Eish

@Modina thanks for your replies. I have left the unit unearthed. I do have a fairly nice audio system and have not heard any noise, so that's good news.

In view of all the above posts, I have decided not to ground my system. Thank you for all the posts and information - I really appreciate it. My new system is working well. I have doubled my battery bank capacity to make use of the extra "free" power. Thanks for all the replies and @Bobster. I understand your concerns regarding your voluntarily deleted post - I read it - please understand, everyone needs to learn. For some people, it is via university, technikon, school fees past matric, youtube, etcetera. That's the way the world works. Begrudging people that opportunity would be wrong. Even you had to start from the beginning. 😃

Thanks, I also works to read the manual 🤣 Step 3：Grounding XTRA N series is a common-negative controller, where all the negative terminals of PV array, battery and load can be grounded simultaneously or any one of them will be Figure 2-2 Schematic of wiring diagram 11 grounded. However, according to the practical application, all the negative terminals of PV array, battery and load can also be ungrounded, but the grounding terminal on its shell must be grounded, which may effectively shield the electromagnetic interference from the outside, and prevent some electric shock to human body due to the electrification of the shell. CAUTION: For common-negative system, such as motorhome, it is recommended to use a common-negative controller; but if in the common-negative system, some common-positive equipment are used, and the positive electrode is grounded, the controller may be damaged.

Thanks for your reply Scorp007. Perhaps an AC earth point? The manual only says "Grounding - Common Negative"

Thanks for the info Kalahari Meerkat. The series connection worked a charm! Much neater and less wires. I bought MC4 connectors to connect the panels to the MPPT, only to find out yesterday when I had time to do the work, that the MC4 connectors I bought did not have the metal male and female lugs supplied. Being a Saturday, the place I purchased it from was closed, I scrambled to find new ones with the lugs. The learning curve has been steep. (But enjoyable, with thanks to this forum and it's members!) I will have time tomorrow to finish the cabling and test the setup, just in time for a 3 week away-from-home mission. However, I will leave the system disconnected when I am away so I can properly monitor it when I am back home though. But, I digress ... my MPPT controller has an earth screw connection. Do I just connect an earth wire from the battery cable there?

@Kalahari Meerkat I have decided to follow your advise and do the series installation, reason being, is that now I do not have to move my inverter and battery. Unfortunately, that meant I had to buy extra cable, R550 later, considering the all benefits, this is a win-win situation. Update to follow and again, thank you for pointing out that MPPT controllers can use low amperes and convert that to high.

Thanks for your reply Meerkat! The learning curve is steep. Fortunately my current runs are short so parallel is not that expensive, I have the cable already. However, I wish I knew this earlier.

Thanks Kalahri Meerkat for your reply. if I connect in series, the amps going in will only be about 4amps . I always thought that the higher the current going into the battery, the faster it charges? That's why I want to do the parallel connection to ramp the amps up to about 16A.

Thanks guys, you have been awesome! I ordered the panels and MPPT. This is the MPPT. I hope it's ok, I don't know the brand. My budget is very small so this was about all I could afford. https://www.sustainable.co.za/products/epsolar-xtra-3210n-30a-12-24v-mppt-charge-controller-with-lcd-display?_pos=3&_psq=mppt-30a&_ss=e&_v=1.0 Features Advanced MPPT technology & ultra-fast-tracking speed is up to 99.5 % guaranteed. Advanced Display unit XDS2 for easier functionality Maximum DC/DC transfer efficiency is as high as 98 %,full load transfer efficiency is up to 97.4 %. Wide MPP operating voltage range. Low temperature protection and self-activate function for lithium battery charging. Limit charging power & current overrated range. Real-time energy statistics function. Multiple load work modes. Comprehensive electronic protection. Compatible with lead acid and lithium-ion batteries. Over temperature protection and power degrading in higher temperature. Optional LCD display units (XDB1/XDS1/XDS2) and accessories. High quality and low failure rate components of ST or IR to ensure service life. Isolated RS485 communication port with 5V/200mA protected output, with standard Modbus protocol. Monitor and set the parameters via APP or PC software. Dustproof and waterproof design with IP32 protection class. CE certification(LVD IEC62109,EMC EN3/1-6-61000). Electrical Model: XTRA 3210N System Nominal Voltage: 12/24VDC Auto Rated Charge Current: 30A Rated Discharge Current: 30A Battery Voltage Range: 8～32V Max. PV Open Circuit Voltage: 100V Max. PV Input Power (W/V): 390/12 or 780/24 Equalization Voltage: Sealed(14.6V); Flooded(14.8V); User(17~9V). Boost Voltage: Gel(14.2V); Sealed(14.6V); Flooded(14.8V); User(17~9V). Float Voltage: Gel /Sealed /Flooded(13.8V); User(17~9V). Grounding: Common negative grounding. Self-consumption: ≤35mA(12V); ≤22mA(24V). Discharge circuit voltage drop: ≤0.23V. RS485 interface: 5VDC/200mA (RJ45). LCD backlight time: 60S (Default).

So my idea is to connect 4 x 70W Mono panels in parallel via MPPT (or PWM) controller to the battery. Maximum Power Voltage: 18.31 V. Maximum Power Current: 3.83 A. Open Circuit Voltage: 22.65 V. Short Circuit Current: 4.04 A. Please confirm this will work with my battery in parallel connection?

Thank you very much!

I have a small basic 12V inverter charger setup with a Lifepo4 battery. I would like to add 200W of solar panels to my setup. Can it be done? The inverter charger has no other connections other than AC and DC in and then AC out Please help?

I am learning so much. Thank you guys. I am going to connect them all in parallel and leave them for a day.

Thank you Plonkster for your very good explanation. I was under the impression the cells should all be the same. It is all starting to make sense for me now. OK, so nothing wrong with the cells, nothing wrong with the BMS or the charger. Phew! The fact that I am OCD does not help. 😉

I monitored the charger during the charge session. It stopped charging at 14.2V. Cell one measured 3.71V. Cell 2 3.57 Cell 3 3.35 Cell 4 3.35. Is there a problem with cell 1? Or should I connect all the cells in parallel to balance?