Every day we get questions about charging LiFePO4 batteries. We’ve reviewed products that work well with our Battle Born LiFePO4 batteries. To begin the series we will discuss the basics of charging batteries, and the products will be covered in other segments.
Charging a LiFePO4 battery basically means applying an external voltage to drive current from the anode to the cathode of the battery. The charger acts like a pump – pumping current upstream, opposite the normal direction of current flow when the battery discharges. When the charger’s applied voltage is higher than the open circuit battery voltage, then the charging current flows. During this process, the battery open circuit voltage increases, approaching the applied voltage of the charger.
The charger can behave in several different ways during the charging process. First the charger can steadily increase its voltage in order to keep the current flow constant. This is the first stage of the charging process – typically called the “bulk” charging stage. During this stage, the charger adjusts its applied voltage to deliver the maximum current to the battery. For example, a 10 amp charger will deliver its maximum of 10 amps during this bulk charging stage, and the applied voltage will increase up to a maximum voltage, or “bulk voltage.”
Once the bulk voltage is reached, the charger enters a second stage, called the “absorption” charging stage. During absorption, the charger applies a constant voltage, called the “absorption voltage.” As the battery open circuit voltage approaches the absorption voltage, the current flow steadily decreases down to zero.
At this point the battery is fully charged. However, a lead acid battery will rapidly lose charge when the charger is disconnected. So, instead of turning off, the charger enters a third stage called the “float” stage, in which the charger drops to a lower voltage and holds at that voltage. The point of this stage is to keep the battery topped off, and account for the fact that lead acid batteries tend to drain, even when there is no load connected.
These stages combined sequentially form what is commonly called the “charging algorithm.” A battery charger may generally be classified by a charging current (i.e. the max charging current) and a target battery voltage (12 V, 24 V, 36 V, 48 V, etc.). But chargers may also include multiple charging algorithms (typically classified as “AGM,” “SLA,” “Gel,” “Wet,” etc.). A closer look reveals that each algorithm has its own unique parameters, including:
• Bulk voltage
• Absorption voltage
• Absorption time
• Float Voltage
There is a wide variation among values for charging algorithms for lead acid batteries. The bulk and absorption voltages typically vary between 14.0 and 14.8 V, and the float can vary between 13.2 and 13.8 V. The 12 V Battle Born batteries sit comfortably right in the middle of these ranges. We recommend a bulk and absorption voltage of 14.4 V. A float is unnecessary, since li-ion batteries do not leak charge, but a floating voltage under 13.6 V is fine.
Here are a few FAQ videos that talk about charging LiFePO4 batteries.
In this blog series, we will post the results of our tests for a variety of LiFePO4 chargers – including converters, inverter chargers, and solar charge controllers. In each case, we will report on the uniqueness of the charging algorithms for each brand, explore the efficacy of using the factory default settings for charging Battle Born Batteries, and determine what can be done to achieve the optimal settings.
If you have any questions or concerns about charging LiFePO4 batteries, please contact us at any time at (855) 292-2831 or email us at [email protected].
Hello,
Do you sell smaller batteries? I am looking for something in the range of a 50ah, 12V battery.
Do you ship to Vancouver, Canada, and can you supply an estimated shipping cost?
Thank you,
Ming
We will be releasing a 12v 50ah in the next week keep an eye out on our Facebook page and website.
What is the reserve capacity of your batteries? I may not be using the correct term but battery manufacturers often specify the amount of total capacity available before there is significant voltage drop. I know this capacity is typically much better with LiFe batteries – sometimes 90%. Can you provide similar information about your batteries?
Hello Crosby,
Our batteries don’t necessarily have a reserve capacity that is more of a term used with lead acid batteries, but you are able to use a full 100% of the batteries capacity. please give us a call if you have any other questions.
775 221 8897
When charging a smaller ah lithium battery such as a 7 to 9 ah do you use the same settings on a programmable ac/dc power converter as you would on a larger ah lithium battery?
Depends on the chemistry. Best thing to do is contact the mfg of the battery and ask them for the charging parameters.
Could I charge this battery with jumper cables connected to a running car battery?
