Lithium Batteries used for House batteries

[Michael Powell]

What's the good bad and Ugly using lithium for house batteries.  

1 Will they charge off the Alternator/ Inverter/ Generator

any other equipment needed to convert or is it a bad deal...

[JDCrow]

1) No

Generally a newer inverter/charger that is mapped to charge lithium is needed. And a DC/DC charger to charge off alternator.

 

I did convert to lithium, I’m no expert, but can give you what I did 

[Michael Powell]

10 minutes ago, JDCrow said:

1) No

Generally a newer inverter/charger that is mapped to charge lithium is needed. And a DC/DC charger to charge off alternator.

 

I did convert to lithium, I’m no expert, but can give you what I did 

Are you happy with the results.. How many Batteries did you have and how many batteries are you using also cost and where you purchased the system. My e-mail is mpowell@powellwatson.com

 

[Tbrownski]

3 hours ago, Michael Powell said:

What's the good bad and Ugly using lithium for house batteries.  

1 Will they charge off the Alternator/ Inverter/ Generator

any other equipment needed to convert or is it a bad deal...

I have 4 battleborn gc2 100 amp lithium batteries in a 2007 knight and charge them with my magnum inverter charger. I upgraded the control panel to the me-arc, but they make a special lithium one as well I think.
 

My alternator didn’t charge my house batteries before so I didn’t have to worry about it but you could just unhook the solenoid. You need a dc to dc charger or battleborn makes an isolator that replaces your bird solenoid so that your alternator doesn’t overheat charging your house batteries. 
 

I’m relatively new to these but they basically doubled my amp hours since you can run them to 0 instead of 50%. The only downside is that you need to avoid overheating your alternator and they don’t charge under 25 degrees- although if you get the internally heated battleborns as I did you don’t have to worry about it 

[waterskier_1]

I'll provide my experience from recently designing my own LiFePO4 batteries. 

First to keep it generic, some inverters have a setting for Lithium, or better a Custom Setting.  You can check if your Inverter/Battery Charger does by referring to the manual.  This would cover both Shore Power and Generator since the same Inverter/Battery Charger works from either.  

None will properly operate from the alternator without some additional equipment.  This is due to two primary reasons: 1) The alternator puts out 14.2-14.4 volts typically, and constantly.  It is not a smart charger.  This means that your batteries will be constantly charged at 14.2 - 14.4 volts anytime and all the time the main engine is running.  This is not good for any battery, but more damaging to Lithium cells.  I disconnected the alternator from charging my AGMs years ago just for this reason.  I currently don't have plans to have my alternator charge my Lithium batteries, but that could change.  2) more importantly, the Lithium cells can take almost as much current as any of our coaches (as equipped from the factory) can throw at it.  This means that it will accept 150 - 200 Amps from the alternator with no problems.  But the alternator, even if rated that high, is not designed to run at the maximum rating indefinitely.  It requires a duty cycle, to cool off and keep from destroying itself.  This is the issue most people with Lithium worry about.

The answer to charging from the alternator, if desired, is a DC-DC smart charger.  This operates much like your inverter/charger or more closely a Solar Charge Controller (SCC).  It will take the alternator voltage (14.2 -14.4 volts) and convert it to the correct voltage to charge Lithium batteries Buk/Absorption (these are the same in Lithium Charge Algorithms) and then switch to Float (which is really below the nominal Lithium Cell voltage).  This will allow the alternator to safely charge your Lithium batteries.

Now for some background - more specifically about Lithium (LiFePO4) batteries.  First, what are their advantages?  There must be some if you're going to potentially spend good money on a new inverter/charger and a DC-DC Charge Controller which could cost upwards of $2,000.  Add to that the initial high cost (but coming down all the time) of the Lithium Batteries themselves.  Some advantages are: low/no maintenance, higher capacity compared to the same size Flooded Lead Acid (FLA) or AGM battery - almost twice.  This is because you can use almost all the rated capacity (but typically 90% is recommended) versus only 50% for conventional batteries.  The also weigh about 1/2 of what conventional batteries weigh for the same capacity.  These could be important considerations in designing a coach, but not really all that important to us since our coaches already have the weight and size capacity built into them.  The other really important feature is they can be charged at a higher rate without damage.  In fact, most will take the full charge available to about 90% SOC (State Of Charge).  No more waiting hours charging the batteries at 10 - 15 amps after switching to float, which is required by the chemistry of conventional batteries so as not to destroy them.  My Lithium batteries will take my 120 Amps right up to 90+% SOC.  I can't give a more accurate figure because I've not had the installed and used enough yet.  But, in reality, this only really makes a difference if you need to charge them in a short period of time.  If you are hooking up to shore power for the next 24 hours, this point is moot.  So, the real advantage is to us boondockers (dry camping with no electricity).  If you don't have solar, this mean 50% or more reduction in generator run time to recharge.  But if you do have solar, it means that it will use every amp generated to charge the batteries up to 90% SOC, where, with my previous Lifeline AGMs, by mid-day, the SCC (controller) would start limiting the current per the charge algorithm, and never achieve more than 85% SOC. 

