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Battery compatibility with Axpert/Voltex MKS 5KVA

Featured Replies

Good day,

I currently have an inverter/battery setup as per the pictures. Bought the house with it pre-installed. 

8 x Deltec 12v High Cycle Lead Acid batteries
1 x 5kw Voltex MKS 5KVA inverter (Axpert rebrand it seems).

Only the 'essential load' in my house is connected to this system. No stoves, AC's, geysers, etc. 

I want to replace the batteries (which are as good as dead) with a lithium battery, preferably around 5kw, that's compatible and has a decent warranty/cycle life. When the batteries were still good, it would easily last  5+ hours. Now it only lasts about 20 minutes. 

Questions:
1. Which batteries will work with this inverter?
2. Any recommended suppliers in the Cape Town area? Prefer someone that can come and install and PROPERLY configure the inverter so the battery is charged/discharged correctly.

 

inverter_2.jpeg

inverter_3.jpeg

inverter.jpeg

Have you tested the batteries? It's possible that only one battery (or one cell for that matter) could be at fault. But it's not advisable to replace only one battery in a bank.

Pylontech, Hubble, Bluenova and FreedomWon is compatible with the Axperts as far as I know. There might be more. The market is flooded with Lithium batteries these days.

 

  • Author
3 minutes ago, Czauto said:

Have you tested the batteries? It's possible that only one battery (or one cell for that matter) could be at fault. But it's not advisable to replace only one battery in a bank.

Pylontech, Hubble, Bluenova and FreedomWon is compatible with the Axperts as far as I know. There might be more. The market is flooded with Lithium batteries these days.

 

Yeah I did the check. 2 of the 8 are sitting at around 7-9v. Some others around 10 to 11v. only 4 of them measured above 12v. So I disconnected the 4 worst ones and only kept those 4 installed. I still managed only about 15-20 minutes of power. 
I've had someone out here as well and they said it's not worth trying to revive the batteries as they're over 4 years old and have been abused with load shedding in that time. And I agree, with this load shedding these things charge/discharge 2 times a day so it's not ideal. 

Lithium has to be the way to go here. 

More information on the inverter can be found here:
https://www.voltex.co.za/axpert-mks-3k-and-5k/ 

 

1 hour ago, h3t said:

8 x Deltec 12v High Cycle Lead Acid batteries
1 x 5kw Voltex MKS 5KVA inverter

It looks like your existing batteries are 2x 100Ah. Therefor I recommend at least 200Ah 48V LiFePh batteries, that would be 9.6kWh. Standard packs are 100Ah, put at least two such in parallel. The more batterie capacity the better, in particular with the actual Escom perspective.

Edited by Beat

  • Author
1 minute ago, Beat said:

It looks like your existing batteries are 2x 100Ah. Therefor I recommend at least 200Ah 48V LiFePh batteries, that would be 9.6kWh. Standard packs are 100Ah, put at least two such in parallel.

That's true, but the DoD on a lead acid is way higher (above 50%) compared to a lithium which should comfortably go down to 20%. 

12 hours ago, h3t said:

Which batteries will work with this inverter?

Most lithium batteries will work with your inverter, you just won't have direct comms between the battery and inverter, you will have to set it to USE mode and set the voltages manually. If you want bms comms then you will need something like solar assistant between the two.

If you do get a single 100Ah battery just make sure it can do at least 1C discharge or you won't get 5KVA from your inverter.

  • 2 weeks later...
  • Author

Thanks to everyone that responded to this.

In short - the inverter is more than happy with a lithium battery if you use the 'USR' profile and set it up to manufacturer's recommendations.

I eventually bought a Hubble AM-2 with a Hubble CloudLink from https://powerprovider.co.za/. The shipping cost R200 and it was delivered to me, in Durbanville, in 3 working days . It's a relatively straightforward installation and so far it's working wonderfully!
I used the USR profile on the inverter and set up the values as per Hubble's own recommendations (they were very helpful in this regard and assured me beforehand that it would work fine). Only thing I did differently is to set the cut-off voltage to 45V and not 44V to prevent it discharging too much, although it seems I'm rarely going to get that low 😃

Below is the battery + inverter graphs. I only have essential loads on the inverter (plugs + lights basically). Even with 4 hour load shedding slots I'm barely touching 70% SOC. 
image.thumb.png.6dae557adf3a0ca62ea6b7f00a17879c.png


image.thumb.png.9faadaaeb1c20933fb1fc5d30be2c422.png

  • 3 months later...

