Regulator, charger settings for Firefly batteries?

[foojin]

Awaiting three Firefly 4V 15+ batteries to replace four Trojan T105s. We have a new Beta 38 engine with 130A Delco alternator and external Balmar MC-614 regulator, as well as a ProMariner 1240P 40A charger.

I seem to be getting mixed messages about the setup required by the new batteries.

Is it enough to set the battery type on both the regulator and charger to AGM or are there other settings I should be aware of?

Thanks

[smac999]

That charger has a lot of settings.

The fireflys want 14,4 / 13.4v. So look for the closest. Agm1 looks dead on

The agm on the balmar also looks like 14.4/ 13.4v so it’s also perfect.

[john61ct]

Charge the FF to between 14.2V and 14.6V, 14.4V ideal, with temp compensation of course (CC/Bulk phase) and continue charging until the charging current drops to 1.5A (CV/Absorb phase, time will vary).

You DO NOT need to fully charge the Oasis every cycle in order to maintain the capacity and only need to perform a complete charge cycle when you want to maximize the capacity for the following discharge cycle.

The Oasis does not require a float charge when cycling, ideal is "just stop" like LFP.

But if you need to float: 13.2V is better for longevity than 13.4V, especially for charge sources that may be active for an extended period of time (solar, shore or even an alternator if motoring for a while). 13.4V for an alt on for shorter periods is NP.

Reset to bulk phase: for programmable charging sources, adjust the “reset to bulk phase” to occur if the battery voltage drops below 12.0V for >1 minute

[RickG]

I reached out to Bruce Schwab from Ocean Planet regarding charging Fireflys with Balmar external regulators. He sent the attached document. We have our chargers set to 14.4V bulk and 13.4V float. This has been working well for us cruising full-time. We did a lot of motoring upwind in the Bahamas with out 110amp Balmar alternator and the configuration is pretty conservative.

Cheers, RickG

[foojin]

Thanks all, appreciate the help.