When a DIY solar owner added up a week of power production and use, the numbers suggested that they should see a big boost in battery charging. Instead, the battery bank's average charge rose only modestly, raising a familiar question for anyone trying to maximize a solar setup: Where did the energy go?
As users in a Reddit thread pointed out, the missing power may not have disappeared. It may have been quietly consumed by inverter overhead and hard-to-track loads.
Here's what to know
Across seven days, the original poster recorded 8.4 kilowatt-hours of solar production and just 1.2 kWh of logged use, leaving a 7.2 kWh difference. With six batteries totaling 30,720 watt-hours of capacity, that difference seemed large enough to significantly raise the battery charge.
However, the numbers indicated otherwise: the battery charge increased only 11%, from 33% to 44%.
Confused as to where the extra power had gone, the homeowner turned to the r/solar Reddit community for answers.
In response, several commenters suggested that the power might not have disappeared at all. Instead, it could have been consumed by inverters and other overhead.
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"Are you sure your usage includes inverter overhead?" asked one Redditor.
Other users questioned the measurements themselves, specifically whether the system was capturing small loads accurately.
"Most of the cheap BMSes can't detect currents under 0.5A," said one commenter, suggesting that low but continuous usage might not show up clearly.
The original poster seemed to share that concern, writing: "That's a really good question about the 0W. That number always seems a little suspect."
More background
A steady 30-watt load may sound minor, but stretched over 168 hours it totals about 5 kWh, which could account for the "missing" electricity. In a small off-grid setup, that kind of constant drain can meaningfully reduce how much energy reaches battery storage.
Additionally, the OP explained that government regulations prevented them from installing a larger solar array. As a result, the OP's system has an unusually large battery capacity compared with the solar panels' production capacity.
This cap on solar power generation means that continuous loads will have a larger impact than they would on arrays with a larger capacity. If solar input cannot be expanded, equipment that stays on all the time—such as an inverter or a Starlink connection—can consume a sizable share of available power, especially when the monitoring system doesn't reliably catch low-level demand.
What can be done?
As next steps, commenters urged the OP to verify that inverter idle draw is included in the usage total, confirm that every load is routed correctly through the shunt, and compare the battery-management system's readings with those from a separate monitor.
Commenters also suggested ways to cut conversion losses during periods of light use. One commenter recommended powering Starlink directly via DC and letting the larger inverter rest when it is not needed. Another suggested using a smaller inverter and MPPT setup when the owner is away, then switching back to the larger system during active use.
Where can I learn more?
These articles cover solar bills, expected surpluses, battery payback rules, EV-ready setups, and home backup use.
• In South Carolina, a homeowner saw solar app exports before a $150 bill arrived.
• In Massachusetts, one household says solar and mini-splits should leave 4,100 kWh unused.
• Across 20 states, net metering rules still shape whether home batteries pay off.
• One homeowner found an EV charger and solar worked fine without adding a battery.
• Solar owners say full-home battery backups can make outages fade into the background.
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