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flywheelz avatar image
flywheelz asked

Blue Smart Charger Problem End Absorption

Hello, I would like to report a problem. This was observed with Blue Smart Charger IP65 12V/15A and 12V/7A chargers.

When the Absorption stage reaches towards the end with the current dropping to 0.3A, the charger starts cycling the relay on/off. Sometimes it enables then disables the relay in less then one second. This goes on for hours. It looks like its stuck in a loop. Relays have a limited life cycles.

I am able to stop the death loop by changing the charge voltage down by 0.20v for a minute then raise it back 0.30v, this stops the issue. Eventually it goes to Float mode. Using the latest Firmware v3.25 Bootloader v3.15.

Here is a VRM graph that shows the problem outlined in red box. Then you can see I lower the voltage from 14.7v to 14.5v then a minute later raised it to 14.8v this stops the relay cycling.

Please add a delay/hysteresis or change cut off points to the charge algorithm.

Thank you.


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charger
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1 Answer
Lambertus Gorter (Victron Energy) avatar image
Lambertus Gorter (Victron Energy) answered ·

Hello Flywheelz,
The cycling of the relay at the end of the absorption phase, is known behavior. We use high quality automotive relays in these chargers and the current that gets switched is very low. These relays will easily last the lifetime of the charger.

There is no need to worry about the relays wearing out from this.

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