I’m considering adding some additional LiPo battery storage, which would mean I need to charge at the full Multiplus II limit of 70A DC charging in order to get the whole pack charged within the 6 hour off peak window. Right now I’m set at 50A and my installer suggested that charging below the limit will increase the lifespan of my inverter.
What do people think, will using the full 70A have any significant effect on inverter longevity?
Running any gear constantly at its absolute limits really does take a toll on its lifespan. That’s why these systems should be designed with at least a 20% overhead. That’s how I’ve always done it, and after years of experience in this area, I’ve never had any issues. Also, just to note, the MP2 built to dial back its power (charging current) if it gets too hot that’s baked into the design. If I were you, I wouldn’t stress about charging times. Leave everything as is, just add a battery, and you won’t be late for anything. The cycle will just run a bit longer, that’s all.
The higher the charging current, the less efficient the device becomes, generating proportionately more heat.
Thank you, that’s helpful.
My calculation is that I need to get 90% of the pack charged within 6 hours (which is our fixed cheap electricity rate window), then use most of the pack during the peak day. I could probably get away with running the Multiplus-II at around 60A for charging the pack fully, so some way off the 20% headroom you suggested.
Perhaps I could programmatically throttle that back a bit based on battery SOC at end of day though, as I won’t necessarily always deplete the battery each cycle. Sounds like the Multiplus II will already throttle back if the temps are too high.
Thanks!