Review of TF03 Battery Monitor (#11)
This monitor cost NZ$78 and took 12 days to arrive from China. It was tested by connecting its shunt in series with my existing Votronic shunt, enabling the two different monitors to be directly compared.
This was quick and easy. The Shunt bolted directly to the Battery negative terminal and a single wire needed to be run from the Shunt unit to the battery Positive. A five-way plug-in cable (supplied) then connected the Shunt to the Meter readout unit.
As with most battery monitors, the battery capacity (in AmpHours) needed to be entered.
After fully charging the battery, the capacity% readout was set to 100%. This was accomplished by a single key depression. Again, quick and easy.
There is an audible "Low Battery" alarm that can be set to any desired Ah level.
Don't know your battery capacity? Plug a couple of 230v lightbulbs into your inverter and turn it on. This will discharge the battery until the Inverter hits its "low voltage cutout" point and switches itself off. Then set the meter to 0% (a single key depression) and charge the battery. When the battery is fully charged, read its Ah capacity off the meter, set the battery capacity to this figure and set the Capacity% to 100%.
. This meter gave the same Volts, Amps, AmpHours and Battery% readings as the Votronic unit. I don't mean about the same, roughly the same or approximately the same. I mean exactly
the same. Meter response was fast and stable with no hint of fluctuating current readings - despite their being updated twice a second. Where the Votronic takes 5 seconds or even more to climb to the correct current reading, the TF03 was pretty much instantaneous. Similarly, when a heavy load is suddenly cut, the Votronic current reading slowly falls step by step to zero while the TF03 reacts straight away. Fluctuating current readings can be an issue with battery monitors but in my opinion the Votronic unit is severely over-damped, to the extent that it is incapable of recording transient peak currents such as you get when the engine first starts.
I particularly liked the TF03s "one button" 100% charge setpoint, and the "one button" 0% charge setpoint made it very easy to measure the battery capacity for accurate calibration of the unit. I particularly liked being able to see all relevant parameters simultaneously, rather than having to page up and down through the 7 Votronic options to find those of particular interest - one at a time.
The meter comes with a 1.5 meter connection cable and this is too short for my install. It will be relatively easy to lengthen, but still. It would be good if the screen had a bit more contrast. There was no manual (!) but this doesn't really matter because all the info you need can be found here :- https://www.aliexpress.com/item/100V-10 ... autifyAB=0
I would have preferred that the display showed only the 5 parameters that are of interest to me, but I guess that is a minor quibble. The ammeter reads to 0.01A which seems like needless accuracy for a battery monitor. The screen backlight flashes constantly if the battery is under charge. Needless and a bit annoying, but at least it can be turned off if you prefer.
The bottom line.
A 100Amp TF03 is $78. A 100Amp Votronic is $270.
A 500Amp TF03 is $96. A 400Amp Votronic is $329.
Ignoring the large price differential, the TF03 meets my requirements better than the Votronic.