Solar charging lithium battery

[kootenayken]

I replaced my 100 ah AGM with a 100 ah Lithium Iron Phosphate battery. Just wondering why the charger needs to charge at 14.4 v and the solar controller is set to >13.4 v. I only have a 100 watt panel connected and it never gets higher than 13.7 v. Am I going to damage the battery long term by doing a lot of solar charging or should I use the generator and charger to charge the battery?

[richard5933]

What type of solar charge controller are you using? Make/model?

Or, are you just using what was built into the solar panels?

[kootenayken]

I have a Bogart Engineering RV 2030 Battery Monitor and SC 2030 controller.

[uncle_bob]

Hi

Solar charge controllers built for lead acid batteries and done differently for lithiums. The same is true of converter chargers. If you go from lead acid batteries to lithiums, you need to change both the solar controller and the converter / charger.

Some newer devices are built so they can be programmed to run with lead acid *or* lithium. That's great, but it's only true of the devices you might buy if you just converted to lithium. Since these devices are more expensive, they aren't what you would put in if lead acid was the only battery involved.

So, simple answer: replace the converter charger with one that will properly handle lithium. Also replace the solar controller with one that is lithium compatible when you go from lead acid to lithium.

Once you have a lithium compatible device, check the manual to be sure that it is set up for lithium batteries. This may be done with a switch, a jumper, a cell phone, or a dedicated programming "dongle" attached to a PC.

Bob

[richard5933]

I'd contact the folks at Bogart Engineering after the holiday. Their documentation claims that the charge controller is compatible with lithium batteries, but it doesn't seem to include instructions for making that happen. They say to contact them about the details. My guess is that there is an adjustment somewhere in the unit to make it output the correct voltage for your batteries.

[kootenayken]

I added the Bogart Engineering battery monitor w/shunt and their solar controller about 4yrs ago when I added a 100 watt solar panel to help with charging the AGM battery. I choose them with future lithium batteries in mind because the solar controller was already to handle sealed, agm, gel and lithium. When I got the lithium battery I went with lithium setup from their website and made about 8 setting changes including turning off float charging and overcharge % and setting 14.4 for the Absorb Volts. I guess if I am concerned about the lower voltage range of 13.6 v produced by the 100 w solar panel is to add another 100 w panel to the trailer.

[richard5933]

Originally Posted by kootenayken

I added the Bogart Engineering battery monitor w/shunt and their solar controller about 4yrs ago when I added a 100 watt solar panel to help with charging the AGM battery. I choose them with future lithium batteries in mind because the solar controller was already to handle sealed, agm, gel and lithium. When I got the lithium battery I went with lithium setup from their website and made about 8 setting changes including turning off float charging and overcharge % and setting 14.4 for the Absorb Volts. I guess if I am concerned about the lower voltage range of 13.6 v produced by the 100 w solar panel is to add another 100 w panel to the trailer.

What's the maximum voltage that your solar panel can produce? If it's not above the voltage you need, then adding another in series will possibly help. If you add another in parallel, you'll double the amps but the volts will stay the same.

[kootenayken]

Crystalline Solar Panel Maximum power output: 100 watts and 5.8 Amps under ideal conditions. 100/5.8 =17.25 volts. Not sure why I am @ 13.6 v, I will have to pay closer attention to what the peak performance is at high noon.

[Martee]

The SC2030 Controller by Bogart Engineering is designed to auto detect your battery type, including Lithium Batteries. I looked carefully for a manual setup for battery type in the product support and operators manual, but no such discussion. Your Bogart controller does allow for significant expansion, up to 360watts of solar capability.

[uncle_bob]

Originally Posted by Martee

The SC2030 Controller by Bogart Engineering is designed to auto detect your battery type, including Lithium Batteries. I looked carefully for a manual setup for battery type in the product support and operators manual, but no such discussion. Your Bogart controller does allow for significant expansion, up to 360watts of solar capability.

Hi

With many of these "auto detect" gizmos, they do it once when first fired up. They then store the result. If lead acids are upgraded to lithiums, there may be some rock and roll involved to get this or that to figure out there has been a change.

Bob

[drbrick]

A fully charged lithium battery on float is 13.4-13.6 volts .... max charge current 14.4 volts Basically, what every your charge voltage is, the controller is design to allow max voltage charge of 14.4. So I would think what you have is normal.

[JohnTF]

EVERYONE is leaving out the 1st , number one thing !!

Give details about your battery , make model ect.

This is a combination of general info & some specific .

Any battery chemistry has a specific voltage , even lead based batteries vary from FLA - Flooded Lead Acid , AGM - Absorbed Glass Mat , GEL - the electrolyte is a Gel - voltages vary between these 3 lead chemistries .

Lithium batteries have 6 different chemistries , and those 6 chemistries vary .

With lithium --- Generally speaking most multi-cell batteries have inside a BMS = Battery Management System - this controls many things , charging , over voltage , under voltage , rate of discharge .
And again the 6 chemistries vary in their voltages / charging / discharging .
Most of the time they are rated by nonimal voltage , example 1 type should never go below 3.2 volts per cell , then never be charged more than 4.2 .

Moderating any voltage , in any chemistry is best for longer battery life , example a FLA / Deep cycle battery is spouse to be able to discharge to 80% discharge , but for long life --- never discharge more than 50% [ my last battery back in solar system , running air conditioning , lasted 13 yrs. ] ,

Some individual lithium cells [ like 18650 ] sold individually for like electronic cigarettes have little chips / BMS under the positive cap .

