Battery Charging

[Dante3117]

I have a large battery bank - 56 -100Ah batteries in 14 strings of 4 giving me 48V and 1400Ah. My question is: Can I have multiple MPPT charges connected to the same bank and do they have to talk to each other or will a MPPT know what the others are doing? I currently have a single EPEVER Tracer 10415AN MPPT charger which can technically yield 100A but in reality is not which is probably due to the time of year. The issue with the single charger is that it doesn't fully charge during the day which leaves a partial charge for the next day.

I would like to add another charger but don't know if the two will conflict. I was told they would not but I thought I would ask the experts in this forum. PS I have excess solar panels so adding another charger is not a big deal cost wise.

Thank you for your input.

[SunEagle]

This may not be what you want to hear but I am more concerned with how those 14 strings are going to evenly charged and discharged. I think you have a bigger problem with how the batteries are wired then how they can be charged using multiple CC.

If money is no problem then I would look into batteries that have a high Ah rating and low voltage so I can wire them in series instead of in parallel.

[Dante3117]

All the strings have exactly the same gauge and length wires going back to a + and - buss bars. Within each string the interconnected wires are exactly the same length and gauge. All wires have terminals that are exactly the same hardware and lugs. I see your concern and followed battery wiring directions to the letter to avoid what you are describing might happen.

The inverter and MPPT chargers are connected to the buss bars.

[SunEagle]

All the strings have exactly the same gauge and length wires going back to a + and - buss bars. Within each string the interconnected wires are exactly the same length and gauge. All wires have terminals that are exactly the same hardware and lugs. I see your concern and followed battery wiring directions to the letter to avoid what you are describing might happen.

The inverter and MPPT chargers are connected to the buss bars.

I understand you took extra caution in your wiring. But I can also tell you that no matter how "exact" the wiring is for each "string" there are still some resistance differences. That can be either in the wiring or termination but the strings with a lower resistance will take the lead in discharging and charging so they will cycle a lot more and fail first. The odds and chances of failure go up and against you when you increase the number of strings.

[JackInQuebec]

I'm newbie, first post I have the same questions and it was not answered here, on 12V now but later on moving to 24V, have 4 Rolls AGM for 830Ah, in addition to the 30A MPPT charger, could I charge the batterries with another external 30A AGM charger? What's the science for charging batteries?

What if I add a wind powered generator?

I know I need to beef up the solar panel setup (on todo), need to buy a bigger MPPT (on todo).

Thanks!

[SunEagle]

I'm newbie, first post I have the same questions and it was not answered here, on 12V now but later on moving to 24V, have 4 Rolls AGM for 830Ah, in addition to the 30A MPPT charger, could I charge the batterries with another external 30A AGM charger? What's the science for charging batteries?

What if I add a wind powered generator?

I know I need to beef up the solar panel setup (on todo), need to buy a bigger MPPT (on todo).

Thanks!

I believe you can have multiple chargers connected to the same battery bank but from what I have heard they need to be the same and better yet "talk" to each other so one does not try to take control and over charge the system.

IMO having a single CC rated for the output amps to keep the batteries happy would be the best way to go. With a 830Ah system you would need an 80 amp MPPT CC and the associated panel wattage to get that 80amps.

I have yet to hear about a wind turbine and solar CC connected to the same battery bank but then again hardware is improving and you might be able to do that.

[Mike90250]

Rather than feed you a bunch of stuff, here's a trusted source for battery info - ignore the peanut gallery comments after each article

https://batteryuniversity.com/learn/article/lead_based_batteries

Generally, well matched & configured chargers can be connected in parallel to a single battery bank . I can use 4 charging sources,