Smartsolar MPPT 75/15 behavior

[George48976]

Hi,

Lately noticed when charging from full sun that wattage jumping from 2w to 80w rapidly even though sun brightness remains constant. This is an intermittent problem.

Normally when going from bulk to absorb wattage drops and remains fairly constant but this issue is causing wattage to go from 2w to 80w every second.

Picture attached

 

[George48976]

Also voltage goes to 14.6v in absorb mode even though set at 14.1v for my vrla gel batteries

 

[geem]

It's faulty. Had one fail on me. It was replaced under warranty. Also had a b2b fail. Also replaced under warranty. Electronics on boats not all they are cracked up to be

 

[George48976]

Thanks for the reply.

I swapped it out with my spare controller unit which behaved the same. So in my case it seems this is normal as it happens near switching to float mode on both units.

 

[RupertW]

Thanks for the reply.

I swapped it out with my spare controller unit which behaved the same. So in my case it seems this is normal as it happens near switching to float mode on both units.

Interesting- I haven’t seen behaviour like that ever so I wonder what the battery voltage graph looks like at the same time - that ability to show two different figures at the same timeom the same graph is so useful. Normally once it reaches absorption the battery voltage is steady with very slowly declining watts before suddenly and completely dropping down to float.

Sorry - can’t remember whether you have FLAs. If you have lithium with their own BMS then you might be watching the behaviour of that.