Bradley,
This is a possiblity as long as you don’t exceed 100ah. If you have anymore questions please feel free to call us 855-292-2831 or email us at [email protected]
Please tell me the optimum AMPERAGE level for charging Battle Born 12v 100ah batteries. Thanks.
Hi there, I will include the criteria of amperage level for our batteries:
100 Amp Continuous Current
200 Amp Surge Current (30 Seconds)
If you have any questions, please let me know. You are welcome to reach us at [email protected] or give us a call at 855.292.2831. Thanks!
Hi
I could be wrong, this is what I learned : problem with a”normal” RV battery charger is,:having a float mode?
Zoltan,
That’s a good questions. Our batteries do not require a float charge. But they can be in float mode as long as the float is around 13.6, it is OK for the batteries to float around that voltage.
We currently use 2 external Alphacell 220 GXL 109AH batteries in serial, connected to an APC Smart-UPS 700. We are looking to replace the 220GXL batteries but keep the APC-UPS. We remove the internal battery from the APC-UPS. Will a LiFePO4 battery work in this instance as a replacement for the Alphacell 220 GXL lead acid batteries? We have to replace about 20 of these batteries.
In some instances we use a single 220 GXL connected to an inverter and a standard marine battery charger. This is then connected to a transfer switch which switches from wall outlet power to inverter power in the event of a power failure. Can the LiFePO4 batteries be charged with a standard marine battery charger ?
Hello Jim,
lithium batteries power 12 volt devices with the proper voltage just as a regular lead acid battery so running devices will not be a problem. Charging Lithium batteries requires a voltage in between 14.2-14.6 volts for bulk/absorption, 13.6 or lower for float and should not have an equalization stage. Typical lead acid chargers can work in some instances but we would have to get the model # for your marine battery charger and check the settings for compatibility. Please give us a call at your earliest convenience so we can go over the details. 855-292-2831
Thank you,
The Pb battery chargers I know of have a fixed absorption time (which may be programmable) BUT it seems that the best way to charge a Li battery is to switch from absorption to float when the charging current reaches a prescribed value, so I have 2 questions: Do you know of any PV powered chargers that can switch from absorption to float using a external signal (logic level input) and if using a constant but programmable absorption time, what is a good time (for a specific voltage)?
Hi Wayne,
The Victron MPPT charge controllers allow you to set the absorption time(and voltage 14.4v) to the desired level. In the case with our lithium batteries its about 20 minutes per battery. You can also set the float voltage to the recommended 13.6v after the absorption time is achieved.
Thank you,
I frequently use my RV in below freezing conditions in the winter. I plan on an inside, normally heated battery location, however, their are times when the battery temp might drop below freezing. I understand that your internal BMS has a low temp disconnect to prevent damaging the cells when charging when the batteries are too cold. Could you elaborate on the process of the disconnect/reconnect if this occurs.. In my application would you advise that I add external charger disconnects to prevent accidental charging, such as from solar panels, until I’m sure the battery warms above freezing? Or will the BMS provide this function?
I have 6 12V 200AH lithium ion batteries, and I was wondering what would be the best way to charge them all at once, and how many Amps and volts my charger would have to put out to charge them in at least 10 hours from being completely depleted.
Hello William,
We don’t make 200AH batteries, so I’m assuming these are another manufacturers batteries. I would check with your battery manufacturer to answer this question for you. I can only speak for our 100AH batteries.
Recently installed my 2 100AH Battleborn Batteries in my RV and programmed my solar and inverter/charger to your recommended specs. In case you missed my earlier post, regarding the low temp disconnect of the internal BMS. My question is weather you recommend I install additional charger disconnects to protect the battery from charging in freezing conditions or is the BMS designed to disconnect and reconnect when temp rises to a safe level. Thanks.
Hello John,
The BMS is programed to handle temperature compensation. No need to add a battery disconnect for charging. When the BMS senses the temperature is below 25 degrees F, it will not let the battery accept a charge. Once the temperature is back up above 25 degrees F, the battery will be able to accept a charge again.
What percent increase in battery life would you expect if your battery were only charged in the range 25-35F vs only charged in the range 35-45F?