Bottom Line: Unless you already have all the proper equipment to charge Lithium, I don't see it as a value solution unless you Boondock for several days or weeks in a row.  Spending a night at Walmart Parking Lot doesn't count.  

There are many considerations to be sorted when choosing a Lithium battery, the most important is Low Temperature Sensing and control.  Most do not have a good Battery Monitor System (BMS), and if there is even the possibility of  exposed to freezing (below 32°F, 0.0°C) it is important.  There are other things to consider regarding buying a Lithium Battery, many which you won't know about.  (A Battery is the container that holds one or more cells, along with control circuitry).  I have built my own, from individual cells, which in themselves have varying properties, and looked at many BMS controllers and battery heating devices.  I have an Electronics Engineer degree, and I used it to dig into the spec's that most wouldn't even know existed.  I can address that later, if there is interest in the subject.

One other point I should clarify.  I said that I disconnect my alternator from charging my AGM house batteries years ago.  I have not needed this because I have 1400 Watts of Solar on the roof, and generator backup, when needed.  I have not found I need to charge while driving, since most of the time I've charged the batteries the night before departing, and the solar can usually provide necessary power while actually driving.  I rarely drive at night.

I'm open to questions, 

  -Rick N.

[Mark B]

Here is how I set up mine. I started by upgrading my inverter from the Zantrex RV2022 to the Freedom 3012 so I could have more charge profile options and a pure sine wave. Then I bought two battleborn batteries on sale to replace my 4 old 6 volt deep cycle lead acid batteries. With some good advice and research I replaced the trickle charger and bidirectional relay with a dc to dc charger and an Amp-L-Start. The dc to dc charger limits the load on the alternator to 30 amps while charging during driving. The Amp-L-Start charges the chassis battery from the house batteries. I the added two more battleborn batteries on sale for a total of 4-100 Amp hours. I also installed 2 355 watt residential solar panels and a Victron 100/50 solar controller. It’s always a work in progress.

[1nolaguy]

I converted to LFP batteries last year. Here is what I learned.

1) LFOs do not play well with modified sine inverters like my old Xantrex Freedom 458. If you have an older modified sine wave inverter you will likely need to replace it with a new pure sine wave model.

2) LFP, if charged from your alternator will need an inline DC to DC converter capable of limiting the amount of amperage. LFP will take as much as you dish out up to about 100 amps. This can play havoc on your chassis battery charging and your alternator. Some folks a add a second high amp altinator to provide charging but unless you are non-sola and spend a lot of time off grid your batteries will likely be fine between shore power connections or on board generator run.

3) LFO have 80-90% usability (some even 100%) so you get a lot more life out of each battery. I replaced 4 - deep cycle lead acid batteries with 2 - SOK 100 amp batteries with greater net available amperage.

4) For really good up to date review of everything LFP check out Will Prowes on Youtube. He does full tear downs of new batteries be has bought and provides all the needed details to make the best selection for the price.

5) Newer "Server Rack" battery systems like the EG4 models have benefits over the more traditional plug and play type 27 or 31 LFP batteries line the Battle Born and SOK 100 amp batteries. Worth looking at. If this was a year ago before I replaced my I/C I would opt for a 24v SR battery system and a 24v to 110 ac I/C. There are benefits to do this even when you add in the cost of of a 24 to 12vdc converter for your 12v system.

I am very pleased with the performance of my SOK's and at $570 delivered, for me, were a better choice than the BB at close to $900 for the same amperage. Were it not for the fact that I had already replaced ny old I/C withe a new 12 to 110 Aimes in March I would change to 24v system but now being 12v I personally think the SOKs are a great way to go. YMMV.

[waterskier_1]

2 minutes ago, 1nolaguy said:

I converted to LFP batteries last year. Here is what I learned.

1) LFOs do not play well with modified sine inverters like my old Xantrex Freedom 458. If you have an older modified sine wave inverter you will likely need to replace it with a new pure sine wave model.

