Electro BC1215 charger query

It changes because the accessories are drawing power from the battery, the modern 3 stage type chargers sense the charge level in the battery and change their charging current accordingly.

Maîneÿ . . .

Hi guys

I've got a BC1220, it has a switch which lets you select "battery charger" or "power supply". From what I've seen, I thought your model may be similar.

Here's the part of the manual that refers-

Power Supply / 2-Stage Charger Mode (see Fig.3)
At this mode the Charger On (5) LED becomes red colour and only Bulk and Float LED will function. The bulk LED will be off
when battery is charged to about 80% full.
The 3-stage charger becomes a 2-stage charger or as power supply in this selected mode because 3-stage charger overcharges
battery with external load.
This selected mode is intended for use to charge battery with external load such as caravan or other battery and external load
combination.
A 2-Stage charger can be used as a combination charger/power supply. An external load can draw current from the charger while
the charger is recharging a battery. The charger does not care how much current is being diverted by an external circuit as it
switches from Bulk mode (constant current ) to Float mode based only on the battery terminal voltage.
However, a 2-Stage charger cannot completely charge the battery when the charger switches from bulk mode to float mode. After
switching to float mode, the battery will, in most cases, be about 80% recharged. The battery receives the remaining recharge
while in float mode over several days.
It is highly recommended to switch back to the 3-Stage Charger Mode periodically when the external load is disconnected.
Also the external load should not be more than 50% of the max. current of the charger, unless the battery is fully charged up. If the
bulk LED is on most of the time then the load is too large.

Hope that helps
Andy.