James,
The colder the temperatures you are charge in, the less life expectancy you will incur. We don’t have a specific % increase or decrease calculation for these temperatures but around 70F is optimal for maximum life expectancy.
Thank you,
Sorry I forgot to include my name and email on the first comment I sent.
I just received 3 of your 100 ah 12v batteries, do I need to charge them before installing or using them?
If I decide to add another in a few months, are there any special procedures that I need to follow?
Hi Jeff,
We always recommend charging the batteries completely before the initial use. This becomes even more important when connecting batteries in series.
Adding another battery in the future will not be an issue, again just bring all the batteries to a full state of charge before using.
Thank you,
Hello
can I leave my rv plugged into shore power for an extended period of time with out harming the batteries.
Hi Tim,
If you are storing your rv and wish to have it plugged in, we would recommend a float voltage of 13.6 volts. If you have a higher voltage applied in float(such as 14.6) then we would recommend that this be no longer than 3 weeks at a time.
Thanks,
What would be considered the resting voltage of a fully charged Lithium battery, with no load connected? I’m trying to ascertain if my (non-Battleborn) battery has a bad cell, or a bad bms. Thanks~
Hi Laura,
The resting voltage of a fully charged Battle Born Battery is 13.5 to 13.6 volts. You may want to contact the manufacturer of your other lithium battery to see if it is the same per their specs.
Thanks,
Hello,
Can the Battle Born 100ah lithium 12V batteries be charged off of the alternator using a battery isolator? I assume as long as the max output of the alternator does not exceed 100amps of continuous current?
Hi Mark, Yes our batteries can be charged off of the alternator using the Battery Isolator within our Accessories. Give us a call for more information on this, 855.292.2831! Thank you and have a great day.
Hello,
I have a 2018 Toyota Rav4 hybrid, I am considering replacing the original 12v Aux. battery with your Lith. Battery. Or adding a 2nd battery, (yours), wired in parallel or connected to the load and separately connected to the car through say the 12v cigar lighter. I do know not much about the Rav4 hybrid elect. system except that it does not have an Alt. but charges the Aux. battery from the Traction battery. The charge Amp. is low 15 or less. in normal driving it seems to stay at 14.2v.
Would your batteries work under either or both senarios, or what changes should should I make to accomplish either?
Hi Russell,
There are many different factors in play with this system and it will require a phone conversation in order to work out the details.
Please give us a call at 775-622-3448
Thanks,
I have a Magnum hybrid inverter with the ME-BMK. In setting up the BMK, it ask me to set the “charge efficiency factor” from the Battery manufacturer or leave it the in auto default. This setting provides an accurate SOC result.
Hi Terence, you can get the full amount of power out of our batteries compared to lead acid ones. Our charge efficiency factor is 100%. Thanks for your comment!
I am looking at sterling power 30 and 60 amp dc to dc chargers. Advantages or disadvantages to either with your batteries. I have a 2-100ah bank.
Hi John, both are great options but the 60 amp is faster. It would charge the 200 ah bank in a little over 3 hours while the 30 amp would do it in 6 hours. If you have any other questions or want to talk about all things batteries, you can call our team at 855-292-2831. Thanks for reaching out!
I would like to convert my wet cells to a low maintenance battery for my home solar system. I currently have 8 ea 6vdc battery hooked in series for 48vdc. The battery’s are the Trojan L16H-AC w T2 technology
435AmH . My question is what maintenance free will provide the 48vdc and the capacity the 435AmH batteries have in series And can I use my existing inverter/converter/charger system? I am looking for a drop in replacement to my wet cells that will meet my 60amp A/C requirement, thank you.
James from Mojave Ca.
Hi James, please give us a call at 855-292-2831 so we can confirm everything and run through your system. Thanks for reaching out!
If someone hasn’t spoken the obvious. This article was suppose to be talking about charging lifepo4 batteries but it instead talks about lead acid battery charging.
I was hoping to actually get information on charging lifepo4 under various conditions like cold. etc. and how the lifepo4 algorithm is set up.
Hi Corey, thanks for your feedback! If you want to get more information about these various conditions you can give us a call at 855-292-2831 or email us at [email protected] and one of our sales and tech specialists can help you. As for the article, we are currently rewriting these blogs and creating a new FAQ series, so stay tuned for those updates.
without subtitles or text translation of vids they are useless for your deaf customers.