 

 

I'm curious why you say this.  The battery voltage is the same 12 Volt DC as your previous batteries.  I can't imagine how the inverter knows what type of battery you have powering it.   Or, do you mean that the Battery Charge in the older Modified Sine Wave (MSW) Inverter/Chargers is not capable of Charging the newer Lithium batteries?

 

[1nolaguy]

I am not a LFP expert by any measure but based on the research I did prior to going lithium, including talking with the tech support personnel at Xantrex, The issue is with the battery internal BMS circuitry. Those electronic component, as well as some RV electronics like new flat screen computers, house refrigerators and computers can be stressed by modified sine wave current (sometimes referred to as dirty electricity). I do not know this from first hand experience but from what I have gathered from qualified sources.

[waterskier_1]

22 hours ago, 1nolaguy said:

I am not a LFP expert by any measure but based on the research I did prior to going lithium, including talking with the tech support personnel at Xantrex, The issue is with the battery internal BMS circuitry. Those electronic component, as well as some RV electronics like new flat screen computers, house refrigerators and computers can be stressed by modified sine wave current (sometimes referred to as dirty electricity). I do not know this from first hand experience but from what I have gathered from qualified sources.

I find this quite suspicious.  I am not an LFP expert either, but I am an electronics engineer with over 40 years design experience.  I can't really see the correlation between the MSW (Modified Sine Wave) 110 VAC output from an inverter having anything to do with the BMS (Battery Management System) in a Lithium battery.  The BMS performs several functions, like maximum charge control, maximum voltage control, minimum voltage control, and on better units, minimum temp control (both charging and discharging) and cell balancing (both static and dynamic), among other things.  It is not clear whether the claim is that the BMS interferes with the inverter, or that the inverter interferes with the BMS.  I've assisted and advised on many installations, and have never heard such a complaint.  That doesn't mean it can't happen, but it doesn't appear to be a likely occurrence.  Also, many have replaced their MSW inverters with PSW (Pure Sine Wave) as an upgrade along with the lithium battery upgrade, some because their inverter was to old to properly charge lithium batteries, but most because they have read that PSW is the "cat's meow". 
Regarding "dirty electricity", that can be caused by poorly designed MSW inverters, but my experience is it is more likely from fluorescent lights and special switching circuitry - especially that used in cheap LED lights.  I've had LED lighting totally wipe out all navigation systems on boats.  This is due to the way they switch on and off the voltage to the LED to dim it.  I can go into further details if anyone is interested. 
Most house (residential) refrigerators work on MSW.  I haven't seen any report where MSW caused damage.  It can cause problems with overheating in some motors, but, as far as coaches are concerned there are only a few devices that should not be used with MSW.  These include most adjustable electric blankets/throws and  fancy digital coffee makers (specifically Keurig).  I'm sure there are other devices, but these are the most commonly reported.  I am not aware of any studies on which devices work or don't work on MSW, with the exception that Samsung refrigerators are warrantied to work on MSW.  This does not imply that others will not work, only that the manufacturers have not spent the time and money to ensure that they will, considering the small market who cares.

I would not let a MSW inverter whos battery charge has the capability of charging LiFePO4 batteries keep me from installing them.

  -Rick N.  

[Ivylog]

Where to begin from my perspective, also a EE but never worked in that area other than aviation electronics years ago. 
I would not draw Lithiums down to 0 SOC.. 10% left in them will increase the cycles/life. You can discharge Lithiums below freezing, but don’t charge them. IF I need to charge them I’ll put a 120V heater in the compartment to get them above freezing.

Yes a charger that only has a AGM setting will work, but will only charge to approx 90%… same as a alternator.

 Instead of a $$ dc-dc charge controller,  I added a $5 timer to the BigBoy control wire so I can cycle the alternator’s output on-off. I added a remote temp probe on the alternator to get a baseline on its operating temperature. Haven’t finalized what % of the time to let alternator charge.

9 months ago I built 600AH of Lithiums for $1200 plus 10 hours of my time…$2/AH. In October I ordered 8- 280 AH cells for $375 which would make my DIY price less than $1/AH. They have yet to arrive and after filing a dispute with Ali Express, they have refunded my $375. With the current shipping delays, they may still arrive at which point I’ll pay for them.

Below is another to good to be true…a  200AH Lithium battery for $230 but March delivery. There are plenty of 200AH Lithiums on Amazon for $650 delivery in 10 days. Wait 6 months and no telling what the price will be.

I installed 1000W of solar on my 08 Navigator with a 80 A mppt controller for $1200 so topping off will be possible on a sunny day.

