Boat: Is my MPPT the right size?

[FlyingTeapot]

Hi everybody, new to all this and finding my way slowly. I'm on a Boat!

My system is based on Will's "not hard" Video, and the Input/Storage is:
(4) Renogy 200W panels and (4) Renogy 200Ah AGM's. Victron everything in between.
So, 800Watts going into the MPPT, and 800Ah of Battery.

I'd originally spec'd my solar "palapa' for (3) 175W panels, and became unsure:
Is 800Watts and the input Voltages okay for a Victron MPPT 100/30?

First post, lots to learn and I appreciate your time and advice.

FT

 

[Merl Priester]

Your 4- 200 watt panels are rated in series to just under 90V but if you are in really cold weather you might get close to the 100v limit. I would install them as 2 in parallel and then series the 2 parallel banks. I assume you are using 12v here and paralleling the batteries. Put a 15 amp inline fuse on each series of panels and a dc rated breaker of 25 to 30 amp on the line coming into the charge controller. I would get a 100/50 instead as you will get more power. I have 800 watts on a 150/60 Victron and get sometimes 40 amps to the batteries. Not a big price difference.

 

[Mattb4]

Would help if you gave panels Voc but at a guess they are ~23V. Therefore 4 in series would be 92Voc. This is below the Victron's 100Voc, and since your location seems to be Baja, cold weather voltage increase is unlikely to pose a problem.

Your SCC's limit of 30 amps though may or may not adequately utilize the panels rated wattage depending on your batteries voltage.

Be aware taht batteries wired in series could create a ballance problem.

 

[FlyingTeapot]

Your 4- 200 watt panels are rated in series to just under 90V but if you are in really cold weather you might get close to the 100v limit. I would install them as 2 in parallel and then series the 2 parallel banks. I assume you are using 12v here and paralleling the batteries. Put a 15 amp inline fuse on each series of panels and a dc rated breaker of 25 to 30 amp on the line coming into the charge controller. I would get a 100/50 instead as you will get more power. I have 800 watts on a 150/60 Victron and get sometimes 40 amps to the batteries. Not a big price difference.

Thanks Max! Confirmed 12v and parallel batts. I think I am going to go for the 100/50 controller for the throughput, and the peace of mind in colder conditions. What a great Forum, guys.

 

[Rocketman]

Actually the 100/50 will have the same “colder” limit as the 100/30 - the difference is it can produce 50amps of power instead of 30amps - so it can - if the sun is out and batteries are low - charge up the batteries faster.

By putting the panels is 2s2p - you will not have an issues with cold.
If you go 4s - all in series you “may”…
If you plan to go in series post the entire solar panel label - and let’s verify everything will be ok.

I went 2s2p with 200w panels into the Victron 100/50 and it has been working great!

 

[FlyingTeapot]

Actually the 100/50 will have the same “colder” limit as the 100/30 - the difference is it can produce 50amps of power instead of 30amps - so it can - if the sun is out and batteries are low - charge up the batteries faster.

By putting the panels is 2s2p - you will not have an issues with cold.
If you go 4s - all in series you “may”…
If you plan to go in series post the entire solar panel label - and let’s verify everything will be ok.

I went 2s2p with 200w panels into the Victron 100/50 and it has been working great!

GTK about the Amperage and Temp not having a correlation. I've ordered inline fuses for the 2s2p setup. The Hardtop over the Cockpit is going for Paint Monday, so I'll post pics of the install and labels then

 

[robbob2112]

If you do the 150/35 then you can go 4s and be good.