Chalo said:
john61ct said:
Chalo said:
john61ct said:
That's what DCDC chargers are for.
Sterling is my choice
So, DC-DC converter to charge, and diode protection on the discharge side?
Sorry what is the diode preventing?
And a charger is different from a converter.
I thought you were talking about using a DC-DC converter as an intermediary between a vehicular alternator + voltage regulator and a lithium iron phosphate battery used in place of a lead acid battery.
The Starter batt, which usually remains lead, is hardwired on the engine/alt circuit, which is the input side of the DC charger.
On its output is the House bank, say 1200Ah of LFP. This bank has no direct connection to the engine's circuits, if that is what you mean by
> the vehicle's bus
And in fact the House circuits may be 24V while the Starter side is 12V. Besides converting/ regulating output voltages, ideally CC/CV/Float each user custom adjustable, the DCDC charger's other job is is limiting the House bank's current draw from the alt/VR, IOW
> to keep it from being charged uncontrollably
That House bank may have a single set of power leads used for charge and discharge, or if it has a BMS, charge and discharge may be controlled separately and connect to separate busses.
When the alt is not outputting, there is no current flow in either direction, DCDC charger acts as combiner / isolator, ACR/VSR, no additional diode required.
There could also be a "rough" solar output wired to the Starter side (or wind, shore charger, hydro, fuel cell whatever) in which case the DCDC charger would automatically condition that flow.
Some DCDC chargers include solar controller circuitry, but I personally have not yet seen one I would use, and would put the SC output directly to House, letting Starter get charged by the alt alone.