Hi - new here but need some advice. My mother is on an oxygen 24hrs a day - the oxygen concentrator is a 700W unit. To date i have been through 2 systems - the first was a deltec inverter with a Deltec 12V 200Ah AGM battery - this lasted less than a year and cost us about R10k - the place i bought it from, MAL Batteries then told us there was only a 3 month warranty and tried to sell me a small mobile system for R15k.

I then bought a new inverter from Rubicion and a Mecer LiFePO4 12.8v 200Ahbattery. this has lasted just over a year and the battery doesn't last a half hour during load shedding - of course the battery has a 1 year warranty - which expired last month!!

I really need to get a proper reliable setup that could possibly also run her DSTV and TV while the electricity is down. If there are any experts out there that could point me in the right direction it will be greatly appreciated

3 hours ago, IanSwart said:

Hi - new here but need some advice. My mother is on an oxygen 24hrs a day - the oxygen concentrator is a 700W unit. To date i have been through 2 systems - the first was a deltec inverter with a Deltec 12V 200Ah AGM battery - this lasted less than a year and cost us about R10k - the place i bought it from, MAL Batteries then told us there was only a 3 month warranty and tried to sell me a small mobile system for R15k.

I then bought a new inverter from Rubicion and a Mecer LiFePO4 12.8v 200Ahbattery. this has lasted just over a year and the battery doesn't last a half hour during load shedding - of course the battery has a 1 year warranty - which expired last month!!

I really need to get a proper reliable setup that could possibly also run her DSTV and TV while the electricity is down. If there are any experts out there that could point me in the right direction it will be greatly appreciated

A 12v system with 200Ah battery will work itself to death during l/s, maybe the reason your batteries failed just after a year?

Get at least a 3kw inverter and one 5kw battery - some units (in 5kw inverter and battery) is 10yr warranty.

4 hours ago, IanSwart said:

Hi - new here but need some advice. My mother is on an oxygen 24hrs a day - the oxygen concentrator is a 700W unit. To date i have been through 2 systems - the first was a deltec inverter with a Deltec 12V 200Ah AGM battery - this lasted less than a year and cost us about R10k - the place i bought it from, MAL Batteries then told us there was only a 3 month warranty and tried to sell me a small mobile system for R15k.

I then bought a new inverter from Rubicion and a Mecer LiFePO4 12.8v 200Ahbattery. this has lasted just over a year and the battery doesn't last a half hour during load shedding - of course the battery has a 1 year warranty - which expired last month!!

I really need to get a proper reliable setup that could possibly also run her DSTV and TV while the electricity is down. If there are any experts out there that could point me in the right direction it will be greatly appreciated

easiest is to just replace the batteries, chances are the batteries supplied were B grade. There are some locals that sell prismatic cells. Do not buy AGM, as they will only last around a year, maybe a year and a halve if you are lucky.

One other thing you can try first, is to balance the batteries, as I am almost certain there is no balancer for the 4 cells.

Edited March 9, 20251 yr by Pho3niX90

Just a layman's 2c worth. Agree with @Demo Not a trolley inverter or a plug-in-the-wall, and not a modified-sine-wave inverter, not an AGM battery or even rather not a drop-in Lithium alternative. Best a professionally installed good brand name system, with CoC, with BMS comms between inverter and battery, and a remote monitoring assistant. Maybe with some redundancy like 2x Pylontech USC2000 batteries instead of a single 5kWh battery, with a Victron MultiPlus-II GX - 48/3000/35-32.

Again, not professional advice, just some thoughts you could discuss with an installer. Might surely be other better systems you could also consider.

Although I agree having a BMS with comms to BMS if one has reasons to use 12V drop inns they can perform very well. I have been using it for 3 yrs. The remote monitoring for me would also be essential due to the nature of the system being medical reasons.

I am using the drop inns on my Deye 5kW as seen below.