Hi Corey, thank you for bringing this to our attention. We are currently in the process of revamping our FAQ videos so it is certainly something that we will keep in mind throughout.
I hope to use a 12v 100ah battery in my van and intend to use a DC – DC charger. The charging volts are rated for up to 15.3 and the amps are either 25 or 50. Is there an upper limit to the charging amps the battery can handle safely? Would the 50 amp charger be safe?
Hey Ernie! Yes, the 50 amp charger will be safe for it. The upper limit for the charging amps that the battery can handle safely is 14.8 and after that you’d have to adjust the charge so it doesn’t permanently damage the battery.
15.3 volts will destroy your batteries, keep it at 14.4v or below. it’s better to charge your bank at less than 100% for longevity. 14.1 volts would be fine to set it to
If you have a Sterling DC to DC charger (30 amp) For a 6 x100 BB battery bank will it cause damage? I know it will take longer to charge, but want to make sure it won’t damage the batteries. Most of the time if it is warm I will be plugging in at night and the Victron Multiplus 3000 can charge the batteries.
Hi Jason, no damage will occur with the Sterling 30 amp charger on a 6 battery bank, but it will take longer to charge.
I’m so confused. I’m trying to understand the best way to charge a Lifepo4 battery from my alternator. I understand the reasoning for using some type of DC-to-DC charger/converter but …..
I have a lifepo4 with a BMS and trying to charge via alternator in my truck.
I see on your recommended chargers you have the Victron TR-smart DC-to-DC chargers and also the Victron DC-to-DC converter.
So…. If I want to use a converter, how would I manage the charging profile for a lifepo4 for bulk, float, etc.? Does the BMS control that or ?????
The charger has a lifepo4 setting but the converter can only charge at a constant voltage.
What’s best and what do you recommend given you sell both products?
Hi Kevin, there are a few differences between the Victron 12/12 – 30 converter vs the Victron 12/12 – 30 Smart Charger. The 12/12 converter is geared towards the use of a non-smart alternator. This unit has a simple rotary dial that the output voltage can be set to; we recommend 14.4v for Battle Born Batteries. There is no actual charge profile on this unit, and the maximum wire gauge recommended is 10 gauge. The 12/12 Smart Charger is more versatile and works with smart/non-smart alternators. The unit has a three stage charge profile with bulk, absorption, and float. These parameters can be customized for Battle Born Batteries with the use of the Victron Connect App as it’s a Bluetooth enabled device. The maximum recommended wire gauge is 6 gauge for this unit.
For alternator charging, we recommend using the Victron 12/12 – 30 Smart Charger for a number of reasons. This will allow you to set a specific charge profile compatible with our batteries, and will ensure proper charging. These units will regulate the amount of current, and also act as an existing isolator. Since it is Bluetooth enabled, you are also able to see some charging information on the app as well.
The BMS does not regulate incoming current, which is why there is a need for a DC to DC charger to regulate flow of current from the alternator to the batteries. If you have any other questions or concerns, please give us a call at 855-292-2831 or send an email to [email protected].
Smoke and mirrors to distract from the challenges of low temp LFP charging.
The imposition of the 12.2V disconnect for AGM is completely absurd. You explain Peukert, and you are familiar with that dude… you know.. Ohm and his law. You KNOW this is flawed. 12.2V is 50% SoC for a battery that has been sitting at rest for an extended period, typically 24 hours.
You should have discharged to 10.5V and used half the tested capacity.
When you charged the AGM in the freezer, did you use temperature compensation? At the coldest temp, you’d be at almost 16V for a proper absorption charge.
Sure, LFP is a superior chemistry in almost every way, but you don’t need to manufacture misleading data and masquerade it as something scientific to poo poo AGM.
Do better.
