Hello everyone. I am using a voltronics based inverter MKS 5K 48V system with 4 12V lead acid batteries. Suddenly I started facing backup issues with the system. I check individual battery voltages and found 2 batteries at 9V. Initially I had them changed but the issue persisted. Then I had all 4 batteries replaced with brand new batteries. But the problem is still there due to which I had to have them replaced. I am facing the following issue before and after replacement of batteries:

1) As soon as the inverter goes to backup mode even on a load under 500W the inverter would trip giving error 4 which shows low battery.
2) As soon as grid of solar power is supplied to the inverter at dead level of batteries the inverter would start charging the batteries but within 8-10 minutes show that batteries have been fully charged and the cycle of 1 and 2 keeps repeating.

Remedies I have tried so far:
1) Replaced all 4 batteries.
2) Got the battery terminals tightened double checked for any corrosion all are clean and tight.
3) Bypassed the DC circuit breaker to which batteries were connected.

When the inverter tripped showing batteries were discharged I checked the battery string voltage and it was at 48V after some rest.
The inverter doesn't show any fault code and doesn't show any abnormal behavior as to create any doubts. Expert opinion is needed.

NB: I am getting voltages from the solar panel that I should be getting. The issue happens on both Solar and grid power
Thank you

Do you have specifications on the new lead acid batteries?

How many amp hours rating, max discharge rate / max charge rate, charging voltages, equalisation voltage etc? Do you have battery balancers installed etc?

I would have opted to replace the lead acid batteries for lithium batteries rather, as they outperform lead acid and have a much longer life, as well as they can be discharged down to about 30% without negatively affecting the overall expected cycle life.

Lead Acid on the other hand, many are "standby type" batteries and don't have a high cycle life, and if discharged to 50% of capacity, regularly, will dramatically reduce the number of cycles they can do. Basically the deeper you discharge them, will end up giving you very low cycle life, maybe 1/6th of what they are rated at, compared to if they are discharged by only 25% or less.

Also you have to check the water levels in the lead acid batteries, regularly and ensure the plates inside the battery are covered with battery acid/water at all times, and only use distilled water, do not overfill, or you damage / destroy the batteries.

A typical 12v battery when fully charged should be around 13.2 - 13.4 volts or maybe more depends on the battery chemistry and specs. So you bank should be at a voltage of around 54-55 volts when fully charged.

Check the inverter battery settings are appropriate for the new batteries, float charge, constant charge, low battery cutoff voltage, and max charging amps etc. If not set correctly these settings can damage your lead acid batteries.

Also my first 5kva axpert, in its manual, recommended a minimum of a 200a/h battery bank? With a typical max discharge of around 10% -15% of the ah capacity, which would give me around 1-2 hours run time at around 24 amp (48v) load, when new. As they aged this dropped dramatically to around an hour and the load also had to be lowered as they would trip out as they got closer to the end of life.

So far the problem you describe above, makes me think that either the inverter battery settings are incorrect, the batteries are not suitable for the application, or damaged?

2 hours ago, ana said:

I check individual battery voltages and found 2 batteries at 9V. Initially I had them changed but the issue persisted. Then I had all 4 batteries replaced with brand new batteries. But the problem is still there due to which I had to have them replaced.

Good comments/suggestions from Arandoza. Here's a few more thoughts:

1 - Were the batteries all fully charged (checked with a battery hydrometer, and not just voltage...) before they were connected? If not, you would have stared with an imbalance, that would just get worse as time passes.

2 - Are the wires connecting the inverter to the batteries of the correct thickness (rating). One would need in the order of 25 square millimeter cable to connect a 100 Ah battery (depending on the length of cable...). Also, are all the interconnecting cables the same length? If not, the resistance in the cables could result in some batteries being under-charged, and again, over time, this would become worse.

3 - Is the inverter supplying sufficient power to the battery bank? If you have (say) 4 batteries connected in parallel, the inverter should provide 4 times the current required by one battery. Check if it is supplying around 1/10th to 1/20th of the battery rated ampere/hour capacity multiplied by the number of batteries in the bank.

Please provide details on the above, and also on dates for the first install, 2 battery replacement, and full replacement.

Looking forward to the additional information requested, then we could perhaps zoom in on the possible cause.

1 hour ago, Arandoza said:

Do you have specifications on the new lead acid batteries?

