New to forum - Off-grid summer home user

[Riley Hoyt]

Hi Folks -

I'm new to this forum as of today. I have had my off-grid system for about 5 years now and been a member of other forums however their traffic has dropped off and I am looking for a more active community. I can answer some questions on solar and have lots of experience in communications systems.

I am a retired tech worker with experience in electronics and software design. I did have my system installed by a pro but I have always been active in the requirements, design and maintenance. My system is as follows:

• Conext XW+ 6048
• Conext MPPT 60 150
• Conext AGS
• Conext Insight gateway for remote monitoring
• Rolls 48V FLA 428AH battery bank (L-16 form factor)
• 3.1KW Solar panels

See you around.

Riley

 

[Hedges]

Welcome.

My system is grid-backup with SMA, similar capacity of L16 SunXtender AGM.
Those batteries want 0.2C charge rate, which I'm able to deliver.

I would think your FLA want 0.12C, and your gross PV STC rating is about 0.14C of bank capacity.
In winter, would be less.

How well are the batteries maintained with that charge rate? Or is my understand of 0.12C not correct for them?

 

[Riley Hoyt]

The batteries want to be charged at 10% to 20% of the 430 AH capacity or 43 amps minimum (different terms but I think we are talking the same thing). The manual states 10% to 20% with 15% of the C20 rate being ideal.

I can charge them at very close to 40 amps. I think about 38A and they seem to be holding up fine.
The system is not used in the winter time as it's a summer home.

I was worried about the bulk charging rate being too low but other experts elsewhere commented that it should be fine.

Once and awhile (rainy days), I charge them at 50A->70A with my generator to give them a good stir.

I should add that I would like to see more power from my panels. One day I will upgrade them.