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006-0007207 MPC-1250DC Guide
Rev F
27 of 44
03/03/2022
Section IV
Constant Current Model
Overview
The MPC‑1250 Family offers a model designed to charge lead‑acid batteries used in 28 V vehicle
power applications. This model acts as a current source when overloaded, rather than going
into a hiccup mode like the other MPC‑1250 models. Hiccup mode allows other MPC‑1250
models to deliver higher peak power, while constant current mode allows for battery charging.
The Constant Current model is designed to be connected directly to the terminals of a lead‑acid
battery. It will use the battery to ride through AC/DC source switch overs, and through load
transients. The Constant Current model may shut down during these transients if a battery is
not connected.
Lead‑acid batteries use a Constant Current Constant Voltage charging profile (CCCV). The
MPC‑1250/C model has the following features to facilitate CCCV charging for a variety of different
lead‑acid batteries:
• Fixed 47 A charging current
• User adjustable nominal output voltage (Vset). Range is 22‑33 V
• User adjustable “top off” voltage (Vtop). Range is Vset – 33 V
• User adjustable “top off” time (Ttop). Range is 0‑ 48 hours
User Settable Parameters – CCCV charging
Constant Current Constant Voltage Charging Overview
Lead‑acid batteries charge with a Constant Current Constant Voltage charging profile, as shown
in the figure below.
47A
Vset
Vtop
Ttop
Voltage
Stage 1:
Stage 2:
Stage 3:
Charge Complete