How many amp hours rating, max discharge rate / max charge rate, charging voltages, equalisation voltage etc? Do you have battery balancers installed etc?

I would have opted to replace the lead acid batteries for lithium batteries rather, as they outperform lead acid and have a much longer life, as well as they can be discharged down to about 30% without negatively affecting the overall expected cycle life.

Lead Acid on the other hand, many are "standby type" batteries and don't have a high cycle life, and if discharged to 50% of capacity, regularly, will dramatically reduce the number of cycles they can do. Basically the deeper you discharge them, will end up giving you very low cycle life, maybe 1/6th of what they are rated at, compared to if they are discharged by only 25% or less.

Also you have to check the water levels in the lead acid batteries, regularly and ensure the plates inside the battery are covered with battery acid/water at all times, and only use distilled water, do not overfill, or you damage / destroy the batteries.

A typical 12v battery when fully charged should be around 13.2 - 13.4 volts or maybe more depends on the battery chemistry and specs. So you bank should be at a voltage of around 54-55 volts when fully charged.

Check the inverter battery settings are appropriate for the new batteries, float charge, constant charge, low battery cutoff voltage, and max charging amps etc. If not set correctly these settings can damage your lead acid batteries.

Also my first 5kva axpert, in its manual, recommended a minimum of a 200a/h battery bank? With a typical max discharge of around 10% -15% of the ah capacity, which would give me around 1-2 hours run time at around 24 amp (48v) load, when new. As they aged this dropped dramatically to around an hour and the load also had to be lowered as they would trip out as they got closer to the end of life.

So far the problem you describe above, makes me think that either the inverter battery settings are incorrect, the batteries are not suitable for the application, or damaged?

On the inverter screen the battery bank voltage shows 54V but it reaches that level too quickly.

Battery time is set to FLd. cut off voltage is set to 43V

Thanks for the reply. The battery capacity is 230ah, Charge Amps are set at 30A when using grid power and 60A when on solar. Bulk charging voltage is set to 58.4V and float charging voltage is set at 54V and Battery balancers aren't installed.

I would have loved to do the same to replace lead acid batteries with lithium ones but unfortunately the inverter I am using doesn't have appropriate comms ports for BMS.

46 minutes ago, HennieL said:

Good comments/suggestions from Arandoza. Here's a few more thoughts:

1 - Were the batteries all fully charged (checked with a battery hydrometer, and not just voltage...) before they were connected? If not, you would have stared with an imbalance, that would just get worse as time passes.

2 - Are the wires connecting the inverter to the batteries of the correct thickness (rating). One would need in the order of 25 square millimeter cable to connect a 100 Ah battery (depending on the length of cable...). Also, are all the interconnecting cables the same length? If not, the resistance in the cables could result in some batteries being under-charged, and again, over time, this would become worse.

3 - Is the inverter supplying sufficient power to the battery bank? If you have (say) 4 batteries connected in parallel, the inverter should provide 4 times the current required by one battery. Check if it is supplying around 1/10th to 1/20th of the battery rated ampere/hour capacity multiplied by the number of batteries in the bank.

Please provide details on the above, and also on dates for the first install, 2 battery replacement, and full replacement.

Looking forward to the additional information requested, then we could perhaps zoom in on the possible cause.

The hydrometer showed proper gravity when the batteries had arrived. For wires from inverter to batteries I am using a 10mm dual core copper wire. The cable length is not more than 6 feet. The batteries are connected in series. I have changed all 4 batteries just the day before.

Thank you for the reply

2 hours ago, ana said:

The hydrometer showed proper gravity when the batteries had arrived. For wires from inverter to batteries I am using a 10mm dual core copper wire. The cable length is not more than 6 feet. The batteries are connected in series. I have changed all 4 batteries just the day before.

Thank you for the reply

Not want to the bearer of bad news but the quick charging means the batteries do not have 230Ah. I would suggest that they are overcycled as another reply earlier. If the battery back to grid is 48V they should last quite longer. I have supplied 100Ah battery used on a brick inverter and being lead acid they held up well for over 2 yrs. I still belief it is due to ever being allowed to drop below 12V per battery. For about R900 a battery balancer is cheap vs battery cost.

I also agree with not discharging at more than the 15% Ah capacity. The same level for charging. As your charge rate is below this it would not be related to this metric.

At this stage it seems those batteries don't seem to be very healthy.

