Blue smart charger 12v/5a low current

Q&A and troubleshooting
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1

Hi, having car battery with low voltage (but was also checking that for other two batteries).

The thing is that despite correct voltage current is very low. Low battery in bulk mode (5a) is only for about 1ah or sometimes less, then it goes to absorbtion 14.4 with current of 1a, sometimes less. In this rate I will never charge 50ah battery. Now doing recondition charge and it is only 0.6a.

Somehow some cheaper charger from popular market (lidl) with 4a, makes things happen faster and more reliable, definitely should not be the case. Software is 3.61, bootloader 3.15, serial no is Hq2113G4J6U. It has some years but was used relatively rarely. Is there a way to have charger work more in bulk?

2

If it is getting to 14.4V and 1A quickly then either.

  1. The battery is fully charged.
  2. The battery is at end of life.
  3. You have a poor connection from battery to charger with high resistance and voltage drop so the charger sees 14.4V even if the battery itself is at say 13.2V.

The charger is working correctly, if the terminal voltage is correct yhe charger only produces the current the system demands. If it put more current in the voltage would need to increase above 14.4V. The reason the cheap charger could work is if it is not voltage limited and is putting in say 15+ Volts.

3
  1. Battery is not fully charged.
  2. It was not only on one battery, other one I checked and similar behaviour. Plus other charger uses more amperage. Next week will check it but for sure it is not giving 15v+.
  3. Standard connection with standard cables of Victron. This is only 5a charger, so nothing fancy. It goes into bulk, but this bulk can last only up to one hour. Beginning with 5a, then decreasing. Cables are not hot.