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newsiTECHBCDC25 DC-DC charger problem resolved
In the last post in the lithium powerbox project, I reported a couple of issues with the DC-DC charger:
https://bkhome.org/news/202004/dc-dc-charger-issues-and-powerbox-improvements.html
I sent an email to iTECHWORLD Service department, reporting two problems:
- The battery-type selector button did not work, it was stuck on "calcium"
- The MPPT regulator was not tracking at the peak power point of the panel
I received a reply from Jason, that has resolved the first issue, number-2 is looked at a bit more today.
Before receiving the reply from Jason, early this morning I thought
it necessary to perform a more thorough test of the DC-DC charger, solar
charging...
Nice sunny day today, last chance as rain forecast over the next
several days. In fact, almost exactly one year ago, on an almost
identical day, mid-winter, sunny, hardly any breeze, ambient 16 degC, I
tested three solar panels, including the Atem Power "250W" panel:
https://bkhome.org/news/201905/measurements-for-three-solar-panels.html
...and recorded a peak power output for the Atem Power panel of 157.2W.
MPPT charging
Early this morning, Friday 1st May, 2020, 9.10am - 9.30am, have
tested charging the iTECHBCDC25 with this same panel. Ambient is 17
degC, irradiance is 820W/m2 -- a year ago it was almost the same,
800W/m2.
As the DC-DC charger is stuck on "calcium" battery type, I used my
Waeco Coolpower 44 battery box, which has a deep cycle 44AH AGM battery,
a closer choice to the calcium charging profile than the lithium
battery. Here is a photo:
As the battery is fully charged, I loaded it down by a 40W globe
running via an inverter. The panel was outputting 20.3V at 4.99A (101W),
and the battery voltage was 14.7V.
I needed to load the battery down a bit more, bring down the battery
voltage, so that the DC-DC charger will think the battery
state-of-charge is low, and will then pull everything it can from the
panel. So I attached my air compressor. Now getting 15.4V at 9.6A (148W) from the panel, battery voltage 12.1V.
Good, but a year ago, I determined the peak power point of the panel to be 16.21V, power output of 157W. So that issue is still there, the iTECHBCDC25 is pulling at a bit off the peak power point.
But, to be 100% certain about this, I really should test for the peak power point at the same time as testing with iTECHBCDC25.
Battery-type
Moving on, the issue of the battery-type button being stuck on "calcium". Here is a photo:
Fast forward to this evening, I read my emails, and here is the reply from Jason:
...riiiight. Tonight, I used the Waeco Coolpower as the "car
battery", connected to the red and black cable of the iTECHBCDC25, and
hey, was able to change to "Lithium" type. Good, but the User Manual
does not state that the "car battery" only has to be connected. Quoting
from the User Manual:
SOLAR INPUT
Once correctly installed, the iTECHBCDC25 has MPPT solar
charging for increased solar efficiency.
Once your solar panel has been connected to the solar
input section of the iTECHBCDC25 the charger will
transfer to solar mode when the vehicle is not running.
The initial default setting is for AGM/GEL batteries.
If you are charging a battery of a different chemistry
simply change the battery type by pressing the battery
type selector button on the front panel of the
iTECHBCDC25.
Once you have selected the new battery type the
iTECHBCDC25 will remain on this battery type until it is
changed.
Solar charging requires a solar input of 16 to 25v.
Your solar panel will need to be unregulated when
connecting to the iTECHBCDC25.
Well, that is a relief, the charger is not broken.
Tags: nomad