These charge times seem crazy

[Bsheffer]

Hey gang...new 2024 Thor Tiburon Sprinter 25 foot....

I recently had my 100 AH lead acid replaced with a 100 AH Battleborn Lithium. Not a cheap battery. Usage capacity and decreased charge time was the goal.

In the end, I am nowhere near the charge time decrease I expected. I ran a bunch of experiments and regardless if I charge the battery from the 3000 watt ONAN generator or plugged into 220 power, it would take at least 3 hours to fully charge the battery from 10%.

When I look at my power control panel, it shows the amount of power going in or out of the battery. Depending on the starting capacity of the battery(And I ran tests at 95%, 60%, 35%, The input wattage I saw was 77 to 477 watts.

From what I could tell, due to be very overcast, I was NOT getting any charge from the solar panels.

Obviously I could be missing something and maybe my exceptions are way out of line but I would have envision a full charge in for instance an hour.....at the most. The wildcard is I have a little bit of concern about the dealer install. A couple screws that held the LCD control panel were just laying out and when I went into the electric panel configuration, the charge profile of the battery was still set to AGM. Obviously I changed that to Lithium and is reflected in the tests as discussed above....

So I guess the question is.....if you have what seems to be a somewhat standard 100 Ah Lithium Battery, how long does it take to charge and from what source?

[SLOweather]

Th4ere are too many unknowns here.


How many watts of solar panels?


What kind of charge controller?


What converter or inverter is charging the batteries on shore or generator power?


Are the solar controller and inverter or converter set to LiFePO after the battery change?




Do you have a battery monitor like a Victron or similar, rather than relying on 4 LEDs on a control panel?


To answer one of your questions, my Xantrex Freedom 2000 X/C inverter charger on 4KW generator or 30 amp shore power will dump 100 amps into the 2 100AH Battleborns.


Sorry, I've forgotten the specs on my 2 residential panels in series and the Renogy MPPT charge controller. I'll see what I remember...

[Bsheffer]

Sloweather, thanks for the input. Of course, all good questions about the equipment. For now, I am just trying to see if I am in “range”. As opposed to your 100 amp delivery, I am looking at more like 10-30 amps, dependent on battery charge, which is a direct read off my panel. I gotta hit the dealer for their i put before I try to get in the weeds on this one. Thanks

[d23haynes57]

Why would you think changing battery brand would make it charge faster? Still power in and power out. What size is your converter/Inverter/Charger? Typically a battery charging system even for Lithium would be sized to be at a 4 hour rate. Lead Acid you want 6 to 8.
Lithium can charge faster but as you approach a 2-hour rate you are damaging the battery. Ideally you never go over 14.4 to 14.6 volts.
You probably need a combination of more charging current, which will be limited by your generator and other loads and more battery capacity. So for example, if you need 100 A/H per day, have a 200 A/H bank and you can then charge approaching 100 A/H to restore what is used in an hour. Won't be quite linear as charging slows as you get close to 80%. Now go for a 300 A/H battery and you can almost linear only needing ~ 30% of the available power. This will help to maximize the effectiveness of generator run time.

[TruckinRound]

3 hrs is about right.

3000W generator output/110V = 27.7A, about the same as 30A shore power. The converter changes that to DC amps. At 30A it would take - 3.3 hrs to fully charge a 100Ah battery from zero.

Your LiFePO4 battery probably has a 100A BMS and can accept a much higher charging rate than a lead acid battery, but the charging rate is limited by the converter output (and wire gauge) in your rv.


360W of solar wired for 12V is also 30A. If you had 400W panels with a 30A mppt charge controller you might see that under perfect conditions.

[Bsheffer]

Dennis, I changed batteries as my understanding is that in general Lithium batteries all charge quicker than lead acid. Is that wrong?

[d23haynes57]

I am sorry. I did not realize thar you changed to Lithium from something else. Yes, Lithium's can charge faster but you need the equipment to make that happen. Battle Born and some other brands do charge a premium and many think that there is some magic.
My response does lay out what you can achieve. Let me know if you would like some help getting there. You may P-mail or text.
631-897-0345

[Bsheffer]

Dennis, I am very limited to space and in the end, I can live with what I got as long as I know what I have is performing correctly. From what I am hearing, I am the ballpark. I misspoke in my original quote as my “pole power is 30 amp-110”. The odd thing is that when connected to the pole, I saw no more than half the input vs. what I saw from the generator. Side note, I have 200 watt solar panel but I sort of figured it was out of the picture for this study as it is so overcast.

[Bsheffer]

truckin, thanks for the thoughts as even I can get head around this math. Perfect..

[dvspl]

LIFEPO batteries can accept a higher charger rate than FLA, but the charge rate in your experiment is purely dependent on your converter. What converter do you have and what DC voltage was it charging at? My PD9260 can theoretically charge at 60A DC. That would require about 6A of 120VAC power input to the converter. I typically see about 45A if my battery SOC is low. That would charge your 100AH battery from 10% in about 2 hours. But that will only happen if the converter is outputting 14.4 VDC. If left to it's own "charge wizard" intelligence, it will output 13.6 VDC and charge at about 10A. So which converter you have and how it is set is important.

[SafariBen]

That's in the range. The amps it will take is all dependent on the volts the converter can supply those amps at, so you might be able to bump up the volts with a bigger charger, but if you're reaching 450W up to 80% full, I wouldn't want much more.


That is a lot faster from 10-90% than the lead was, right?

[Bsheffer]

Charging at 13.4-13.5. Volts. I am satisfied that what I have is working fine. I have a 55 amp charger.

I did have a wonderful support guy from battleborn explain something to me that is so simple but makes total sense. If State of charge for instance gets below a certain level in a lead acid battery, the voltage drops and the battery is depleted, the time to charge both batterie types is the same. However, the lithium battery is able to take double the charge in the same time. Hence the statement of charging faster.

[SafariBen]

I don't understand that comparison. Li should be faster, hands down. Lead could take 6-10 hours, if it makes you feel better.


So your charger might put out 55A at 12.0V, which won't charge anything but keep from discharging at least. A larger charger could bring your charge voltage above 14v and that would increase your charge rate.

[SteveJ.]

Originally Posted by TruckinRound

3 hrs is about right.

3000W generator output/110V = 27.7A, about the same as 30A shore power. The converter changes that to DC amps. At 30A it would take - 3.3 hrs to fully charge a 100Ah battery from zero.

Your LiFePO4 battery probably has a 100A BMS and can accept a much higher charging rate than a lead acid battery, but the charging rate is limited by the converter output (and wire gauge) in your rv.


360W of solar wired for 12V is also 30A. If you had 400W panels with a 30A mppt charge controller you might see that under perfect conditions.

12volt is the "nominal" voltage, the real world figure depends on the battery condition and controller settings. Our 2S3P portable solar array is rated at 360 watts. We have never seen a 30 amp input to the lithium batteries(300AH), even with array outputs of over the 360 watt rating that happens when the sun comes out after a cold rain shower.