question

brad-australia avatar image
brad-australia asked

Charging through an MPPT 100/20 with a 24v power supply

I Have a 100/20 Smartsolar MPPT in my vehicle charging a battery to run fridge and light etc. Some times my vehicle is parked under cover for a few days at a time. I purchased a cheap 24v 5a power supply to connect into the PV Input. The 24v Power supply runs from AC,

When the AC is powered up, the input voltage on the MPPT is stable at 24.05vdc the Input wattage starts low and climbs to 120w or so over 4-5 seconds then drops to 0w. Then climbs to 120w or so over 4-5 seconds then drops to 0w again, and continues this cycle.

I grabbed a 48v 4a LED light power supply to try that, it behaves exactly the same.


Any one have any idea why this would behave like this ???


Brad

MPPT SmartSolar
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2 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Sounds like the 20A MPPT is exceeding the 5A overcurrent protection of the power supply.

Have you tried reducing the max charge current setting of the MPPT to 4A in VictronConnect?


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brad-australia avatar image
brad-australia answered ·

Ahhhh, I reconnected, Turned the charge voltage down to 5a works fine

Upped the charge amperage to 7a all good

Upped the charge amperage to 9a all good

Upped the charge amperage to 10a does it again. A small Warning/ note pops up Charger off

When i clicked on this it sayd #OR1 : Insufficient PV Power,


So am I correct tin guessing that this will only work if the charge rate is set below the max output of the Power supply?

Does the Charge rate also limit the power output on the Load output on the MPPT?

Brad

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