Hi all, I’ve been lurking around these forums for quite a while now and finally got my installation done earlier this week.

- Deye 5kw Inverter

- 2 x 5kwh Freedomwon E-Tower

- 8 x 460w panels (3.68kw)

all circuits on essential except geyser.

Before this installation, the 2 person household used  an average 17kwh per day. We have a gas stove, solar geyser and a 1.1kw pool pump and led lights throughout the house. After installation and with careful sequencing of activities and sheer power dictatorship we have managed to keep Eskom use below 3kwh per day.

The daily routine is as follows.

Battery is usually 50%/60% SOC by 5am, I then fire up the geyser for an hour (4kw element 😭) via the geyserwise controller to heat up water  for the 2 morning showers, I have set the battery minimum SOC to 35%. The battery does the heavy lifting and Eskom contributes about 1 - 1.5kwh. This usually takes the water from 30 degrees to about 48 degrees.

Between sunrise and 12h00 the following takes place

- pool pump runs for 1 hr

- batteries charge up to 100% soc

- occasionally  1 load of laundry gets done

Between 12h00 and Sunset, the following takes place:

- Boost the solar geyser for an hour (12h30 - 13h30), battery drain set to 85% SOC. On a good day Solar and battery do most of the work but Eskom occasionally contribute 1kwh in the last 15mins

- Charge batteries up to 100% again

- Run pool pump for another hour from 14h00 - 15h00, purely off solar (battery SOC min of 100%  set from 14h00 to 17h00)

Question is Does my power management routine and these geyser runs harm my batteries in anyway ? Does the midday geyser run off the batteries count as a cycle ?

Side note: I’m looking into a heat pump to ease the power draw and will consider a smaller element in the meantime. Also heading into the first cloudy weekend so will need to make sacrifices here

Edited May 27, 20233 yr by King_M

3 hours ago, King_M said:

Question is Does my power management routine and these geyser runs harm my batteries in anyway ? Does the midday geyser run off the batteries count as a cycle?

This is an extract from the FW warrenty clause:

"Each Freedom Lite battery is preconfigured to prevent ordinary discharge below 90% DoD. 100% DoD is 
allowed when the discharge from 90% to 100% DoD is only for the purposes of supplying the standby power 
draw to the inverter when there is no AC input. It is the responsibility of the installer or designer to ensure that 
the battery and solar capacities are adequate to achieve an average daily DoD of 80% or less or to ensure that 
the inverter reverts to grid consumption at or above 80% DoD (for grid connected systems). The additional 
margin (from 80% to 90% DoD) is only intended to be used for abnormal circumstances such as grid outages 
for grid connected systems and for cloudy weather or above expected demand on off grid systems. The Lite/Tower 
should not spend more than 20% of its warranty life (equivalent to 2 years) below 20% SoC to maintain the 
warranty. This parameter is recorded by the BMS. "

FW cycle count: 

"The integrated battery management system (BMS) is capable of calculating and recording the aggregate 
number of cycles that have been completed by the battery where one complete cycle in terms of this warranty 
is a discharge from 100% State of Charge (SoC) to 20% SoC – which is equivalent to 80% Depth of Discharge

24 minutes ago, TaliaB said:

FW cycle count: 

"The integrated battery management system (BMS) is capable of calculating and recording the aggregate 
number of cycles that have been completed by the battery where one complete cycle in terms of this warranty 
is a discharge from 100% State of Charge (SoC) to 20% SoC – which is equivalent to 80% Depth of Discharge

So because I only drain my batteries to 35% does it mean that I’m not cycling the batteries at all? Is this a good or a bad thing ?

36 minutes ago, King_M said:

So because I only drain my batteries to 35% does it mean that I’m not cycling the batteries at all? Is this a good or a bad thing ?

Your statement is a bit confusing. Do you only use 35% of your battery capacity before charging? If your are discharging to 75% soc and charging again there is nothing wrong with that actually your batteries will last longer than discharging to 20% soc every time as that equates to 1 cycle. If you are discharging to 35% soc then it is almost 1 cycle.

Edited May 27, 20233 yr by TaliaB

6 minutes ago, TaliaB said:

Your statement is a bit confusing. Do you only use 35% of your battery capacity before charging? If your are discharging to 75% soc and charging again there is nothing wrong with that actually your batteries will last longer than discharging to 20% soc every time as that equates to 1 cycle.

in the morning, I discharge to 35% SOC to heat up the geyser, then let the batteries charge up to 100% during the rest of the morning

in the afternoon I discharge again but this time to 85% SOC to boost the geyser for the evening showers. The battery then charged up to 100% again in preparation for running the house through the night

 

 

 

Edited May 27, 20233 yr by King_M

5 hours ago, King_M said:

Battery is usually 50%/60% SOC by 5am, I then fire up the geyser for an hour (4kw element 😭) via the geyserwise controller to heat up water  for the 2 morning showers, I have set the battery minimum SOC to 35%. The battery does the heavy lifting and Eskom contributes about 1 - 1.5kwh. This usually takes the water from 30 degrees to about 48 degrees.