Hi Steve,
We believe you are meaning to respond to our white paper blog. You can find the blog here: https://battlebornbatteries.com/lead-is-dead-white-paper-study/
And the white paper study itself here: https://battlebornbatteries.com/wp-content/uploads/2020/10/Lead-is-Dead-Cold-Charging-LFP-vs-Lead-Acid.pdf
We appreciate you bringing up the point of the 12.2V cutoff. It is in fact a higher cutoff, but after reviewing the AGM battery manufacturer’s load voltage versus DOD chart and calling manufacturers for their recommendations, we chose to stick with this cut off to reflect what the average system is programmed with.
This test was meant to demonstrate the functionality of a real world system with AGM versus lithium. We do acknowledge that some customers are aware of temperature and load effects on the AGM battery cutoffs, but a vast majority do not know or do not update their programming to reflect this based on their given circumstances.
You are correct that we could have discharged to 10.5V to find the proper 50% DOD. The issue with this is that this would drastically limit the AGM battery’s life cycles available to the user. We modeled this test as if we were end users wanting to preserve our life cycle count of our batteries. According to research performed by Lifeline, if you discharge your battery to this depth you could stand the risk of reducing your total available life cycles from 1000 to 275 cycles.
In regard to the temperature compensation, we modeled this experiment after a typical customer experience, so temperature compensation was not included, as most customers would not implement this in their own system.
We did not intend to present misleading data, we believe that the LFP chemistry’s performance speaks for itself as to why it is a viable option over AGM. Our team is reviewing our verbiage to make sure we better reflect this. Thank you again for your valuable feedback.
Your manual states… “For your Bulk/Absorption stage, the ideal voltage is between 14.2v-14.6v.” This suggests a fixed voltage, rather than a current limited bulk stage. What is the maximum current I might expect your BB10012 to draw with 14.6V applied (likely when it is fully discharged)?
I’m running with a Progressive Dynamics PD4575LI which always/only outputs a fix 14.6V, and does not apply a proper bulk charging stage.
Please post/share a table or graph of charge current vs. state of charge for fixed charge voltage, such as 14.6V.
Thank you for a solid blog/forum page.
cjn
Chris,
Charging parameters can be a bit tricky at times and vary depending on the charger and how many stages it allows for. In your case, having a constant 14.6V is acceptable for the batteries but the batteries don’t necessarily draw power from your charger, they will accept whatever amount of charge your charger puts into them. As a result of this, we recommend that you do not exceed our 0.5C charging rate requirement. This means that for every 100Ah of your bank, the maximum charge rate should be 50A. Your charger seems to be a 75A charger and if that is the case, it is recommended to use this with a battery bank of 150Ah or higher. Exceeding the 0.5C charge rate can prematurely wear down the life cycles of your battery which is why we recommend staying within this specification. If you have any additional questions please give us a call at 855-292-2831.
Thank you!
Thanks for the info. Turns out that under load the converter output drops down from the no-load 14.6V. One measurement I have is 45A into the battery at 13.85V, but I don’t know the state of charge. Also, in my application there is a 50A circuit breaker between the converter and the battery. I’ll keep an eye out for excess current which trips the breaker.
Another data point… I drained off about 85 Ah (1050 Wh) from a full charge. The battery voltage had dropped to 11.5V with the load switched off.
I then turned on the PD4575LI converter. The initial charge condition was 12.2 V at 58.6 A. At 5 minutes of charging, 13.26 V at 50 A. The 50 A circuit breaker did not trip. Charging completed in about 2 hours with 1150 Wh in. The final charge conditions was 14.65V at 270 mA.
Sound reasonable? Any concerns?
I have a pd4655 liv and a 3210an Epever Tracer for my 100 amp Battleborn. I also have a Tri-metric 2025 -A. Sometimes we use campgrounds where we are hooked up to shore power for a number of nights and other times solar is our only source. If I am using shore power I expect the battery charge to quickly get to 100% and if I get reasonable solar, the battery should reach 100%. I have a 100 watt panel on the roof and another 200 watts in a portable suitcase in case I need it, and for emergencies, a 2000 watt Yamaha inverter generator.
I understand that the best SOC is between 20% and 95% to maximize the life of the battery. What can I do to limit the SOC to those parameters or is this something that is not worth worrying about and the BMS in the battery will take care of it?