Your charge levels do seem to be good for lead acid.

My personal level for charged lead acid after hours of resting do seem to suggest 12.8-13V per battery.

2 hours ago, ana said:

I would have loved to do the same to replace lead acid batteries with lithium ones but unfortunately the inverter I am using doesn't have appropriate comms ports for BMS.

If the inverter does not have comms port for a BMS then you use the USE setting on the inverter and set the voltages manually.

2 hours ago, ana said:

I am using a 10mm dual core copper wire. The cable length is not more than 6 feet.

I am curious, why did you specify the cable length in feet and the thickness in mm and not AWG?

3 hours ago, ana said:

unfortunately the inverter I am using doesn't have appropriate comms ports for BMS.

I am using the Axpert type inverters without a BMS port and make use of the USE - user defined battery setting on the axperts, with lithium cv / fv / max charge etc settings appropriate for the 12 x Pylontech UP5000 batteries, as per pylontech :)

When I used lead acid, about 4 years ago (Trojan TE35's x 8 (6v) also about 230ah), I used 25mm2 squared cable from the inverters to the battery bank and between the batteries, connected to positive on the first battery and then the negative on the last battery. I kept the cables to the each inverter the same thickness 25mm2 but connected all the inverters to bus bars, and then connected the up5000's in pairs of 3 to the same busbars, each pair of 3 up5000's with a suitably fused connection max160amp, although 3 x up5000's could give recommended max 50amps x 3 continuously, or 80amp x 3 for a few seconds.

To monitor the axperts and Lithium batteries I use a free software called multisib, ( http://www.multisibcontrol.net )which can read the pylontech BMS and the info from the inverters. As the Axpert battery info is totally incorrect regardless of what battery type you use, as it does not make use of a shunt to accurately measure the power used, but rather it uses the voltage it detects as a representation of charge level, and when one puts on a big load, especially with lead acid, the voltage can drop suddenly, then the inverter thinks the batteries are fully discharged and it can drop the load. Which is why as they aged I had to adjust my maximum load at night during load shedding. However during the day while the solar was pumping it was not really a problem.

So currently my axperts flash a 04 code when they think the lithium batteries are low, however with the reporting on the Multisib software from pylontech BMS info, one can see SOC and SOH etc which is operating normally, so I totally disregard the axperts battery reporting as it is incorrect, however the axperts still flash 04 - battery low on the display :)

Other suggestions, one could check your batteries for hot spots? touch them on the sides, they maybe cooler than your hand but not warm, when charging, if they seem a bit warmer this maybe normal but may also suggest overcharging, equalizing too often? should only be done occasionally, maybe at most once a month (lead acid) or every 6-8 weeks etc. not daily. Equalisation does not always apply to lithium banks? And It seems one would keep it off, unless specified by the lithium to turn to it on?

Have you done voltage measurements of the bank when its charging? and/ or, once it appears full? Again the Spec sheets for the battery make/model will include C-rates in other words the expected run time at a certain amp loading for the model of battery? The lower the load the longer the run time, and its not a straight line discharge rate ( Peukerts Law - for lead acid).

Last thought is that Mixing old and new lead acid batteries does not work, at all. A bit like having a one flat battery and one good battery in a TV remote? :) and it will likely to damage the new batteries as they will dicharge continuously trying to balance or charge the other 2 seemingly ok batteries.

I trust you replaced a 4 batteries at the same time did not use any of them with the 2 older seemingly ok batteries?

I think if one did this and left them for 12 or 24 hours there's a good chance of damaging the 2 new ones?

Running out of ideas :0

Final thoughts, if the inverter(s) are supplying a charge, but the bank is not holding the charge, it typically points to bad batteries or higher loads than the bank can not support?

For lead acid, folks used to use the Victron BMV700 / BMV702 / BMV712 battery monitor which used a shunt and could accurately measure lead acid, agm, sla or lithium, and you can calibrate them as well. See the link below they have some videos as well for more info on how they work, how to connect etc. very good products.

https://www.victronenergy.com/battery-monitors

You mention the voltage of 48v after rest, but the important voltage is when the trip occurs. The pack can only be as strong as it's weakest link. The perhaps check your settings as well at which voltage it is set at for low charge.

As mentioned previously, if the wiring is too thin, it will cause issues.

