Advice Requested re Conversion to LFP House Bank

[eweb101]

Beta Marine sells the part to convert their alternators to use an external regulator. The part costs $45 and is really easy to install.


They'll also give you the schematic to connect their alternator to any of the Balmar regulators if you ask them for it.

[Garbonz]

What about the oasis carbon foam.

[john61ct]

Please ask a specific question.

Ideally one relevant to the OP, or quote the post you are responding to.

If you are asking a question about a new topic, like

"so what do you people think about Firefly?"

Either post it to an existing Firefly thread, or

start a new one?

[newhaul]

Originally Posted by Garbonz

What about the oasis carbon foam.

what about them ??
Please read the title of the thread and try to make posts directed in the general direction of the op's question in requesting assistance with Lfp ( lifepo4) .

[john61ct]

Originally Posted by Garbonz

What about the oasis carbon foam.

Oh, and welcome to the community 8-)

[jmardiat]

Thanks for the posts giving great advice regarding upgrading my current alternator with an external Balmar MC-614 regulator. That is obviously the first essential step. As far as adding additional charging sources, I'll wait to see how much more I need beyond a solar panel on the dodger and the well regulated alternator, and then add accordingly.

Now for another related question... I currently have a 20 Amp battery charger set up for AGM batteries. With a "drop in" LFP battery, do I need to change that immediately, or can I wait until funding for a new charger/inverter?

[mbartosch]

AGM uses an absorption voltage of 14.4 V (up to 14.7 V) which the majority of LFP users on this forum consider way too high. Even worse, AGM float can be as high as 13.8 V (depending on charger) which would be about what many people here would consider as a decent absorption voltage.
So, no, you should not do this, in my opinion.

[newhaul]

Originally Posted by jmardiat

Thanks for the posts giving great advice regarding upgrading my current alternator with an external Balmar MC-614 regulator. That is obviously the first essential step. As far as adding additional charging sources, I'll wait to see how much more I need beyond a solar panel on the dodger and the well regulated alternator, and then add accordingly.

Now for another related question... I currently have a 20 Amp battery charger set up for AGM batteries. With a "drop in" LFP battery, do I need to change that immediately, or can I wait until funding for a new charger/inverter?

that entirely depends on the charger . Does it have user setable charge profiles?
If it does then setting it to the requisite profile for Lfp it will work if it doesn't have user setable profiles then no it would not be a wise choice.

[john61ct]

The true "drop-ins" also have current limiting internal circuitry that can take the battery offline with no warning.

Going to LFP properly is a very big investment even if you DIY, and requires the owner to make informed decisions.

The whole "drop-in" idea is IMO a marketing falsehood, might be OK for some non-critical land based use cases, but not suitable for many on a boat.

[carlwk3c]

Originally Posted by jmardiat

... If I purchase a “drop in replacement” LFP should I still install a BMS in addition? Should I go with a charger/inverter or separate units? How important is a larger alternator vs drag on the engine?
...

Our Battle Born drop in LFPs each have a built in BMS, so no external BMS is needed, and night just confuse things.
Planning to replace our aging Xantrex inverter/charger with a Victron to get pure sine wave and network with our (Victron) MPPT and battery monitor.
We have a 38HP Yanmar with a 210A Electromaax alternator and smart charge controller. (Conversion pulleys for serpentine belt, necessary for >80A alternator load)
Your alternator will not be able to deliver all the battery will accept in bulk mode, and you should have a controller that senses alternator temperature and controls field current to prevent overheating (the option is to upgrade to a larger alternator to charge faster and reduce required run time for charging).

[jmardiat]

Thanks again for everyone’s input and expertise. As a result, I’ve sorted out my alternator plans and will convert my stock serpentine driven 75 AMP alternator to be controlled from an external Balmar 614 controller.

I will need to upgrade my 20 AMP charger and would like to add an inverter. I’ve been looking at the Xantrex Freedom XC 1000W/50 AMP inverter/charger which seems to be at a good price point.

One question I have about this unit is, can it be configured to charge both the new LFP house bank and the AGM starter battery? The unit can be configured for LFP chemistry but that wouldn’t be ideal for the AGM. Is there an easy solution or do I need to go for a more complex inverter/charger?

Once again, many thanks for your advice and opinions.