Steve87

Energy storage is just potential energy. You won't exceed anything on the inverter. It's like hooking up batteries in parallel to your motor car, you car would still just use what it needs from the battery. The inverter is the same, you are adding potential energy that can be used by the inverter whenever it needs it. Maybe another simple explanation is fuel inside your cars fuel tank. You can add an extra external fuel tank & that means you car can travel further but it won't damage the engine in any way.

Keep us posted, there are quite few guys battery building & some guys that will add some great value. The first time you connect the battery & it produces power, that rewarding feeling is what is addictive.

So you need to decide whether you subscribe to compression or not. Me personally I don't subscribe to it. I can't convince you, it's a personal choice, do the research & do what is comfortable for you. Setup the cells in a long parallel stack using the busbars, set your charger to 3.60V & set 10A. Some guys go as high as 3.65V personally I don't think it's necessary, 3.6V is as good as it gets for me. When the charger reaches 0A you know your cells are all top balanced. Now you can begin your battery assembly starting with good knowledge that they are all at the same SOC. Now 10A over a stacked Parallel set of 15 or 16 cells can take a long time to charge. Because that's 100ah x 16 or 15 cells so you might need to let this charge a good few days depending on the individual SoCs. Also make sure you place you charger + & - on opposite ends of the parallel stack, so that energy is traveling directly through the entire bank, not via individual cell transfer. Your 10A charger can take long & that is why I prefer the 40A charger it just goes 4 times faster & can also give me cycle data on the cell, but what you have there will definitely be good enough to do the job. Enjoy the build if it's your first time: be careful it's becomes addictive !!

This is the variable up to 5V & 40A charger. I don't know of other ways maybe some other guys can step in & comment but I don't know another way to top balance without this equipment.

Ideally you need a DC variable power supply. I have 2 different chargers. One is variable voltage up to 5V but high amperage & one that is variable to 60V at low amps 5amps. Just placing them in parallel without a charge will not do anything.

I would definitely go the full way & Top balance, the voltage tells you absolutely nothing about the SoC of each cell. Will also save you a lot of hassles because it will be your Quality control that when you assemble your pack you know they all started at the same SoC...

I would look to add a Transformer based Inverter for this application. I have worked in the C&I market & have seen on one particular site with a very large walk in Cold room that compressor generate high surge cold start currents. The Gate & Drive Sunsynks & Deyes have their place in the market & that's usually when there is no heavy inductive loads, however, when you start playing with factory or industrial equipment like compressors & motors the application needs to be specified accordingly. Otherwise you run the risk of your solution not working. I would recommend equipment like the ATESS HPS range or Megarevo MPS range depending on your power requirement. They are High Voltage machines & are built for industrial applications with in built isolation transformers. However, I would first start with a power investigation with a Logger or meter to find out your power peaks & requirements followed by matching the inverter output current to at the very least to match your Grid input breaker. These projects often cost a lot of money, so due diligence must be followed with planning, selection of equipment, installation execution as well as plant management (operations & maintenance).

This is what separates the Cowboys from the real proper operators...

No need to upgrade your inverter. Energy storage is not dependent on the Inverter to handle that storage. Eg. You can have a 5kW Inverter that has 100kWh of battery storage, the only question comes when designing such a system is how will you charge such a huge battery bank. In your case depends how many panels are attached to make it renewable from the Sun or will you accept Grid Charging as an option??? So simple answer no. Don't need to upgrade your inverter. But that depends on your charging & load requirements to fill up this larger battery.

What application are you looking to deploy this plant in? Commercial? Residential? What is your requirement?

Hi Mike, This is purely through observation of my own solar lab setup & from paralleling FreedomWons of different capacities: The only thing the BMS is sending the inverters is % SoC, CCL, DCL & alarms. Besides that the Sunsynk & for that matter any other inverter doesn't make heads or tails of anything else. Ok in the ATESS it also shares the Max & Min cell voltage & temps. But you can setup anything on Comms in the chain & then DC couple more on the same DC bus & as long as you can verify the batteries are working well & on & moving together there won't be any problems at all. I have paired 2 x 10/8s with 2 x 15/12s to this day they all working well with their respective master & slaves & keep the same SoC values. This is paired with 2 x Deye 12kW machines...Been in operation for close to 15 months without issue.

The main reason Freedom Won have issues with the E-Tower is that it's a rebadged & assembled in China product. They don't have nearly as many issue with their Lite range for Residential and commercial use because they are locally assembled & the QC is much higher. One thing I will say is that in either event when there is an issue they stand up & take responsibility. I have seen issues with their lite range as well & they have never ignored the issues. I don't have issue dealing with them, when the need has arisen.

On this Volta BMS issue, the BMS tells the inverter it wants to charge to 56.8V & if this is a 16s battery that's a bit too high in my opinion. Because 56.8V ÷ 16 cells = 3.55V. That assumes that all cells are very well balanced. Remember these cells can only get to 3.65V without some issues and above 3.45V per cell the cells start to show the imbalance because we at the top end of the charge curve. So again I don't know how configurable these Volta BMSs are but if it's stuck pushing it's way up to 56.8V I'm afraid that problem will persist. I don't know the Volta BMS cell balancing strategy but if it's passive that battery will not be useable with those battery Comms without some hardware intervention. Last resort take it to the supplier...To make the battery useful to get power from it revert to No Comms, charge bulk to 54V & Float at 54V. Cut off at 48V. That will keep the battery working & keep the cells & BMS happy. However, you will no clue what's the SoC unless these is a small bar indicator. Never been exposed to Volta so forgive my ignorance.

The reason I mentioned the above post is because the E-Tower is a pace BMS based Battery. It's definitely not an Orion BMS like the Lite version of the FW battery. I think this may be the cause of the issue. The SVolt has the same Pace BMS, however, the pace is highly configurable so it can be setup to operate as a Pylontech protocol or as anything else as required. However, I would not think that it will share the same details as the FreedomWon Lite range & the Solis Battery options for FW Lite as installed in the firmware, I don't think covers both protocols but I could be wrong. Unfortunately I have never paired an E-Tower with a Solis yet. So unfortunately this is a rabbit hole of sorts.

@P1000 has the answer, but to confirm this you need to get connected via a laptop to confirm that the issue lies on the battery side. In any event the BMS is asking the inverter to make charger decisions, the inverter is obliged to follow what is requested. Once the Inverter let's say charges to say 55V for eg. Then the BMS can complain if a cell reaches an overvoltage condition. So if you are sure you have established Comms positively, then this above scenario could very well be the case. But remember as well that this is an E-Tower & the Comms protocols are not the same as he FW Lite batteries. I have commissioned a site that used a SVolt battery & it worked using Pylontech as it's battery Comms protocol with the S6. So keep this in mind.