I seem to remember reading that charging LA batteries at more than 10% of their total capacity will damage them, so charging at 30 and 60A will destroy your 230A battery

Edited May 25, 20251 yr by dax021

Some further thoughts:

1. It is standard good practice to not discharge lead acid batteries to below 50% capacity. If I understood your previous responses correctly, you have 4 x 12V 230Ah batteries connected in serial, thus 48V 230Ah. 50% of the rated capacity is thus 115Ah, or 115 x 48 = 5.5kWh.

2. Given that lead acid batteries should not be charged or discharged more rapidly than C/10 (for long life), the batteries should be charged at about 22.5A maximum. Taking internal losses in the battery and inverter (say 95% and 90% efficiency respectively...) into account, and charging at 22.5A, the charging time would be about (5520Wh/0.95/0.90)/(22.5*48) = 6.0 hours minimum to replace 50% of the battery's full capacity.

3. With a 5.5kWh capacity, and a maximum battery discharge rate of 1.08kW (22.5Ax48V), you would thus have approximately 5 hours discharge at maximum 1kW power draw.

Could your problem perhaps stem from not charging your batteries for long enough to replace what was consumed before the next withdrawal?

On 2025/05/25 at 7:22 AM, ana said:

I check individual battery voltages and found 2 batteries at 9V. Initially I had them changed but the issue persisted. Then I had all 4 batteries replaced with brand new batteries. But the problem is still there due to which I had to have them replaced. I am facing the following issue before and after replacement of batteries:

I'll avoid pointing out that by now you could have bought lithiums. Did you buy the right kind of replacement batteries? There are batteries meant for starting motors and batteries for UPS systems and they are the same shape and size and generally superficially similar, but they have very different characteristics. One type is meant to deliver a lot of current in short bursts, the other is designed to deliver lower current but for sustained periods. The latter are sometimes referred to as "deep cycle".

I had a neighbour who had a UPS type system to keep his TV and a couple of lights working through load shedding. Eventually the batteries that came with the system ran out of steam and he went to a local shop who told him it was easy peasy, of course they could get those. And he was very unhappy with the results.

I explained to him about the different types of battery and sent him to a UPS specialist with a good reputation, whose business is UPS and so they know what kinds of batteries are appropriate. They asked him what he was trying to back up so as to figure out what the maximum load would be, then fitted what they deemed to be the appropriate battery.

After the next load shed he was smiling. He watched his favourite programs in a lit room, which was what he wanted.

On 2025/05/25 at 4:08 PM, Scorp007 said:

Not want to the bearer of bad news but the quick charging means the batteries do not have 230Ah. I would suggest that they are overcycled as another reply earlier. If the battery back to grid is 48V they should last quite longer. I have supplied 100Ah battery used on a brick inverter and being lead acid they held up well for over 2 yrs. I still belief it is due to ever being allowed to drop below 12V per battery. For about R900 a battery balancer is cheap vs battery cost.

I also agree with not discharging at more than the 15% Ah capacity. The same level for charging. As your charge rate is below this it would not be related to this metric.

At this stage it seems those batteries don't seem to be very healthy.

Your charge levels do seem to be good for lead acid.

My personal level for charged lead acid after hours of resting do seem to suggest 12.8-13V per battery.

First of all sorry for being late to reply and Thank you for your kind concern and reply.

I have still been in the same mess where I was earlier. Though Batteries are brand new, however I too was skeptical about them being the culprits. Therefore I connected them to another inverter just to be sure. Interestingly with 3 hours are of grid power supply and no load to the batteries at all the inverter managed to charge them only to a level of 49.2V. Then of course I had to return the borrowed inverter back to the friend. But when again I connected my inverter back the story was the same the only difference was that the charge put by the borrowed inverter survived quite longer with load on the batteries in the back up mode. But whatever charge was drained was never actually recharged by my inverter really.

Thank you

On 2025/05/25 at 4:16 PM, GerhardK83 said:

If the inverter does not have comms port for a BMS then you use the USE setting on the inverter and set the voltages manually.

I am curious, why did you specify the cable length in feet and the thickness in mm and not AWG?

Thank for the reply.

That is because of the bad habit of using metric and imperial systems. It's a long story.