I don't want to comment on the inverter settings because I have a different inverter with a different way of working. 

I am surprised to see the performance you cite. I do better each morning for less power. But I have a heatpump, and I have lots of insulation on the geyser and hot water pipes.

The geyser especially has a "blanket" about an inch thick. 

A heat pump won't be small change, but maybe you want to look at the insulation aspect. 

Well done on having this plan you run to. I need something like that. It's better than just turning stuff on and hoping for the best. We are sort of half way there, but we still get close to an overload sometimes. 

Very nice setup and minimal Eskom usage! I'm looking at a similar setup with similar usage, with an 8kw instead of 5kw for some headroom and future proof, with geyser on essential with timer.

Do you feel the 5kw limits you? With geyser on non-essential, does loadshedding make you miss some good PV days to power it up? Is most of the remaining 3kwh usage for the geyser? I've read water should be heated to 60C once a day, do you achieve that?

Thanks

 

2 hours ago, solazzz said:

Very nice setup and minimal Eskom usage! I'm looking at a similar setup with similar usage, with an 8kw instead of 5kw for some headroom and future proof, with geyser on essential with timer.

Do you feel the 5kw limits you? With geyser on non-essential, does loadshedding make you miss some good PV days to power it up? Is most of the remaining 3kwh usage for the geyser? I've read water should be heated to 60C once a day, do you achieve that?

Thanks

 

I find that the 5kw is actually plenty sufficient for my needs, I don’t think I’ve ever come anywhere close to the 7kw max passthrough capacity . I do however wish I had added 4 more panels to get batteries full quicker and also help out on those cloudy days. 

Since I’ve got a solar geyser, even with load shedding, the PV collector still heats up the water so I’ll still have decent 50C water (in winter) for the evening showers. I now fire it up to 70C purely on batteries and PV, this now leaves me with enough hot water for the 2 evening showers and 2 morning showers without having to fire up the geyser again in the morning. Will see how effective this will be as we head deeper into winter. I’m not happy with over night temp loses on the geyser (over 15C on some nights).

I now average about 2kwh a day, and most of this is from the geyser run at midday (once 85% SOC is reached on the batteries - Eskom jumps is a little bit, I could possibly drop SOC setting to 75%, but I would likely not go into the night with full batteries if I did this or I’d have to sacrifice pool pump time). I imagine that in the summer months, I won’t need Eskom at all on most days,  except rainy days.

On average with this setup, by 16h30,  I’ve got my 2 batteries at 100%, a 200L geyser with > 70C water, a clean pool and often with a dishwasher / laundry load done. My house then runs fully on batteries over night.

Once I get a heat pump in the mix (a 3.6kw ITS  heat pump pulls about 800w), I’ll have plenty of capacity to run without so much sequencing and monitoring and will move the geyser to essential.

for now, I’m looking to get into Home Assistant to use some “intelligence” to run automation on the geyser and pool pump taking into account PV, weather forecasts, SOC  and that sort of thing.

For my current needs, If I had R45k to spend, and had to choose between a 5kw and 8kw, I’d take the 5kw and fund a heat pump with the difference, should headroom become a concern later, I’d then add another 5kw which also gives some redundancy should an inverter fall apart.

sorry for essay 😂

I am now totally off grid since April 2022. Geyser was the first to be taken off grid - kept my electric geyser and added heat collector panel with circulation pump. Only in winter do I need to trun on my geyser and run it via the inverter. I would recommend you get an additional heat source for your geyser.

I also have a 20kWh Freedom won battery but I only drain it to around 50%. They say if I use it like this most of the time it could last 16+ years. If you drain yours down to 35% every night they will still honour the 10 year warranty.

I did notice one thing about the battery though: After a few cloudy day the BMS might report a decent charge, say 80% - 90% BUT the battery voltage is sometimes at about 52V (operating voltage for Freedom won batteries is about 51V - 53V). This voltage might look good until you switch on the microwave or kettle when there is no sun, like in the evening. Then the voltage very quickly will fall to 48V. This 48V is the absolute minimum for the Freedom won batteries and equates to about 90% DoD. Below 48V the battery performance becomes VERY unpredictable. On my Kodak (Axpert King) inverter I cannot set the minimum voltage for the inverter to switch off as this is handled between the BMS and inverter. However, I saw that the BMS setting for cut off voltage (called Minimum Pack Voltage on the Orion BMS) was set to 46V. Being off grid, once the battery reaches 46V, everything will switch off and my whole installation is basically dead in the water. So this 46V is a wrong setting and Freedom won did not even know about this. I logged a call and they managed to change the setting but could only up it to 48V - BMS won't pass a higher setting to the inverter than 48V, even if they set it to a higher value on the BMS. But 48V works for me because my inverter wil switch off before the battery circuit breaker trips.