DIP switches on Renogy DC-DC chargers

• the DIP configuration tables and nomenclature in the 20-40A-60A DCC1212 series manual are needlessly confusing. The tables below intend to correct that
• the DIP switch area has indicator that shows ON↓. Pay close attention to this, especially if the charger is mounted and you are looking at it from an odd angle.
• in the tables below, lithium (Li) profiles effectively means “floatless” and lead (Pb) means “with Float stage”. It is possible to define a quasi-Float for LiFePO4 using a “lead” profile; see below.

(about these summaries)

An explanation of Floatless charging

There are reasons for and against "floating" lithium.

Renogy Li profiles are charge-and-stop:

1. charge to the selected Boost setpoint
2. stop charging
3. drift down to the reBoost setpoint, typically 13.2v,if loads are present
4. start the charging cycle again

If you want to hold a 13.2v floor instead of cycling repeatedly you might charge use a Pb profile to charge to 14.1v⁶⁾ and “float” at 13.2v. This would let the bank relax to somewhere between ~60-70%,⁷⁾ although with light loads you might not fall to 13.2v until sundown.

A 13.8V float is unacceptably high⁸⁾; it would pin the bank at 100% all day. 13.5v, the last option, may be acceptable if you are running heavier loads. 13.5v will put constant (albeit relatively gentle) charging pressure on the bank. Experiment with it; if it pins SoC at 100% all day then 13.2v might be healthier for the battery.