 

 

Edited January 2, 2022 by Ivylog

[Windsornut]

 

I am using 8 Battle Born lithium batts. and a Magnum 2812 inverter with auto Gen start adaptor and battery management kit and new control hard wired in house. and Li Bim talked about below to save alternator.  8 batts. can draw 110 or so amps on shore power but seems to be ok for the last year or so.  For my 2002 system conversion I was finally lead to M&M RV Electronics.  They are really good at this older stuff.  Chris is the man!  www.mmrvelectronics.com

The problem on the system can be over taxing the battery charging alternator on the engine while long distance driving.  In my case, the Lithium battery bank for solar panels is so large, it can pull way more energy/amps than the alternator can supply on a single steady charge so, something has to be installed to keep from cooking the alternator and that is an isolator of some sort.  I installed a Li-bim (Lithium battery isolator manager) in place of the old isolator system components.  Basically what it does is allow charging of house Lithiums, chassis lead acid batteries and then gives the alternator a rest (Cooling) these generally operate on a timing system rotating among all 3 stages while you drive. To be clear,  I removed 3 major original pieces, charging 3 wire brick (trickle charge chassis batt. maintainer). (Isolator delay relay delay Diesel) And battery isolator relay.  LiBim replaced battery isolator relay.  My point is: All of these orignal components work well for lead acid or agm batts. Also including shore power charging.  (All components are needed obviously). One more thing, I have found that many of the small black relays on the coach system are the same and available at places like Amazon.  You have to look for small print.  

Hope this helps

[waterskier_1]

5 hours ago, Ivylog said:

Where to begin from my perspective, also a EE but never worked in that area other than aviation electronics years ago. 
I would not draw Lithiums down to 0 SOC.. 10% left in them will increase the cycles/life. You can discharge Lithiums below freezing, but don’t charge them. IF I need to charge them I’ll put a 120V heater in the compartment to get them above freezing.

Yes a charger that only has a AGM setting will work, but will only charge to approx 90%… same as a alternator.

 Instead of a $$ dc-dc charge controller,  I added a $5 timer to the BigBoy control wire so I can cycle the alternator’s output on-off. I added a remote temp probe on the alternator to get a baseline on its operating temperature. Haven’t finalized what % of the time to let alternator charge.

9 months ago I built 600AH of Lithiums for $1200 plus 10 hours of my time…$2/AH. In October I ordered 8- 280 AH cells for $375 which would make my DIY price less than $1/AH. They have yet to arrive and after filing a dispute with Ali Express, they have refunded my $375. With the current shipping delays, they may still arrive at which point I’ll pay for them.

Below is another to good to be true…a  200AH Lithium battery for $230 but March delivery. There are plenty of 200AH Lithiums on Amazon for $650 delivery in 10 days. Wait 6 months and no telling what the price will be.

I installed 1000W of solar on my 08 Navigator with a 80 A mppt controller for $1200 so topping off will be possible on a sunny day.

 

 

Dick, I worked in aviation electronics (mostly weapon systems) back in the early 80’s.

I agree that you should never draw lithium’s down to 0 SCO, and you shouldn’t store them at 100% SOC either.  Depending on the manufacturer, there are different specifications.  When I purchased my batteries, by Lifeline batteries had totally given up and I needed to put a replacement in quickly.  So I decided to go with the best quality cells I could find (yes, from China, no cells are manufactured in the USA for mass distribution).  My cells spec the maximum charge temperature at 0°C, and maximum discharge temperature at -20°C (-4° F).  But this is with the caveat that the batteries are constantly under charge or discharge.  For storage, they allow -20°C (-4°F) for up to a month, but longer term storage should not be above 0°C.  I have not confirmed with the manufacturer that Float charge is considered charging, since there really is no chemical conversion taking place would generate internal heat.  Where I live here in Colorado, it was 2°F this morning and didn’t get above freezing yesterday.  So, yes, you can discharge them below freezing. 

Due to the above temperature limitations, I knew my design would have to have 1) a BMS that had a working low temp cutoff (it’s surprising how many do not), and 2) an internal heater.  I’ve spent too many days and nights draining freezing water and winterizing boats and motorhomes that I don’t want to have to worry about that. 