On 2025/05/25 at 6:09 PM, Arandoza said:

I am using the Axpert type inverters without a BMS port and make use of the USE - user defined battery setting on the axperts, with lithium cv / fv / max charge etc settings appropriate for the 12 x Pylontech UP5000 batteries, as per pylontech :)

When I used lead acid, about 4 years ago (Trojan TE35's x 8 (6v) also about 230ah), I used 25mm2 squared cable from the inverters to the battery bank and between the batteries, connected to positive on the first battery and then the negative on the last battery. I kept the cables to the each inverter the same thickness 25mm2 but connected all the inverters to bus bars, and then connected the up5000's in pairs of 3 to the same busbars, each pair of 3 up5000's with a suitably fused connection max160amp, although 3 x up5000's could give recommended max 50amps x 3 continuously, or 80amp x 3 for a few seconds.

To monitor the axperts and Lithium batteries I use a free software called multisib, ( http://www.multisibcontrol.net )which can read the pylontech BMS and the info from the inverters. As the Axpert battery info is totally incorrect regardless of what battery type you use, as it does not make use of a shunt to accurately measure the power used, but rather it uses the voltage it detects as a representation of charge level, and when one puts on a big load, especially with lead acid, the voltage can drop suddenly, then the inverter thinks the batteries are fully discharged and it can drop the load. Which is why as they aged I had to adjust my maximum load at night during load shedding. However during the day while the solar was pumping it was not really a problem.

So currently my axperts flash a 04 code when they think the lithium batteries are low, however with the reporting on the Multisib software from pylontech BMS info, one can see SOC and SOH etc which is operating normally, so I totally disregard the axperts battery reporting as it is incorrect, however the axperts still flash 04 - battery low on the display :)

Other suggestions, one could check your batteries for hot spots? touch them on the sides, they maybe cooler than your hand but not warm, when charging, if they seem a bit warmer this maybe normal but may also suggest overcharging, equalizing too often? should only be done occasionally, maybe at most once a month (lead acid) or every 6-8 weeks etc. not daily. Equalisation does not always apply to lithium banks? And It seems one would keep it off, unless specified by the lithium to turn to it on?

Have you done voltage measurements of the bank when its charging? and/ or, once it appears full? Again the Spec sheets for the battery make/model will include C-rates in other words the expected run time at a certain amp loading for the model of battery? The lower the load the longer the run time, and its not a straight line discharge rate ( Peukerts Law - for lead acid).

Last thought is that Mixing old and new lead acid batteries does not work, at all. A bit like having a one flat battery and one good battery in a TV remote? :) and it will likely to damage the new batteries as they will dicharge continuously trying to balance or charge the other 2 seemingly ok batteries.

I trust you replaced a 4 batteries at the same time did not use any of them with the 2 older seemingly ok batteries?

I think if one did this and left them for 12 or 24 hours there's a good chance of damaging the 2 new ones?

Running out of ideas :0

Final thoughts, if the inverter(s) are supplying a charge, but the bank is not holding the charge, it typically points to bad batteries or higher loads than the bank can not support?

For lead acid, folks used to use the Victron BMV700 / BMV702 / BMV712 battery monitor which used a shunt and could accurately measure lead acid, agm, sla or lithium, and you can calibrate them as well. See the link below they have some videos as well for more info on how they work, how to connect etc. very good products.

https://www.victronenergy.com/battery-monitors

Thank you for the reply.

I have felt the batteries for hotspots during charging multiple times the batteries were not hotter than room temperature. And yes these 4 batteries are brand new and none of them has ever been mixed with old batteries.

On 2025/05/25 at 10:34 PM, Pho3niX90 said:

You mention the voltage of 48v after rest, but the important voltage is when the trip occurs. The pack can only be as strong as it's weakest link. The perhaps check your settings as well at which voltage it is set at for low charge.

As mentioned previously, if the wiring is too thin, it will cause issues.

Thank you for the reply.

Even when the trip occurs none of the batteries is below 12v

On 2025/05/28 at 11:01 PM, HennieL said:

Some further thoughts:

1. It is standard good practice to not discharge lead acid batteries to below 50% capacity. If I understood your previous responses correctly, you have 4 x 12V 230Ah batteries connected in serial, thus 48V 230Ah. 50% of the rated capacity is thus 115Ah, or 115 x 48 = 5.5kWh.

2. Given that lead acid batteries should not be charged or discharged more rapidly than C/10 (for long life), the batteries should be charged at about 22.5A maximum. Taking internal losses in the battery and inverter (say 95% and 90% efficiency respectively...) into account, and charging at 22.5A, the charging time would be about (5520Wh/0.95/0.90)/(22.5*48) = 6.0 hours minimum to replace 50% of the battery's full capacity.

