Victron Multiplus-II vs Sunsynk 5kW — which inverter for SA loadshedding backup?
This comes up constantly so let me give you the detailed breakdown based on real-world experience in Bloemfontein.
The technology: The ecosystem is the strongest argument for Victron. SmartSolar MPPT, SmartShunt, Cerbo GX, and MultiPlus-II all talk to each other via VE.Can and the VRM app gives you remote monitoring from your phone anywhere in the world. DVCC (Distributed Voltage and Current Control) is the critical setting — with LiFePO4 you must set the charge voltage limit to 14.2V maximum or you will shorten your battery life significantly.
Pricing in SA (2025): R22,000–R28,000 depending on brand and supplier. Get at least 3 quotes — pricing varies significantly between installers and online suppliers.
My setup: 165Ah LiFePO4 battery, 367W solar panel, Victron SmartSolar MPPT 100/30 controller, and a Redarc BCDC1225D for DC-DC charging from the alternator. Total investment: R32,000 all-in. It powers a Engel MR040 fridge 24/7 and runs LED lights, phone charging, and a 12V air compressor without any issues.
Common mistakes to avoid: Undersized cables — voltage drop kills efficiency. Use the wire sizing calculators available online.
Happy to share my wiring diagram or go into more detail on any component. This stuff seems complicated but it really is not once you understand the basics.
3 Replies
On the alternator damage question — it is a real risk with large lithium banks if you do not manage the charge rate. A DC-DC charger (Redarc BCDC or Victron Orion) limits the current drawn from the alternator to a safe level. This is not optional if you have more than 100Ah of lithium connected to your starting circuit.
— hannes_strydom
On the alternator damage question — it is a real risk with large lithium banks if you do not manage the charge rate. A DC-DC charger (Redarc BCDC or Victron Orion) limits the current drawn from the alternator to a safe level. This is not optional if you have more than 100Ah of lithium connected to your starting circuit.
On the alternator damage question — it is a real risk with large lithium banks if you do not manage the charge rate. A DC-DC charger (Redarc BCDC or Victron Orion) limits the current drawn from the alternator to a safe level. This is not optional if you have more than 100Ah of lithium connected to your starting circuit.
On the alternator damage question — it is a real risk with large lithium banks if you do not manage the charge rate. A DC-DC charger (Redarc BCDC or Victron Orion) limits the current drawn from the alternator to a safe level. This is not optional if you have more than 100Ah of lithium connected to your starting circuit.