What is the minimum solar power that bluetti recommends?
My battery was on charge in the garden all day, when I got home it was at 73% SoC. When the sun went down I brought it inside with 72%, where did the 1% go?
I’m assuming the BMS uses some power but how much exactly does the BMS use while connected to solar panels only?
Hi @Marren2016, This does indeed seem quite unusual.
Could you please tell us the specifications and model of your solar panel? We will then investigate further.
We believe that the actual solar input is very low, so low that it can hardly sustain the self-consumption. Could you inform us of the specific PV input power? This may be related to the conversion rate of the solar panel or the lighting conditions.
Kindly notice some factors that affect the rate of charging when using solar panels.
a. The amount of sunlight
b. The conversion rate of solar panels
c. The angle you place the solar panel
d. The length of the solar cable
Additionally, we would like to know if the AC180 is connected to any load or if the AC/DC output is turned on. We recommend that you disconnect the load and turn off the AC/DC output before trying again.
I have attached a picture of the panels in my garden.
It lost its 1% power as the sun was setting. This is a SSE facing fence so the sun was almost gone when I brought the ac180 into the house.
The panels a 195w each.
The way they are situated in the garden isn’t ideal but I’m getting half a kilowatt charge if I leave the battery out when I’m at work. It’s enough to make tea and toast each day.
So, what is the lowest amount of solar charge to receive before the BMS starts draining the battery? 7w? 15w?
Self consumption is somewhat variable. The amount, can be affected by ambient temperature, State of Charge (SoC) and if the AC or DC loads are on even without a load plugged in. Back drain should not be an issue with good panels, plus I think the internal MPPT should be diode protected for this anyway. (@BLUETTI might confirm this point)
Whether solar is connected or not after solar stops producing, the AC180, if left turned on, will start to drain due to internal parasitic loads.
My caravan power source is a combined AC, DC & MPPT charger, not Bluetti. With loads turned off, but the unit on it draws 250mAh, so over a 24 hour period the battery loses 6Ah (3%). I normally turn the batteries off when in storage to prevent this loss. In your instance the only way to stop parasitic loss is to turn the AC180 off as soon as solar charge ceases. A 1% drop is negligible as, at the last point of charging battery voltage is higher than when at rest.
1 Like
BLUETTI’s internal MPPT has a diode protection feature that protects against reverse connection protection and prevents reverse current flow.
1 Like
So how many watts is the minimum charge before before it’s a waste of time?
Even when the display says 0w input the power led stays illuminated when connected to the panels.
I’m going to assume it’s 10w with AC & DC off because of the BMS and Bluetooth functions. If this is incorrect can you please advise.
Hi @Marren2016, The AC180 has a self-consumption of 5.5W per hour in standby mode.
When DC output is turned on, the self-consumption increases to 6W.
When AC output is turned on, the self-consumption rises to 14W.
When both AC and DC outputs are turned on simultaneously, the self-consumption is 15W.
Therefore, we recommend that you turn off the AC/DC output when not in use. If the solar input of your AC180 is too low to offset the self-consumption, please check if there is an issue with the solar panel and determine the actual input. Could you provide the specific model and specifications of the solar panel so that we can investigate potential issues with the panel itself?
By the way, please note that if you need my assistance, please @BLUETTI_CARE, otherwise, I might not see your message and be able to help you promptly.
1 Like
Hello, here is a link to the panels in question:
I don’t think there is anything wrong with the panels, they put 50% charge into the bluetti in a few hours. I think it was the self consumption + 3c temps that affected the 1% loss.
I’m gonna use 10w as the cutoff for charging via solar. I rarely power devices while solar charging. I move the battery into the garden and keep it in a cooler box for protection from the elements.
Hi @Marren2016, After clicking the link, we noticed that this solar panel does not specify the open-circuit voltage and only shows a voltage of 12V, which is somewhat low. From the image, it appears you have two solar panels. Are they connected in series?
If the display shows 0W input, it means the solar energy is insufficient for charging. This could be related to weather conditions, connection methods, placement angles, or issues with the solar panels themselves.
Please click on the PV input icon during solar charging to check the specific input voltage and current. We will then proceed with further troubleshooting.
