Question About Upgrading To LiFePO4 Batterries

[Hblick48]

I currently have 300 watts of solar with four 6 volt batteries in series/parallel.

Thinking of upgrading to 2 100Ah LiFePO4 batteries in parallel, giving me the same usable power.

The converter/charger In my rig does not have a LiFePO4 setting.

I am also going to upgrade my MPPT solar charge controller to one that is compatible with the new batteries.

Since the new charge controller will output the necessary voltage for LiFePO4 batteries, is it necessary to upgrade my rigs converter/charger? Both systems are operational when rig is plugged into shore power.

[scottz]

No, your converter will work. However, it will not charge the lithium batteries to 100%; just a little short but I don't know the exact numbers. Several of us have run or are still running lead acid converters with lithium batteries. You can get a little higher charge on your lithium batteries using the Charge Wizzard. My understanding is that not charging lithium's to 100% extends their life.

As long as you have sun, your solar charger will bring them up to 100%.

I had the same question for Progressive Dynamics when I switched to lithium. Here is the response:

Subject: RE: PROGRESSIVEDYN.COM Contact Form

Hello,
It appears that you have a converter built before the lithium select switch was built in.
So you have two options for charging lithium batteries.
The first is to replace your converters circuit board with our lithium converter circuit
board….PD4575LICSV
This can be purchased through our recommended distributor, Leisure Time Distributing.
https://www.ltdrvparts.com/PROGRESSI...THIUM-CHARGER-
SECTION-PD4575LICSV-PD4575LICSV.htm

you can also use the wizard button on your DC fuse board to change the voltage output of your
present converter.
by pressing the button and forcing the boost mode, you will get 14.4 volts out for charging.
The converter will stay at 14.4 for approx 4 hours, which should give you plenty of time for
charging.
You will need to do this every time you need or want to charge…..could be daily, weekly,
depending on how you camp.

I hope this info was helpful
Please let me know what questions/concerns you may have.

The other option is to just forget about it, let the converter charge them as much as possible and let solar top them off.

[Lee-CI]

You will save a good bit of weight going from 4 x 6V batteries to a pair of 100 Ah LiFePO4 batteries. Depending upon the brand you choose, you might consider running a single 200 Ah battery instead for the same or lesser price. While your current converter will only charge the LiFePO4 to about 80%, a MPPT controller for solar charging should be able to top off the batteries so long as you have good sun available and you are not pulling more out of the batteries than your solar can overcome. Be sure to get the entire mfg specs on your LiFePO4 due to needing to set up each parameter correctly in your MPPT controller. Good luck and have fun with your upgrade!

[rames14]

Just curious why you need to change your SCC? Which one do you have and what are you going to?

[Hblick48]

Originally Posted by rames14

Just curious why you need to change your SCC? Which one do you have and what are you going to?

My Renogy SCC is 7 years old and doesn't have an option for Lithium batteries, only gel or flooded.

[Foldbak]

Greetings for Shingle Springs! I recently upgraded to lithium and love it. I only wish I had gone with a single 200 or 300 AH battery instead of two 100 AH's. Lithium is so much cheaper these days. Sodium Ion coming out soon!

[Daryles]

The first upgrade we did was to lithium batteries three years ago. We still have the original FLA converter. I never upgraded that. I use the Charge Wizard button to put it in "BOOST" (14.4vdc) mode when boondocking to get a full charge while running the generator if we have to.
We have 800W of solar panels into a Victron 100/30 MPPT. It is set to lithium and tops them up to 100%.
One of the best things about lithium is, they charge FAST!!!!.
Normally on a sunny day the batteries are full before noon if we are boondocking and not running the generator (full sun, no clouds or shade).

[Hblick48]

And now for the rest of the story:

Before pulling the trigger on Lithium batteries and solar charge controller, I decided to check my existing lead acid golf cart batteries. One pair was dated 1/2017 and the other pair was dated 10/2018, so I was sure they were no good.

I disconnected all of the wiring, and checked each cell with a hydrometer...all tested fine. Did a load test on each battery....all tested OK. Charged each battery with a charger that has a desulfation cycle. Cleaned all the terminals and hooked everything back up.

Maybe next Black Friday will be my time for Lithium. No reason to spend that money now.

[Foldbak]

Originally Posted by Hblick48

And now for the rest of the story:

Before pulling the trigger on Lithium batteries and solar charge controller, I decided to check my existing lead acid golf cart batteries. One pair was dated 1/2017 and the other pair was dated 10/2018, so I was sure they were no good.

I disconnected all of the wiring, and checked each cell with a hydrometer...all tested fine. Did a load test on each battery....all tested OK. Charged each battery with a charger that has a desulfation cycle. Cleaned all the terminals and hooked everything back up.

Maybe next Black Friday will be my time for Lithium. No reason to spend that money now.

That's a good idea especially with the intro of sodium ion batteries. Lithium prices will plummet to compete with SI batteries.


Dam rabbit hole

[JHenry]

Nobody talks about the weight of a sodium based battery. They are as heavy or heavier than lead based batteries and are also quite a bit LESS energy dense than Lithium. If you want a heavier, less energy dense battery you have them already under your hood. Jussayin’.

[AZMont]

I have a 2015 3100RL with a power center that does not accommodate Li-Ion batteries. I solved the problem by installing a pure sign wave inverter / charger with am integrated cut over switch. The inverter charger charges at an 80 amp hour rate and supports Li-Ion batteries. I also have 300W of roof mounted solar and use a Renogy solar controller as well. Solar works fine, but when we dry camp under trees in not always effective in AZ.