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kcrtechy asked

Charging pattern of a 250/85 MPPT Smart solar reg

I am very curious as to why this new 250/85 solar reg commences charging and ramps up the output to effectively follow the load and then suddenly there is a "click " from the regulator and the output drops to zero.

Is this normal as it is NOTHING like I have ever experienced with a charger being either a Mains unit or a solar regulator as every one I have ever come across effectively follows the load. This is going from Float mode to a 1000 watt load on a 24V bank. It goes up to 38A @26V and suddenly stops, waits for a while and then restarts WHY is it so??

PV Solar Input is 170V O/C charging a 24V Lithium battery (LiFePo4 type). PV volts drop to around 150V on load so the regulator is NOT being fed with an excessive voltage.


We are using this to maintain a 2200watt Victron inverter to power our community radio studios so we do NOT have to rely upon an erratic AC mains supply with frequent short breaks which upset the various computers and modems we use.

MPPT SmartSolar
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1 Answer
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kcrtechy answered ·

An update...ALL sorted with some help from the supplier.

The "Clicking" was NOT coming from the solar reg but from a 70A DC circuit breaker in the output line to the batteries and I only found it because I happened to have my hand on the thing when it went CLICK.

DID NOT trip the unit which is what I would have expected when it clicked but at that stage I was only pushing 25A into the batteries having wound the solar reg output well back.

It went click again and the solar reg recommenced charging.

Hooked my volt meter across the CB and it showed about 80mV and then Click and voltage that jumped up to 4V which immediately pushed what the solar reg was seeing up to a tad over 28V so it backed right off.

Had I noticed that on what the App on my phone was showing I might have nailed this problem sooner.

Result is a faulty CB which has been removed and replaced by another and all is well.


Great Solar charger. Very happy at KCR Radio.

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