question

vincentduncan avatar image
vincentduncan asked

Blue light blinking / Charging may be slow?

I have a MTTP 100/20 controller charging a 100Ah LIFE PO4 12V battery from a 120W 24V panel. In full sunlight a get a maximum of about 75W. The Bluetooth app says that I am in bulk charge but the blue LED on the MTTP is blinking. The manual says a blinking light means that the unit does not have enough solar energy to change the battery. The battery will eventually charge but it seems to be slow often taking more than a day under minimum load conditions. Why is there a conflict between the blinking blue LED and the power intake of the battery? Shouldn't I be getting closer to 120W of charge?

MPPT Controllers
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
wkirby avatar image
wkirby answered ·

There are two different blink patterns for the blue LED.
When there is not enough PV power to charge the battery like at night time, the LED blink on briefly every three seconds. It is mostly off with a short blink on.
When it is in Bulk mode the LED should either be constantly on or mostly on, briefly blinking off every 4 seconds. If it is receiving data from something in a Bluetooth VE.Smart Network or external control from ESS when connected to a GX device then the latter blink pattern will show.
Do you have the MPPT set up in VE.Smart network with other MPPT's or a BMV or Smart Battery Sense?

As for not getting 120W, there are many environmental variables to contribute to this. Heat and panel incination are major contributors to not reaching nameplate output.
It's a rare and pleasant event for me to see the full nameplate power from any of my arrays even in full sunshine. On the other hand it's possible to get 140% of nameplate power under certain conditions.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

vincentduncan avatar image
vincentduncan answered ·

Thank you wkirby. Yes I do have my MTTP set up on a network. The second blink pattern is the one I am seeing and based on your comments, I will stop worrying about my system. Thanks once again!

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.