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Steve_S is correct. LifePo4 cells have a higher thermal and chemical stability than lithium-Ion cells. I’ve seen plenty of LiPo fires and simply puncturing a cell will cause thermal runaway resulting in a fire. Over charging takes longer and much incompetence to result in a fire, but it does...

I agree with Craig, balancing of cells can be achieved at varying charge states with active balancing or balance charging. Balance charging is crucial for certain cells such as LiPo batteries for example. If LiPo batteries are to be stored for any duration they must be balance storage charged...

I also have a cabin/cottage in northern Ontario. Where are you located approximately? 5 sun hours per day seems high. It might be a good idea to use worst case value of sun hours or December/January values.

Float charge shouldn’t damage a lead acid battery. Here is some info: https://batteryuniversity.com/learn/archive/can_the_lead_acid_battery_compete_in_modern_times

I have a question pertaining to the calculation of the temperature correction based on the given temperature coefficient for VOC referenced in the above quote. In lieu of the values described in the above quote, shouldn’t the calculation be as follows? Given: - VOC = 116V - Temperature...

Yes, I’m running a 3/4hp electric water pump, but my Honda 2000w generator was able to run a 1000w microwave and the water pump at the same time without fault. So, applying days of autonomy to the array must be where I was getting confused. If days of autonomy are applied to the size of the PV...

Wow! Thanks for all the info, much appreciated. I agree, the overly optimistic value they list for the daily power generation must be based on higher sun hours per day. For my location I should get approximately 2.4 hours per day of sun in December and 4.5 in June. I’ll definitely research...

Is anyone on this site familiar with the pre-wired FlexPower one systems by Outback? Outback offers the following systems in both 24v and 48v. FP1 FXR2524A (2.5kw 24v) FP1 VFXR3524A (3.5kw 24v) FP1 FXR3048A (3kw 48v) FP1 VFXR3648A (3.6kw 48v) All of the pre-wired systems come with the FM80...

The issue may be due to the Magnum remote and BMK not having the ability to communicate with the battery BMS in a closed loop system. Currently Magnum does not have the ability to connect the BMK firmware with the Lifepo4 BMS, so there is no commumication, which results in a open loop...

It's always a good idea to have a backup power source. If you design your solar system to account for a few days of autonomy and if the system has a power service factor (overkill) and accounts for efficiency losses you can minimize the use of a backup generator.

Yes, I understand and I agree, but the weak link is still the FM80 and the system should be designed to the weak link and advertised accordingly. It would be a big mistake if one were to design their PV array and battery size based on the advertised power of this system 3.5kw. When designing...

I’ll heed your advice and run 3 panels in series. I’ll start with 3s2p and upgrade to 3s3p if needed. Now back to the panel cell count. I just want to wrap my head around this so I understand. A 120 half cell panel contains 2 parallel strings of 60 half cells in series. If each cell has a Voc...

snoobler and Hedges, thank you! I checked the sun hours and and the closest city listed for Ontario Canada is located 0.2° latitude further north and about 400 miles west of my location. The value for that location, panel orientation and tilt = 2.8 average sun hours per day. So, the 2.5 I used...

snoobler, I’m not saying I’m mad, sorry if you miss understood the intent of my post. The intent of the post was to get an explantation as to why a 3500w pre-wired system is limited to a 2000w solar array. “You still lack a basic understanding of these concepts and still see a problem. Even if...

I'm a little confused. The FM80 is rated for 80A, 150V max. Please let me know what I'm missing. 3S2P panel configuration (VOC) 39.9V x 3 = 119.7V x 1.25 (temp adjustment) = 149.6V (IMPP) 9.52A x 2 = 19.04A 2S3P panel configuration (VOC) 39.9V x 2 = 79.8V x 1.25 (temp adjustment) = 99.75V...

Hi all, I’m looking forward to sponging some knowledge from y’all. I’m currently located in Southern Ontario and I’m building an off grid cabin in Northern Ontario. I’ll be designing a solar system over the winter. I’m looking at between a 2.5 to 4kw system. Anyways, thanks for having me and...

Thanks snoobler! I guess I’m accustomed to solar system sizes being listed as the PV rating and not inverter output rating. Yes I’ve read that brochure and have researched all online info I could find on these systems. Given: I ran a watt hour meter on my generator powering my cabin for two...

Ok, because I was planning on starting with 2S3P and adding one string at a time in the future until my limit is reached or the system is balanced. This will allow me to purchase 2 panels at a time as opposed to 3 panels. Assuming a 48v system, FM80 max array = 4000w. Starting configuration...

Thanks Steve_S. My property is located near Hearst, Ont. I too will be completely off grid with the water being pulled from a river running through the property. I’ve been looking at this setup, but I’m not sure if the Magnum systems will work with lifepo4 batteries...

My cabin is located in Northern Ontario Canada, which has an average high temperature in July of 74°F (24°C) and may reach slightly above 30°C for a few days in July. So, if I use 55°C panel temp or 30°C above ambient it would yield 66.2V-(0.116x30°C) = 62.72V

SolarQueen, thank you for your input. Much appreciated, especially for a beginner like myself. These panels are 120 cell panels.

I didn’t know that, thanks. So should I be halving the listed Voc and Vmp when used in my calculations?

Very helpful, thank you. My logic behind running more parallel strings is to reduce the negative affects of shading along with purchasing 2 in lieu of 3 panels for future upgrades. If it’s more efficient for the system to run 3 in series I’ll do it and just suck-up the additional cost of the...