I will take exception to using your method of cycling the alternator output on-off.  This takes us back to the 1950’s Battery Chargers, where they only run at max output, and you are manually trying to regulate something less (like a 1990’s 3-Stage battery charger).  Those devices (the manufactured ones anyway) are designed only to prevent the alternator from self-destruction due to overheating by supplying huge amounts of current to the lithium cells.  But it does nothing to manage the charge profile of the lithium batteries.  To most, $1000 - $2500 in lithium batteries is more important to manage than a $350 alternator.  But, from an engineering perspective, running down the road with 14.4 volts on the Lithium batteries, even if only 30% of the time, when they are already charged, is bad design.  As I mentioned in a previous post, I didn’t want to subject my AGM batteries to a constant 14.4 volts for 8 hours when they were fully charged, so I had disabled alternator charging of my house batteries years ago.  I don’t miss it.  I have 1400 Watts of solar on the roof, and only travel during the day, so I have never drained my batteries, and they darn well better last more than a day without charging.  From an engineering view, I could not recommend the solution to the general public, even though it may work fine for you.  A no hassle, modern DC-DC Converter is the only way I recommend connecting the alternator to Lithium batteries. 

As I mentioned, I purchased top shelf, A+ rated cells, and also a top rated BMS with dynamic and static load balancing, 150 Amp charge/discharge capability, and a fully functioning high/low cell voltage cutoff, and high/low temperature cutoff, dual temp monitoring, along with other features.  I also designed an internal heater and electronic control for that and have made provisions for cooling, but have not implemented those yet due to the immediate need to install new batteries in my coach.  I purchase a hydraulic crimping tool for 4, and 6 gauge wire, along with new wiring terminals, heat shrink tubing (for 4 & 6 gauge) and other hardware.  My cells require compression to maximum life, so I had to design that too.  I was able to install it all in a conventional Group 27 battery case.  The first battery cost me about $950, but the second was only about $850 due to having purchased some supplies for the first battery in quantities (like I had to purchase a minimum of 3-ft Heat Shrink tubing of each color, but had enough for two batteries, and I only had to purchase the hydraulic crimper).

I have a question on your solar panel picture.  Are the panels tiltable both directions?  My panels on the side opposite the sun (as shown in your picture) are mounted on extended legs to get them above the shadow of the A/C and other vent covers.  I wish all my panels were tiltable, but the panels that came with the coach are not, and are mounted randomly (at right angles to each other) so it would require total removal and reinstallation to make them tiltable.  Let this be a lesson to those installing solar panels.  Instead, I’m just adding more panels that are tiltable.  Most of my dry camping is in the winter, when the sun is low in the sky.  Before these lithium batteries, I had more solar than my AGM batteries could use.  I’ll find out in two weeks how it works with the new 600 A-Hr Lithium batteries.

  Rick N.

2 hours ago, Windsornut said:

 

 

I am using 8 Battle Born lithium batts. and a Magnum 2812 inverter with auto Gen start adaptor and battery management kit and new control hard wired in house. and Li Bim talked about below to save alternator.  8 batts. can draw 110 or so amps on shore power but seems to be ok for the last year or so.  For my 2002 system conversion I was finally lead to M&M RV Electronics.  They are really good at this older stuff.  Chris is the man!  www.mmrvelectronics.com

The problem on the system can be over taxing the battery charging alternator on the engine while long distance driving.  In my case, the Lithium battery bank for solar panels is so large, it can pull way more energy/amps than the alternator can supply on a single steady charge so, something has to be installed to keep from cooking the alternator and that is an isolator of some sort.  I installed a Li-bim (Lithium battery isolator manager) in place of the old isolator system components.  Basically what it does is allow charging of house Lithiums, chassis lead acid batteries and then gives the alternator a rest (Cooling) these generally operate on a timing system rotating among all 3 stages while you drive. To be clear,  I removed 3 major original pieces, charging 3 wire brick (trickle charge chassis batt. maintainer). (Isolator delay relay delay Diesel) And battery isolator relay.  LiBim replaced battery isolator relay.  My point is: All of these orignal components work well for lead acid or agm batts. Also including shore power charging.  (All components are needed obviously). One more thing, I have found that many of the small black relays on the coach system are the same and available at places like Amazon.  You have to look for small print.  

Hope this helps

Which specific BIM are you using that allows for 3 stage charging?  I still don't like the Off-On timing, but if it indeed managed the charging like a 3-stage charger (even though there are only 2-stages in Lithium Charging), this would be an improvement.  I've talked with a couple of the major manufacturers about 6 months ago, and neither had any control over charging current (charge profile).

  -Rick N.

[Ivylog]

Rick, I’m sure we all thank you for taking the time for your good, long posts. I might have 24 hours/year of below freezing temps…not enough to spend any money on. I’ve been using a switch to disable by BigBoy (house battery charging) for years getting 10 years out of the AGMs in a previous DP. Current rig is still using some AGMs …I disconnect/isolate the Lithiums and store at 50% while snowbirding for 4 months in SE Fla.

Yes, the panels along the rail can be flat or tilted the opposite direction… picture below.