3. With a 5.5kWh capacity, and a maximum battery discharge rate of 1.08kW (22.5Ax48V), you would thus have approximately 5 hours discharge at maximum 1kW power draw.

Could your problem perhaps stem from not charging your batteries for long enough to replace what was consumed before the next withdrawal?

Thank you for the reply.

So far what I have believed is that, the MPPT system doesn't allow the battery to be discharged to those levels please correct me if I am wrong. As cut off voltages only have certain lower limit.

Thank you

On 2025/05/29 at 12:04 PM, Bobster. said:

I'll avoid pointing out that by now you could have bought lithiums. Did you buy the right kind of replacement batteries? There are batteries meant for starting motors and batteries for UPS systems and they are the same shape and size and generally superficially similar, but they have very different characteristics. One type is meant to deliver a lot of current in short bursts, the other is designed to deliver lower current but for sustained periods. The latter are sometimes referred to as "deep cycle".

I had a neighbour who had a UPS type system to keep his TV and a couple of lights working through load shedding. Eventually the batteries that came with the system ran out of steam and he went to a local shop who told him it was easy peasy, of course they could get those. And he was very unhappy with the results.

I explained to him about the different types of battery and sent him to a UPS specialist with a good reputation, whose business is UPS and so they know what kinds of batteries are appropriate. They asked him what he was trying to back up so as to figure out what the maximum load would be, then fitted what they deemed to be the appropriate battery.

After the next load shed he was smiling. He watched his favourite programs in a lit room, which was what he wanted.

Thank you for the reply.

Yes the batteries are tall tubular deep cycles ones

Thank you

A little update from my side.

A local technician suggested replacing the charge controller which I did but with no different results. In frustration I bought a new inverter which is lying in the box. I am having some afterthoughts could the problem be due the premature float bug?

Thank you

3 hours ago, ana said:

A little update from my side.

A local technician suggested replacing the charge controller which I did but with no different results. In frustration I bought a new inverter which is lying in the box. I am having some afterthoughts could the problem be due the premature float bug?

Thank you

Where are you based? Province/town/city.

43 minutes ago, Scorp007 said:

Where are you based? Province/town/city.

I am from Pakistan. I guess other three parameters would be irrelevant.

With these types of batteries voltage can be misleading when the CCA has dropped. I would suggest buy a battery equalizer, preferably one where you can connect via bluetooth to investigate when this happens. It also helps to ballance them.

To me, if the voltages are fine when the drop occurs, it might be your inverters settings.

11 hours ago, ana said:

Thank you for the reply.

So far what I have believed is that, the MPPT system doesn't allow the battery to be discharged to those levels please correct me if I am wrong.

Thank you

I don't think that the MPPT can regulate the discharge rate of a battery when supplying power to an inverter... Just to complete the picture for us, please tell us:

• How many solar panels (and of what capacity (Watt) and voltage) do you have hooked up to the MPPT?

• Are the panels connected in series or in parallel?

• Is the MPPT then connected directly to your battery, or is it connected to your inverter?

Thanks

10 hours ago, HennieL said:

I don't think that the MPPT can regulate the discharge rate of a battery when supplying power to an inverter... Just to complete the picture for us, please tell us:

• How many solar panels (and of what capacity (Watt) and voltage) do you have hooked up to the MPPT?

• Are the panels connected in series or in parallel?

• Is the MPPT then connected directly to your battery, or is it connected to your inverter?

Thanks

On the Axpert you have no control where the MPPT is connected as the inverter can supply the load and/or charge the battery. Solar input is connected on the inverter that goes to the MPPT or PWM controller on the lower spec models.

With a new inverter bought we will see how the batteries behave.

13 hours ago, HennieL said:

I don't think that the MPPT can regulate the discharge rate of a battery when supplying power to an inverter... Just to complete the picture for us, please tell us:

• How many solar panels (and of what capacity (Watt) and voltage) do you have hooked up to the MPPT?

• Are the panels connected in series or in parallel?

• Is the MPPT then connected directly to your battery, or is it connected to your inverter?

Thanks

I have 8 solar panels 500W each 2 strings of 4 in series in each then the two strings are connected in parallel that go to the inverter