So that is what every post is not doing , WRONG , what battery are you dealing with !!!

https://batteryuniversity.com/

[ROBERT CROSS]

Need & required?
I don't 'need' a special solar charger to maintain our BB's. 👍
Our Zamp portables,(360w) have done fine charging thru the 7-pin using the built-in controllers.
The Boondocker 'lithium' converter will synchronize them at 14.4v as needed.
Our eco-usage does not require solar equalization.

Disclaimer...we recently did 16 daze on solar alone, well pleased, never below 12.8v.

Bob
🇺🇸

[uncle_bob]

Originally Posted by drbrick

A fully charged lithium battery on float is 13.4-13.6 volts .... max charge current 14.4 volts Basically, what every your charge voltage is, the controller is design to allow max voltage charge of 14.4. So I would think what you have is normal.

Hi

Roughly 99.999% of all "Lithium" batteries sold into 12V RV drop in replacement applications are LiFePO4 batteries. There are a number of good reasons for that. They also have built in BMS setups, there's also a number of good reasons for doing that.

In order to get the BMS into "equalize" mode, you take the BMS up to the 14.4 to 14.6V range. If you don't do this, the typical unit never goes into equalization mode. This is not a good thing. Again, this is just "the way it works". There are lots of other ways you could go if you design a BMS yourself from scratch.

The "best practice" approach is to take the battery up to 14.5 or so and keep it there until the current drops below some threshold. What that is varies a bit. In an RV where the charger only "knows" about total current, the threshold may be fairly high. Often a timer is used on RV setups for this reason.

Once the equalization is done, the charge source should drop back to something around 13.5V. That keeps the battery topped up, but does not unduly strain the battery or BMS.

Bob

[Martee]

When my AGM batteries need replacement in about two years, I will be upgrading the entire Airstream to four (4) 100Ah Lithium batteries, along with the required controller.

Anybody consider supplementing the Airstream Lithium capacity with additional batteries placed in back of the tow vehicle. The tow vehicle lithium batteries could be connected any time when needed.

https://foxrvtravel.com/ten-lithium-..._source=RVLIFE

[kootenayken]

Battery Specs, 12v Lithium Iron Phosphate Battery w/BMS, 100AH, Internal Resistance 20 mOhms, Charge Voltage 14.6v, Max Charge Current 100A and Discharge Current Temperature -4F to 60F. One big change with the lithium battery is the tankless hot water heater. Most of the time it would not fire up on the AGM battery, it worked fine when we were on plugged in or using the generator. On the new battery it works just fine all the time. I was watching the voltage from the solar panel yesterday and it did get as high as 15.9v and the battery was back up to 14.0 volts by that time.

[FalkTheHawk]

I have done several of the LA -> Lion swap-outs. Sounds like your PV panel voltage may be too low. Also your tow vehicle (TV) voltage from the engine LA will now be too low to charge the higher voltage Lion. What I do is use the Victron Dc/Dc Charger (Renogy makes one too). It has a Lion setting or you can manually program the charge voltages. This will boost your panel voltage to charge the Lion. As a side benefit, if you put a relay on the TV charge line, the same charger can be used to charge your new Lion from The TV. The charger will also protect the TV battery as well by shutting off the charge when the TV engine is off, there preventing draining the LA battery. Without it the TV may not start if you’ve been boondocking several days.

[uncle_bob]

Originally Posted by Martee

When my AGM batteries need replacement in about two years, I will be upgrading the entire Airstream to four (4) 100Ah Lithium batteries, along with the required controller.

Anybody consider supplementing the Airstream Lithium capacity with additional batteries placed in back of the tow vehicle. The tow vehicle lithium batteries could be connected any time when needed.

https://foxrvtravel.com/ten-lithium-..._source=RVLIFE

Hi

If you have a battery bank, ( = all batteries connected together ), you need to be very careful about hooking more batteries into that bank. If you don't do it just right, pretty crazy currents get going. That's generally not a good thing.

Bob

[billtrev]

This was the answer posted by Bogart Engineering on another forum to a question of using the SC-2030 for LiFePO4 batteries


" No, you don't need a new charger. If the charger is used by itself (no TM-2030 connected), then use the AGM jumper settings. Our AGM profile is absorb @ 14.3 V & float @ 13.2 V.

If you have a TM-2030 & SC-2030 connected, set P1 to 14.4V, P2 to 2%, P3 to battery bank capacity in Ah, P10 to 98%, P14 to 0.3 hrs, P15 & P16 to 12.8 to 13.2 V, P20 & P21 Off or 0.00"




I have a TM-2030 & SC-2030 installed an plan on installing LIFePO4 batteries later this summer...

[TinkersToy]

Originally Posted by kootenayken

I replaced my 100 ah AGM with a 100 ah Lithium Iron Phosphate battery. Just wondering why the charger needs to charge at 14.4 v and the solar controller is set to >13.4 v. I only have a 100 watt panel connected and it never gets higher than 13.7 v. Am I going to damage the battery long term by doing a lot of solar charging or should I use the generator and charger to charge the battery?

Just purchase a low cost adjustable controller. I bought my on amazon and have been using it for several years now with no issues. You can adjust for 14.4 and eliminate the float charge which isn't needed for LiIon