© Swiss Bob 2025
Four months on
So far I am very pleased with it. No alarms, no problems and good customer service from both sales and technical support. I’m not saying other vendors aren’t as good but Pecron for example is known for having no support at all. The only minor negative is the cooling fan, when it’s running it’s a little noisy.
I had no problem returning a portable solar panel I decided wasn’t any use in a home backup setup (would be fine for camping) and on the technical side I’ve been impressed that the system is designed to maximise the solar input. From the manual:
The AC300+B300 supports two PV inputs. Each individual input supports up to 12A and the charging voltage should be between 12-150V. The AC300+B300 can achieve a combined maximum of 2400W of total solar input.
There are two configuration options for panels on a string. Series and Parallel. Series you add up the voltages, parallel you add up the amps (IIRC).
My panels are 12.94 amps x 31.30 Volts = 405 watts and based on that it would initially appear that I could only run two panels per string and even then I’d be exceeding the current (amps) input limit of 12 amps, however before buying the panels I called Bluetti technical support and asked about the 12 amp limit. No sucking of teeth, or “I wouldn’t recommend that”, instead the reply was “It’ll be fine”. I am paraphrasing. I thought I’d asked by email but have no record of it so it must have been by telephone. Do your own research.
Initially I was only going to connect two panels per string for a total of 1620 watts maximum power input but as I was setting everything up more permanently and thinking about Winter I decided I might want to use the spare panels and make it three panels per sting even though that would take me 30 watts over the limit of 2400 watts. No problem came back the reply from Bluetti. The important number is the charging voltage, 12-150V. At 3 x 31.30 volts I’m fine and I guess I could add another panel to really maximise Winter power generation and still be fine but would check with Bluetti first. The last is incorrect. You have to use the VoC (open circuit voltage), which is 37.25V plus or minus 3V, it’s the plus or minus 3V which means four panels would be seriously unwise. Always do your own research.
NB All panels on a string should be identical and at the same angle and orientation. The power generated will depend on the panel with the weakest output so if one is in shade/partial shade it will significantly reduce the power from the whole string of panels.
Am I saving any money
£30/month, that’s what I use in my living room, a pound a day. May’s bill was less than £70 but I was still using some heating and I read the meters on the 27th. also bear in mind I have an electric immersion heater.
I also have an uninterruptible power supply and emergency power for when the grid goes out. Speaking of which the standing charge rise from 15p to 60p a day might have been spent on grid infrastructure as I haven’t had a power outage in a while but that’s probably more down to luck than actually spending the increase on anything but trebles all round. I’m happy that it’s a decent investment and allied with a £300 3000w inverter/generator I will survive the apocalypse for a few days longer than most.
© Swiss Bob 2025
