ErichK

Thanks Heath. Where are you based and how much would you sell it for?

Hi everyone. Does anyone know where I can start looking for a 120Ah lithium cell? I have a 48V battery with 1 dead cell. The others are still fine. I suppose an old 140 or 200Ah cell will also work. I hope someone can help.

I haven't removed and tested all the capacitors yet. I just tested the relays I could find and they all work. I could carry on replacingnparts and hoping for the best. But as a former technician, I don't believe that wont be productive time. I don't have all the test equipment and bench like in my technician days so I'm at the end of what I can test without powering up the boards and taking measurements. I'll have to make another plan.

Will do and let you know. Probably only next weekend though.

Hi Coulomb, yeah I had that same thought, it was fun though. I can think of worse ways to waste my time with. I should have mentioned that the battery voltage didn’t drop this time. Stayed at 52V. The inverter just switched off. No clicks or beeps or anything. To test I used my battery while it was connected to my other inverter. The other inverter didn't sshow any indication of an issue when I switched the faulty one on. I can hear relays switching when my working inverter starts up, with this one there are no sounds. Do you think it might be a relay or relay drive circuit?

I opened it up today and replaced the 2 x 1000uF caps on the mainboard that are usual suspects in these inverters. But it did not fix it. Inverter powers up, but then it doesn't start inverting. No relay clicks. Just shuts down again after a minute or so. I'll start pulling out relays and check if there are any faulty ones. Maybe I'll replace all the caps around that power supply circuit.

Batteries from the future! 😆. Seriously, I bought mine from these dogdy types some time ago without doing the research. I got lucky and my battery still works great 4 years later but it was not a pleasant experience getting it. It was not a new battery either. I know of some that only lasted a year. Stay away and warn others.

Hi ErichV, I'm going to send mine up to TSP at some point when budget allows.

That looks great thank you. Definitely going to plagiarize it.

Morning all. I have 14 120ah lifepo4 cells from an old 15 cell 48V battery, 1 cell failed. I am considering building a 360ah 12V battery using 12 of the good cells to use in a mobile application with a 12V 1500W inverter that I have lying around. Can the forum please assist with: 1. Recommend a BMS? 2. Recommend a charger? 3. Recommend a balancer? 4.Protection requirements for a safe system? 5. Best/safest configuration? I.e 3 x parallel cells then 4 sets in series, or 4 x series cells and 3 sets in parallel. 5. Housings? Thinking of a timber box? I'm sure someone has built this before, looking forward to the info. Thanks In advance.

Hello all, I downloaded software called MultiSIB. It works very well with my 5kW Mecer Axpert inverter. I have an old laptop connected to it permanently. (Better than throwing it in the e-waste bin). I dial in using Teamviewer on my phone from anywhere. I can change settings on the fly as loadshedding changes. I don't know if the software is still supported but it doesn't matter, it works on the old machine running Windows 7.

Can one parallel axpert type inverters from different brands? I.e. 5kW Mecer and a 5kW TheSunPays. They look the same, program and functions the same.

2 months they said, so only half decent.

TSP says +-R3k for refurbished motherboard. Not bad if you compare to the price of a new inverter.

Ok, it is a 500km drive for him.

Thanks for letting me know. I'll tell dad to take it in. We'll call them in the morning.

.......and it worked for 24h, then the same symptom again. Shuts down. Replacing it now.

So my Dad opened it up and let his electronic technician friend have a look. Couldn't see anything visibly damaged or burnt. He did solder one spot that looked like a dry joint. Put it back together and has been working fine for a day now. Who knows for how long but we can only hope. It is going to hurt the pentioners' budget if he has to replace it now.

Hello all, Our TSP 5kw Axpert type inverter is doing a weird thing. As after connecting the battery, the inverter turns on momentarily, then the battery voltage drops to about 32V and the inverter shuts down again. Battery is brand new and sitting at 54V. It almost seems like there is a relay that causes a short circuit somewhere. Any ideas?

I bought a 7.2kW one about a year ago and my dad and cousin bought 6kW batteries about 2 years ago. My dad and I, on seperate occasions didn't pay upfront and insisted on collection in Midrand. Dodgy as hell. The battery was not new, the bms doesn't work and the box was just sprayed with some black spray paint. That said, I took the chance. Battery has been performing very well and delivers no less than 6.5kWh most days for a year now. Ditto for the one my cousin bought(he was brave and opted for delivery, amazingly it arrived). My dad unfortunately was not so lucky. His battery packed up in January. I suspect it is due to the high temperatures in the attic in Limpopo and over charging that one of the cells died. The other 14 are fine but the battery is useless. It is a chance we took and accepted at the time there is no guarantee and made peace to potentially be scammed. So far so good. Would I do it again or recommend it to anyone, not a chance! I still feel guilty every time I look at it knowing it might have been stolen from a cell tower somewhere. My dad now bought a proper 51.2V well known brand of battery from a retailer in town and has peace of mind that warranty and backup service is in place. That is the way to go.

Thanks everyone for the valuable feedback. I see there are too many risks with this setup. I'm going back to the drawing board.

Thanks Coulomb, the batteries are Hubble S100 12V lithiums with a 1C charge/discharge rating. The geyser element will be replaced with a 2kW element. That equals about 83A at 24V. It is high, I know. There will be 3kW of solar on the roof charging via 2 x 60A mppt's and the geyser will only run during day time and one hour in the morning. My maths is very basic and I hope I'm not missing some other dynamic that will influence the performance.

Hello All, I want to know if I can connect 2 x Must 3kW inverters to the 24V battery bank? The two won't be paralleled and will supply seperate circuits (1 is for the lights and fridges the other for the geyser). They will each have 2 or 3 x 550W solar panels to charge the batteries in parallel. What can go wrong?