Don
Hi Don, thanks for reaching out! Ideally we want our battery to regularly reach a 100% SOC. The reason is we have designed the BMS to employ passive balancing at the top of the charge cycle. This means that the battery needs to regularly hit at least 14.2 volts (100% SOC) in order for the cell modules to balance internally. This will offer a battery that can offer maximum capacity along with even charge and discharge. We wouldn’t have you limit the SOC to these parameters as the battery can be safely discharged to 0% SOC and we regularly want the battery to reach 100% SOC for balancing purposes. If you have any other questions, feel free to give our sales and tech team a call at 855-292-2831 or send them an email to [email protected].
Thank you so much for the content on batteries! It is super helpful to know the inter-workings of the batteries and charging. I have been doing some research on battery restoration and I think this content may help anyone looking into this product for more help – https://bit.ly/3nlQMN8
What are the recommended settings when using Magnum’s ARC50 charge controller?
Battery Type?
Absorb done?
Max Charge rate?
Max Charge Time?
Final Charge Stage?
etc?
Do you have a setup sheet listing all of the various setting for the ARC50 controller?
Hi Jim, thanks for reaching out. Our team suggests the following settings:
Scroll through the menu options until you reach “Setup” then press to select
Scroll through setup options until you see “03 Charger Setup” then press to select this option
Scroll through options until you see” 03C Battery Type” then press to select
You should see “Set Battery Type” then scroll until you come to “CC/CV” then press to select this option
It should now show “Set max charge Amps” and scroll until you reach the appropriate amperage. To figure out the appropriate amperage divide the capacity of your battery bank by 2 (For example if you have a 200Ah bank, select 100A). Once you’ve scrolled to the correct number press this setting to confirm.
It should now read “Set CV Charge Volts” and scroll until it reads 14.4V then press to confirm this.
The screen should now say “Set CV Chg Done Time” then press to select this option
Now it should say “Set CV Chg Done Time”. You will need to scroll to set the appropriate amount of time. To figure this time out we recommend 20-30 min per battery (For example if you have 2 batteries set it for 1 hour). Once it reads the correct time, press to confirm
You should see “Set Max CC/CV Time”, press to go to the next option
It should now read “Set Recharge Volts” and scroll until it reads 13.3V. Press to confirm.
Please let us know if you have any additional questions. Our sales and tech team is more than happy to help as well, if you give them a call at 855-292-2831 they can walk you through the process live as well.
Hi! I have two 100amp 12V battleborn batteries in my van. I moved to the mountains in Colorado and with negative and below freezing temperatures common at night, the batteries have been turning off—rendering my van a large cooler! I read above in response to comments and in the manual that they have the sensor that will shut off the current to the battery when its less than 25 degrees. This happens OFTEN in the winter in CO; what do you recommend to keep the batteries working, warm and functional?
Hi Christine, thanks for reaching out! We are so sorry to hear that this is happening to your rig. You can install a DC light fixture with an incandescent bulb if the compartment is well insulated or use a warming pad to keep the batteries above freezing. You also can consider getting our newest heated battery as well. If you have any other questions please feel free to give us a call at 855-292-2831 or send an email to [email protected].
An earlier question asked if batts should be fully charged before use, and the answer was yes. It’s currently winter and I’ve got my camper covered and stored. If I want to charge them now in my home to verify they are ok when I receive them from BB, what is the suggested way to charge them? Trickle charger or something else?
Hi Jeff, thanks for your comment. With our LiFePO4 batteries, we recommend disconnecting all potential power draws from the battery and letting them sit with a full charge, or at least a 50% charge minimum. On a full charge, our batteries have been proven to last at least a year in proper storage conditions with a 2–3% depletion each month. If left at a half charge, the batteries have the potential to not last as long in storage.
If you are storing your entire system, we recommend the use of a battery guardian to help protect your batteries by disconnecting them from parasitic loads once they reach a voltage of 11.5V. We recommend removing the main battery connections if a disconnect switch is not incorporated in your system since our batteries do not require a trickle charge.
We also are publishing an FAQ blog post on winterizing your batteries later this month, so stay tuned. If you have any additional questions please give our sales and tech team a call at 855-292-2831 and they can walk you through the charging process if necessary. Thanks again and have a great day!