The battery warning is the most useful message of the device, as long as it is right. If it appears despite fresh batteries, the problem is not the energy but the path to it.
Real warning: easy to fix
If the device reports weak batteries in normal operation, replace all of them at once with high-quality brand cells. Do not mix old and new cells, that skews the measurement and shortens the runtime of the whole set.
Warning despite fresh batteries
If the message appears right after the change, check the contacts for deposits and a firm fit, as a poor transition looks like an empty cell to the electronics. Very cheap batteries also sag early under load and trigger the warning too soon.
Cold and a permanent warning
In frost batteries deliver less voltage, the warning then appears earlier and disappears again in the warmth, which is normal. If the message persists at room temperature with clean contacts, however, the measuring electronics should be checked.
Frequently asked questions
How long can I keep working after the first warning?
Plan the change immediately. The remaining runtime depends on battery quality and temperature and can be very short in winter.
Does the warning disappear immediately after the change?
Yes, with full cells and clean contacts the message should clear right away. If it stays, follow the quick diagnosis above.
Does ignoring the warning cause harm?
The main risk is a failure in the middle of tipping, and deeply discharged cells are more likely to leak. Better change too early than too late.