Speedster

Printed some brackets to attach to the wall

80g for the case and you need two of them.

I think you might be OK. The fans are loud and high pitched though. If they disturb then just try this. 
The input side is just the 3 holes with the 3 built-in fans. They blow into the unit. I didn’t want to interfere with their functionality. My thinking was rather put 5 fans over the much larger exit side and cause less restriction. 

The Sunsynk has passthrough up to 35A (i.e. 8kW). You could leave the 4kW element and should be okay, but if it was me I would switch out for a smaller element. Elements cost around R250. 
 
Water heating is linear, so halving the element size will double the required time which, in most circumstances, is not an issue. 

I don't think the batteries aren't working, but rather than ICC is displaying incorrect info.
 
 

I do believe the two inputs simply parallel on the board side. Is that's correct, then it makes no difference which one you use. 

Loading this competition today.
Jay

Panels also help during the day. 

This post and your previous post confuse me as they seem to contradict one another. Could you perhaps expand a bit?
 
Edit: oh wait, I see now you are talking about manufacturers seemingly incentivising consumers to buy a second battery. I think this view is disingenuous as it ignores the technical reasons for limiting discharge to 0.5C. 

Personal 2c, partly just trawling web pages, thinking out loud, stating the somewhat obvious, totally open to more informed views.
FreedomWon E-Tower 5000 appears to be a 1C battery only with restrictions, only for 5 minutes in a 30 min cycle or something like that, continuous discharge is lower at 4.2/3.6kW. Might be fine if you just want to cater for occasional surges when boiling the kettle, etc, but that might someday irk me because it's not a "true" 1C. Pricing around R32K mark, so seems a fair option. Warranty exclusions sound like a lot of excuses up front for why they may give you hassles later.
Greenrich completely new on offer, support in the market remains to be seen. 1.5C is great in theory, but no benefit over a 1C on a 5kW Sunsynk if you want a 5kWh. Scant information online, no global website, no international reputation, etc. Is this a rebrand? I'd be happy to test one for free, but for my own money I'd wait until there's more reputation and support built up.
Personally I've opted for the Weco 5K3, works well with Deye, I can assume for Sunsynk it'll be similar. Advertises 7000 cycles, so far so good, but a long way to go. Local service support from Weco is an open question, but it was sold by a reputable local dealer, and it is an established European brand. I see online pricing right now for R35K, so in a higher price class than 0.5C batteries. Needs a wall-mount bracket which is extra, or lay it on the floor and start a tower stack.
Hubble AM-2 - no personal experience with it, but on paper they only have warranty up to 3000 cycles, that caused me to opt against it, if you can get double the promised cycle life on a 1C battery for far less than double the price.
Hubble AM-5 - their new product, a 1C battery with 6000 cycles. If you can get one, I see they are advertised around R38,000 online. If I were buying again, and I had to buy one and only one battery, I would probably take this because of local presence for support on their older products, but understand that I'm taking a chance with their new battery on the market.
Sunsynk -  1C discharge rates but a 0.5C charge rate, 50A charge only. Not too bad, but the Sunsynk can charge 100A, so you'll have to set and keep it under its capability, possibly wasting a bit of solar generation in-between. But important to me, why is the lifespan not advertised prominently in terms of cycles? Sunsynk website simply says, lifespan is greater than 10 years at 25 deg C, if used in terms of the warranty restrictions. What does that mean, and why must I go and search deeper or read between lines to find out how often I can cycle the battery? That should be a standard advertised spec.
If budget allowed, best value for money would have been two 0.5C batteries up front, not the US2000C, but a 4.8kWh like the US5000, or otherwise the Dyness 4.8kWh which is wall-mountable so cuts out the need for a cabinet. The fact that it's 0.5C only matters with the first battery. Two batteries will deliver the max power the Sunsynk can output, and will last twice as long as a single 1C battery, generally at a lower price point, cheaper per kWh, with 6000 cycle life prominently stated. Restrictions TBC. Reputable international brands, probably with fair local support. But again, just thinking out loud, it's for you to check what's right and what works for you.

