Battery Fuse Opening Effect

[haycord]

I certainly understand the purpose of properly fusing the Battery bank positive but my question is in regard to the effect that might have on a Charge Controller(s) if the fuse opened.

Do all Controllers fail if the Solar Panels are on-line with the Controller de-energized (from the Battery)? I ask because it seems to be a SOP to be sure the Controller is energized from the Battery before switching the Panels. Thanks

 

[Mattb4]

Typically you energize the battery first to allow the SCC to recognize it and set operating parameters. It should not hurt anything if the battery fuse to SCC blows or the battery becomes de-energized for some reason. You might see an abnormal reading for battery voltage from the SCC without the battery there. When you go to regain things you would want to follow normal startup procedures.

 

[HighTechLab]

In my experience, PWM controllers are likely to be damaged by an unexpected disconnect - but with MPPT controllers they are typically not going to have any trouble. With the price of good MPPT controllers being so low lately, PWM is mostly disappearing and so are the issues associated with them.

 

[haycord]

I researched a few Controller Instruction Manuals - and I've decided the energizing sequence may be Brand/Type specific. I'm currently trying to help a neighbor make 'what they bought work' and the cheap PWM Controllers specifically state to energize from the batteries first (or suffer the consequences).

It always comes back to 'you get what you pay for'...
Thanks for the comments.

 

[scrubjaysnest]

Looked at a lot of PWM controller manuals over the years all said connect the battery first. This may be the PWM controllers act like a switch. With mppt the input is isolated from the output. Maybe with mppt its a holder from pwm days.

 

[haycord]

Just looked at the RENOGY ROVER ELITE 40A MPPT and it states (Quote) NEVER connect the Array to the Controller without a battery. BATTERY must be connected first.
Interesting...

 

[rhino]

Victron has no issue not being connected to battery while still connected to PV. You technically could even connect a DC load to the controller with no battery and just PV. The manual even specifically mentions doing this but warns you about the algorithm not being able to adjust fast enough to changing loads.. so that makes me wonder if there would be no issues running a resistive load directly connected to a Victron SCC with no battery.