Hi there, I have the exact setup as you i.e. voltex inverter and looking to replace 4 x 12v lead acid batteries with lithium. Out of interest how is the hubble AM-2 going? Did you swap out the battery yourself of get an installer to do this? Many thanks

On 2023/02/23 at 9:49 AM, h3t said:

Thanks to everyone that responded to this.

In short - the inverter is more than happy with a lithium battery if you use the 'USR' profile and set it up to manufacturer's recommendations.

I eventually bought a Hubble AM-2 with a Hubble CloudLink from https://powerprovider.co.za/. The shipping cost R200 and it was delivered to me, in Durbanville, in 3 working days . It's a relatively straightforward installation and so far it's working wonderfully!
I used the USR profile on the inverter and set up the values as per Hubble's own recommendations (they were very helpful in this regard and assured me beforehand that it would work fine). Only thing I did differently is to set the cut-off voltage to 45V and not 44V to prevent it discharging too much, although it seems I'm rarely going to get that low 😃

Below is the battery + inverter graphs. I only have essential loads on the inverter (plugs + lights basically). Even with 4 hour load shedding slots I'm barely touching 70% SOC. 
image.thumb.png.6dae557adf3a0ca62ea6b7f00a17879c.png


image.thumb.png.9faadaaeb1c20933fb1fc5d30be2c422.png

Sorry my previous post is in response to this update to be clear! 

  • Author

@DP1
I'm VERY happy with the outcome so far. I only notice load shedding on my heavy-load appliances (stove, geyser, and pool pump) these days. I'm yet to go below 60% SOC on the single battery. Now I wish I could do solar on this setup as well but the City of CT doesn't approve of the inverter 😢

@h3t

Excellent, thanks for the feedback I think I will go the same route! 

Re the City not approving of the inverter, is this for feeding back to the grid/compensation? I would imagine one could continue with the solar setup in any case and forfeit this benefit?

Would you recommend the guys that did the installation of your battery? If so, could you kindly forward me their details?

 

Many thanks!

  • Author
3 minutes ago, DP1 said:

@h3t

Excellent, thanks for the feedback I think I will go the same route! 

Re the City not approving of the inverter, is this for feeding back to the grid/compensation? I would imagine one could continue with the solar setup in any case and forfeit this benefit?

Would you recommend the guys that did the installation of your battery? If so, could you kindly forward me their details?

 

Many thanks!

As mentioned previously, did it all myself. Not that hard, but obviously to get a COC I'll need to get someone in to sign-off. I have some other electrical work that needs doing around the house so I'll ask that electrician to sign off for COC. 

Re the 'approved inverter list'..not really too interested in the compensation plan (yet) but in order to generate electricity on your property while still being connected to the grid as well, you need to have an approved inverter. This is how the city ensures they grid remains safe and people don't get electrocuted when working on the grid somewhere else. I understand the reasoning behind it, I just don't like that my inverter isn't on the list. 

@h3t

Ok thanks and noted on both points. Yes that is annoying the inverter isnt on the 'approved' list. Solar is a next step for me too after the lithium installation and trying to use what i already have in place (which was inherited from the previous owner of house). I guess this means one needs to replace this component before going the solar route 

13 minutes ago, h3t said:

As mentioned previously, did it all myself. Not that hard, but obviously to get a COC I'll need to get someone in to sign-off. I have some other electrical work that needs doing around the house so I'll ask that electrician to sign off for COC. 

Re the 'approved inverter list'..not really too interested in the compensation plan (yet) but in order to generate electricity on your property while still being connected to the grid as well, you need to have an approved inverter. This is how the city ensures they grid remains safe and people don't get electrocuted when working on the grid somewhere else. I understand the reasoning behind it, I just don't like that my inverter isn't on the list. 

No off grid inverters are on the list as they cannot export into the grid. Only those that can export need to be approved like true hybrids and grid tied/string inverters. 

  • 1 year later...
  • Author

Reviving this old post because it's sort-off relevant.
The axpert gave in eventually. I've since installed a rental system from Stage Zero and now I have the hubble battery lying around and want to sell it.

Anyone know where in Cape Town (northern suburbs preferred) I can take the battery for a test so I can provide a report to whoever buys it? In my mind it's working 100%, but I want to have proof so a potential buyer doesn't try to do me in by claiming DOA or something.

 

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