So GeyserWise have launched an IoT version of their display that can be paired with the tuya or SmartLife app. It's available in Centurion and I believe their Cape Town branch. I can't find it online yet. 
 
https://www.youtube.com/watch?v=O3Yk7HID7f4

The Sunsynk has passthrough up to 35A (i.e. 8kW). You could leave the 4kW element and should be okay, but if it was me I would switch out for a smaller element. Elements cost around R250. 
 
Water heating is linear, so halving the element size will double the required time which, in most circumstances, is not an issue. 

The Sunsynk has passthrough up to 35A (i.e. 8kW). You could leave the 4kW element and should be okay, but if it was me I would switch out for a smaller element. Elements cost around R250. 
 
Water heating is linear, so halving the element size will double the required time which, in most circumstances, is not an issue. 

Virtually all inverters will work as long as there is grid connected. It might not blend sources though - i.e. if draw exceeds available PV it'll switch over to grid only as opposed to one that blends which will only draw in the needed extra from grid.

You paid for the battery, you may as well use it (assuming you have solar). I'd cycle it each day. 

Hi @Speedster and @Scorp007
I replaced my 3kW element in my 150l geyser with a 2kW element to bring down my peak power usage.
Recently I replaced that with a 2kW PTC element, and it feels like the geyser reaches its designated temperature sooner. This feeling may be because I want to believe I invested well 
However, there are too many variables and without facts people can argue ongoing on this topic. I noticed that in this forum there are many debates regarding the PTC element efficiency.
As such I propose that this forum's users join me in an experiment. I suggest people that partake in this experiment:
Has a 150 liter stand-alone geyser Has a 2kW element in their geyser Has the ability to measure the duration/time of continued power applied to the geyser until the designated temperature has been reached The user has the ability to accurately and timely (relatively) measure the temperature of their geyser  Should you comply with above, please partake and share your findings?
I propose the following experiment, and this forum should please advise if we need additional constraints to ensure a better outcome.
Similar geyser set-up use of a 150 liter stand-alone electric and pressure geyser (no additional features e.g. evacuated tubes or flat plates) use of a 2 kW resistive heating element (PTC or not) assume geysers are in the roof We will run the experiment at night then the roof insulation is assumed having little effect some PTC elements has a DC feed to the element as well, and this will negate such an impact The geyser may not be used at least 30 minutes prior to the experiment nor during the experiment E.g. no tap used on that geyser We will start the experiment with a geyser temperature within a given range (e.g. between 25 and 35 degrees), as close to 30 degrees as possible However, the element may not be activated/powered at least 30 minute prior to the experiment We then measure:
Confirm compliance with the constraints Confirm the date and time of the experiment Measure the outside temperature Confirm the Geyser Temperature Temperature and time of starting the experiment Temperature and time of reaching 10 degrees higher than the starting temperature (we note temperature because the measuring mechanism may have a delay and be a fraction out from 10 degrees) If I can have head's up on this, I am willing to go first and other participants can use that as a template allowing us to compare our findings?
 
Yours faithfully
Pieter

You paid for the battery, you may as well use it (assuming you have solar). I'd cycle it each day. 

1) Yes that will help.
2) you can simply use a standard 2 kW element. I don't get the big push for expensive PTC elements 

1) Yes that will help.
2) you can simply use a standard 2 kW element. I don't get the big push for expensive PTC elements 

1) Yes that will help.
2) you can simply use a standard 2 kW element. I don't get the big push for expensive PTC elements 

1) Yes that will help.
2) you can simply use a standard 2 kW element. I don't get the big push for expensive PTC elements 

I'm guessing the installer needs to take responsibility to get this sorted?

I'd rather hook it up to the Aux port.

Please see below pic

There should be a cable connected from the CAN port of the inverter to the battery CAN port. On home screen, tapping on the battery icon and then Li-BMS bottom right should give you the communication status