MPPT Charge controller

[Tillers]

Hi all, I don't know if I'm in the right place but hoping so. I'll be putting 600w of solar on my boat and need a charge controller. I was wondering if anyone may know if 50 amp charge controller will be enough? I was thinking of a Victron MPPT 100/50 (12/24v) – 50A The power will go to three 140amp leisure batteries.

Many thanks

[inetdog]

Hi all, I don't know if I'm in the right place but hoping so. I'll be putting 600w of solar on my boat and need a charge controller. I was wondering if anyone may know if 50 amp charge controller will be enough? I was thinking of a Victron MPPT 100/50 (12/24v) – 50A The power will go to three 140amp leisure batteries.

Many thanks

You don't say it explicitly, but from the three batteries we can assume that you have a 12V nominal system.
With a 100% efficient MPPT CC your 600W of panel could produce a maximum current of 50A at 12V. So, yes a 50A CC is large enough by that standard.

Looking at it from another direction, 3 X 140AH is 420AH, and by rule of thumb for FLA batteries you would need 420W or more of panel to be able to charge that battery bank properly. You have that too.

However, putting three 12V batteries in parallel is not the best way to get the storage capacity you need. Look at what is available in 6V batteries instead. You should be able to find a single 6V battery with over 200AH of capacity, so two of those in series would be far preferable to three in parallel.
Or you could go to a 24V system, which would allow your 50A CC to handle up to 1200W of panel in the future.

[Tillers]

You don't say it explicitly, but from the three batteries we can assume that you have a 12V nominal system.
With a 100% efficient MPPT CC your 600W of panel could produce a maximum current of 25A at 12V. So, yes a 50A CC is large enough by that standard.

Looking at it from another direction, 3 X 140AH is 420AH, and by rule of thumb for FLA batteries you would need 420W or more of panel to be able to charge that battery bank properly. You have that too.

However, putting three 12V batteries in parallel is not the best way to get the storage capacity you need. Look at what is available in 6V batteries instead. You should be able to find a single 6V battery with over 200AH of capacity, so two of those in series would be far preferable to three in parallel.
Or you could go to a 24V system, which would allow your 50A CC to handle up to 1200W of panel in the future.

Hi inetdog, sorry I haven't made myself very clear. It's for a narrowboat which has a 12v system when out from the shoreline power. So TV, lights etc are 12v run. It does have an inverter which transforms to 230v. Please excuse my ignorance, but would 24v not be compatible?

[inetdog]

Hi inetdog, sorry I haven't made myself very clear. It's for a narrowboat which has a 12v system when out from the shoreline power. So TV, lights etc are 12v run. It does have an inverter which transforms to 230v. Please excuse my ignorance, but would 24v not be compatible?

If you have a significant 12V DC load, the only practical way to run them from a 24V battery bank would be to put in a DC to DC converter for that purpose.
You would probably have to replace the 230V AC inverter two unless it can handle two input voltages.

You should take a close look at the general purpose and specifically boat related technical information at http://smartgauge.co.uk/batt_con.html for a start and all of the rest of the Tech Tip pages as you have time.

[Tillers]

If you have a significant 12V DC load, the only practical way to run them from a 24V battery bank would be to put in a DC to DC converter for that purpose.
You would probably have to replace the 230V AC inverter two unless it can handle two input voltages.

You should take a close look at the general purpose and specifically boat related technical information at http://smartgauge.co.uk/batt_con.html for a start and all of the rest of the Tech Tip pages as you have time.

Looks an interesting site. I'll be taking a peek later. Thank you. I won't go down the 24v route as I think it'll complicate matters and the inverter is a 3000 k system. Could look at the 6v though.
I'm going to try and go for an 80 amp MPPT but the price are so high. But that way if I do at a later date wish to add another panel or two, It'll allow me to do so

[Sunking]

You don't say it explicitly, but from the three batteries we can assume that you have a 12V nominal system.
With a 100% efficient MPPT CC your 600W of panel could produce a maximum current of 25A at 12V.

What am I missing Dave? My protein computer, all two cells left, say 600 watts / 12 volts = 50 amps.

[inetdog]

What am I missing Dave? My protein computer, all two cells left, say 600 watts / 12 volts = 50 amps.

I started out writing 300W instead of 600W and I fixed that but I did not correct the A figure. Not having a good day.

[SunEagle]

I started out writing 300W instead of 600W and I fixed that but I did not correct the A figure. Not having a good day.

It happens to all of us.