Hi. 

I have an opportunity to acquire a 5Kw Mecer SOL-I-AX-5KP inverter at a good price. Any opinions on this inverter specifically? 

My initial requirements will be for 1,5Kw backup. I am looking at buying a 48V 200ah Lithiam battery (am considering Gel also as it is a fifth of Lithiam price), combined with 4x565W solar panels. Would this be a suitable combination, especially considering I'm not using full 5Kw of inverter.

Thanks in advance

1 hour ago, Rob23 said:

I am looking at buying a 48V 200ah Lithiam battery (am considering Gel also as it is a fifth of Lithiam price)

Can't comment on the inverter as i haven't installed one yet, but what i can comment on is the battery backup rather bite the bullet and invest in Lfp(lifep04),  gel batteries won't serve you well considering the current load shedding stages and it might get worse so definetly go for lithuim you won't regret it. 5 hours between current load shedding stages is not long enough to charge gel( LA) you need approx 12 hours to fully charge gel.

From what I can see that's the Mecer-branded version of the Axpert King 5kW inverter, which you could also buy under the Kodak King brand. You could try searching for opinions and issues on those also.

Lithium should be much better value in the long run, in spite of the initial cost layout.

 

Bought that model inverter from Voltex in mid-May.  It lasted 10 days in the customer's house with a SHOTO 5100wH battery.

Without warning during normal mains-on period, the buzzer sounded and the inverter switched itself off.  The battery ALM light was on.  

Discomnected the battery, restarted it to find the SOC to be 100% with 53.5V.

But a dead-short on the inverter battery in.  After some argument with Voltex, they examined it and said there is an internal fault

The fellow at the counter said they had sold 29 of these in a 6-week period and had 3 back.  A bit surprising I thought

The short on the Mecer inverter battery terminals damaged the battery

Ths supplier has quoted R4750 to replace the BMS and restart the battery.  The inverter supplier, Voltex deny it is their responsibility 

Would a battery short damage a BMS? 

Edited September 8, 20233 yr by chrisc

Yes it would

12 hours ago, chrisc said:

The short on the Mecer inverter battery terminals damaged the battery

Ths supplier has quoted R4750 to replace the BMS and restart the battery.  The inverter supplier, Voltex deny it is their responsibility 

Would a battery short damage a BMS? 

No , the BMS has been designed for a reason , that is to protect the backend chemistry from , inter alias , over voltage , overload current and short circuit current. That is why the BMS exist in the first place , no other reason (EDIT : except cell-balancing and reporting SOC) . Now if the BMS fails when it is supposed to carry out its duty , then it is obvious that the BMS is not fit for purpose , or it has experienced a failure mode for which the customer cannot be hold responsible for .  With the exception of the customer exposing the battery terminals with an excessively high dc voltage (example 300VDC!)  , which will cause such BMS to catastrophically fail. But in the case of a short circuit , NO , the bms should not fail. It is equipped to (a) detect the short circuit current within a certain time window , and (b) to negate its FET switches so the short is removed from the backend chemistry.

Edited September 9, 20233 yr by BritishRacingGreen

This is the email below (in italics) sent to Voltex after their technician had examined it.   I was on site with my electrician and the house owner, and we were not impressed with the conduct of this lady tech

Despite me telling her that there was a 0,4 ohm resistance across the battery terminals, she insisted that the battery be reconnected and tried for several minutes to get a DC reading across the battery terminals.   She did not seem to understand that a short-circuit would cause a 0V reading on a meter and said my (Fluke) meter must be faulty.  She got out her cheapie clamp meter and got the same result.  Then she said there was an unknown fault

Start:  

This inverter is not behaving as it should

When the new inverter was reconnected on 29th August, the 4 SOC indicators on the battery were all on.  The voltage was 52.1 and within 45 mins had got to 54.0V

The customer told me that on 30th August, only 2 SOC lights were on, despite there being mains electricity on for 8 hours

I went to site on 31st August and found the following

2 SOC lights were on and the battery display showed 0.55A input.  I switched the inverter off and back on, the inverter's fan came on and the input changed to 11.2A

On 1st September the battery SOC was down to 1 light and the input showed 0.31A.  Again, switching the inverter off, waiting 2 mins and switching back on made the input change to 12.4A,   The battery showed 4 SOC lights by 09h00 on 2nd September

Today at 08h45 the battery is showing 3 SOC lights, 52,0V and input 1.1A, dropping to 0.18A or 0.01A.  By the time I left at 11h30 it was down to 2 SOC lights.   Mains is on all the time

The inverter should charge at a constant rate until the battery reaches a float level of 54.0V.   It is not doing this and when there is load-shedding, switches off after 20 mins.  The battery type is "Use"

The load displayed by the inverter is 580 watts.   There are no electric +heaters in the house and the stove and geyser are not connected to the inverter circuit 

End:

This elicited no response

I took the battery to the supplier and he gave me a replacement.  It has worked 100% since then.  I assume that what the battery supplier told me about the BMS is correct.  The charge voltage of this inverter is set to 56.4 and float 54.0.

The Akkutech battery has a 105 a/h rating

 

 

Despite me telling her that there was a 0,4 ohm resistance across the battery terminals, she insisted that the battery be reconnected

Yikes! 😮

But she is an expert, paid a salary for her erm... knowledge

Received a reply from Voltex:  "We are confident that the technician applied her knowledge correctly to resolve the problem.  We cannot be responsible for failures in equipment not supplied by this company"

Voltex refuse to accept any responsibilty for the actions of their technician who, due to her action. caused R4750 worth of damage to the customers equipment

The excuses heard were astonishing

"We have never heard of the battery make you use, so it is not our responsibility"

"We have never heard of the supplier you purchased the product from and therefore dispute their alleged repair"

This despite having purchased many hundreds of thousands of Rand of electrical items from them since 1980

Brand loyalty means nothing to them.   There are plenty of other customers for Voltex, we don't need you

I am using the exact same inverter for exactly 4 years, without issues... Then, last week, it started showing issues when recharging the 10kw/h battery pack... But than again, it worked hard - even been abused on occasion... It is rated at 4.5kw constant and I use 4.5km constant 😁