By use case
Best battery monitor for a boat
On lead-acid you could read state of charge off the voltage and be roughly right. Lithium holds its voltage almost flat from 90% down to 20%, so voltage tells you nothing until it is telling you something urgent. A shunt-based monitor counts the amps in and out. Without one you are not managing a bank, you are hoping — and on a five-figure bank that is a strange economy.
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Selection criteria and compatibility
- A shunt, on the negative, between the bank and everything else.
- A rating above your largest possible current, which is usually the inverter.
- A display you will actually look at — phone or panel, but pick honestly.
- Calibration at install and again after the first full charge, or the reading drifts.
The mistake to avoid
Putting the shunt in the wrong place
If any load or charge source connects to the battery on the shunt's battery side, that current is invisible and every reading afterwards is wrong. The shunt goes on the negative, between the bank and absolutely everything else.
The picks
Recommended options by application
A shunt and Bluetooth with no hole to cut in a bulkhead. The one we would fit on almost any boat.
Where it falls short: You want a physical display you can glance at from the helm.
Full detailThe same shunt with a panel display, for people who want the figure without reaching for a phone.
Where it falls short: You would rather not cut a hole in the bulkhead.
Full detailMarine-documented monitoring that matches the rest of an Enerdrive system.
Where it falls short: You want the cheapest route to a shunt reading.
Full detailIt counts amps correctly, which is most of the job. Fit this rather than fit nothing.
Where it falls short: You need logging you can export, or marine documentation.
Full detailBefore you buy
Confirm battery capacity and equipment compatibility
A recommendation is only worth acting on once you know what the boat needs. The calculator works it out from your own loads in about a minute, and everything above reads differently afterwards.