont allow the amps go up.. I haven't yet figured out if there is anything in these to change:

batSwitchOffIfIdle         = 8;          // switch off battery if idle (minutes, 0=off)
batFactor                  = voltageDividerUges(100, 10, 1.0)*ADC2voltage(1)*10;   // ADC to battery voltage factor *10
batChgFactor               = voltageDividerUges(100, 10, 1.0)*ADC2voltage(1)*10;   // ADC to battery voltage factor *10
chgFactor                  = ADC2voltage(1)*5;        // ADC to charging current ampere factor  (see mower.h for macros)  
DiodeD9                    = 0.36;       // Spannungsabfall an der Diode D9 auf den 1.3 Board (Die Spannungsanzeige ist zu niedrig verursacht durch die Diode D9) **UZ**

 

[markor]

I read the values directly from charge current sensor and tested with the 4A and original 1.5A charger. Both are giving values just shy of 800. So it's not just display error, something is really tuning down the current even before the current sensor..?

int currentADC = readSensor(SEN_CHG_CURRENT);
Serial.print("currentADC:");
Serial.println(currentADC);

1.5Amp charger:
currentADC:773
currentADC:770
currentADC:773
currentADC:772
currentADC:773
currentADC:772

4Amp charger:
currentADC:791
currentADC:791
currentADC:792
currentADC:791
currentADC:791
currentADC:792

 

[brosr]

Hmm, reading the PCB1.3 I see nothing which is limiting the charging current (except the Shuntresistor 0.1Ohm of the INA169). BTW on the INA169 check the solder bridge which determines the current measurement range. Open means up to 2.5A, close up to 5A. This should not the problem here as you seems to be below of 880mA.
Did you ever try to connect directly your charger to the battery (not via PCB1.3) and measure charging current&voltage with a multimeter? I think this would be the best method to check if something is wrong with the battery pack or the charger. Be careful with Lithium battery, don't burn your house

 

[markor]

Thanks for the tips! I don't think it's ina eather, but I'll go ahead and try the 5A. And will try directly to the batteries and see what multimeter says. And always good to warn as it's not the best idea to mess with the batteries! Luckily I have safe areas (fire proof doors etc) for that and very well equipped with extinguishers, fire blanckets etc. ;D I'll just do a quick measurement without PCB, before the batteries know what even happened. Not gonna leave charging like that.

 

[markor]

Ok, did some measurements. I put the multimeter in series with the positive out from PCB to batteries while charging. After all it seems to be a faulty reading from the current sensor. When watching from the console or mobile app, it says 1.26Amps, but the multimeter after PCB1.3 and before batteries says there is actually 3.91Amps going for the batteries. So nothing is preventing higher current from flowing through, but it seems the current sensor on PCB1.3 can't output or measure values much over that 1.26Amps. Have to see if it can be corrected and how will it affect the stop charging code etc...

Edit: I soldered the JP1 on INA169 for 5A, but now the software is saying the current is 1.19A. Which is less than before the bridge. Multimeter before batteries still saying it's actually close to 4A going through. Don't quite know what to make of it.

 

[brosr]

Which FW are you using Azurit or Sunray? Azurit has 0.1A, Sunray 0.2A battery full current where charging is terminated. But if we can't trust the current sensor.... With the 4A charging current u should see 400mV at the INA shunt resistor. BTW. The Azurit FW has an ADC calibration feature which you can run (without charger connected). I was doing save to memory and reboot (don't know if this is a mandatory step).

I'm currently building up my Ardumower (see my thread about charger disconnect). At the weekend I will do also some measurements. I have the standard battery/charger combination. Will check if the FWs will give correct values.

 

[markor]

I'm using Azurit. I have set the stop charge current to 0,1. The new charger is blazing fast compared to the original. Funny thing is that the amps shown is acting just like they did with the original charger. As if the readings are just scaled down. I've been monitoring the charging and I'm now reading 28.55V and 0.60A, so I assume I will shortly be getting below 0,1 amp readings and all will be well.

I have already done the ADC calibration as instructed, but I thought it was only related to perimeter sensing. I can try that again..