Lithium Battery Insights from New Install

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Lithium Battery Insights from New Install

March 10, 2021, 02:52:44 pm

We recently posted interior and energy system updates to our 2000 34' U270 here.

This post will provide our insights to how the system, including 1200w of solar and 600 Ah of Battleborn lithium batteries are performing. The Cerbo GX module gathers and reports a dizzying amount of data. We brought the coach home on Sunday, February 27. Batteries were @ 100% and we parked the coach at our house but disconnected from shore power. The first picture, below shows the historical data from the date. The pink color is energy usage, the orange is solar energy produced and the blue shows the range of battery state of charge (SOC). During this time the coach was basically turned "OFF" so we could turn "ON" various systems and monitor power demand.

Running AC on Battery

When we got home late in the afternoon on 2/28 we turned on one of the new Domestic 15k AC's we had installed (with soft start). Power demand to run one AC is about 1600 watts. We ran the AC for about 3-4 hours while showing neighbors the interior updates. Battery SOC dropped to about 70% that evening and the system was back at 100% SOC by 2pm the next afternoon with only baseline DC and AC demand as discussed next. We also tried running the AC for about 3 hours on 3/2 during the peak solar production hours of 10 am to 1 pm. Battery SOC dropped from 90% to 60% but between 1 pm and the end of the day battery SOC was back over 70% and by 2pm the next day the system was back at 100% again with only base loads as described below. We DO NOT plan to run the system for air conditioning on a regular basis as we try and camp in areas where AC is not needed, but its nice to know its available to cool the coach down if needed. I'm guessing it would take twice the battery and solar capacity to do much more with the AC....and at 34' we simply don't have the real estate to do more. The second picture below shows just some of the data available to document usage between 2/28 and 3/3 as just discussed.

Baseline (Minimum) DC and AC Draws

Since we brought the coach home we've been experimenting to see what energy is used when operating various systems on the coach. To begin we evaluated how much power was used with everything OFF. The first question was what "OFF" means. We turned off the inverters so there would be no AC power consumed and no DC consumed by the inverters in standby mode. We found that DC power with everything turned OFF was about 70-80 watts. We turned off the leveling system and usage dropped to about 20 watts. This is presumably the lowest consumption without disconnecting all batteries...just things like the smoke/CO2 and other DC systems which are active even when the coach is "OFF". It should be noted here that if the coach were parked in a garage without shore power and without solar input, even this small draw would eventually draw down the house batteries. The Battleborn battery management would eventually disconnect the house batteries when they reach something like 10 volts. We installed a Victron Battery Protect module which is set to disconnect 11.25v as a more conservative protection value.

Baseline draw from our Victron Multiplus 3000 is about 8-9 watts simply by being turned ON but with no AC loads being used. We do have a smaller Victron Phoenix 800 inverter that provides AC power to our "front overhead" electronics including TV, DVD player, and chargers for iPhones, iPads and laptops. This would allow the big inverter to be turned "off" overnight when boondocking but still providing for these overhead electronics. We haven't reinstalled the TV and related overhead electronics yet so I'll update this post when we see what the draw is from using that small inverter by itself.

Testing Coach Systems on Battery - Refrigerator on Electric

We replaced our original Dometic refrigerator/freezer with the same model shortly after buying our coach. It runs on propane or AC. On 3/7 we turned on the fridge using DC power and ran it until 6 pm on 3/8. From the 3rd picture below you'll see that the fridge consumes about 330 watts of electric. SOC running only the refrigerator dropped from 100% at 9am to 55% by 8 pm. By noon on 3/9 SOC was back to 100%. CONCLUSION: By itself the fridge consumes a lot of battery power. Ideally only use electric when attached to shore power or in an emergency if propane has run out and electric is the only way to keep food cold.

Testing Coach Systems on Battery - Ice Maker on Electric

We use our Uline ice maker continuously when traveling. After turning the refrigerator off and allow the batteries to return to 100% I turned on the icemaker and water pump switch on at 9 am on 3/9. You can see the AC consumption rise to 187-225 watts as the ice maker cooled and you can see the "blips" as the water pump turned on to refill as ice was made. By about 1am on 3/10 the ice maker was full and you can see the AC consumption fall off except for brief periods when the compressor turns on to keep the ice maker temp below freezing. Battery state of charge during the full run cycle only got down to about 70% overnight and by 1 pm the SOC was back to 100%. CONCLUSION: We can easily run the ice maker continuously while dry camping since once ice bin is full the pump will only cycle as needed to maintain full capacity and the compressor will only need to run periodically to keep the compartment cold.

Testing Coach Systems on Battery - Water Heater on Electric

Water heater will need to run on propane when dry camping. Power consumption at startup was 1300 watts, nearly as high as the air conditioner. I only ran it for a brief time but I assume that after water reached high temp cutoff the power demand would be substantially less. Regardless, propane will be the best route for hot water.

Testing Coach Systems on Battery - Furnace on Electric

Our propane furnace uses DC so the inverter does not need to be on to provide furnace heat. The furnace fan consumes about 125 watts so it is clearly the source of heat when boondocking.

Testing Coach Systems on Battery - Other Systems on Electric

Our ceramic heater draws 1650 watts when running. A hair dryer draws similar wattage when used. Our microwave can also draw in excess of 1100 watts.

After we get the overhead electronics re-installed and operating off the small inverter I'll provide similar information.

Preliminary Conclusions

Since 2/28 our solar arrays has produced 29 kWh of power or about 2.8kWh per day. I'm writing this at 2:30 pm on 3/10 and so far we've brought in 30 kWh of solar. Eventually we'll be watching what our needs are on a 24/7 basis while actually on the road camping. We'll be out 6 months this year with at least several weeks of dry camping. We'll also test how much shore power we need even when using full hookups without the electric turned on. Equally important will be the effect of rainy/cloudy days on solar production as well as the demand for things like the water pump for daily use of drinking/cooking and showers.

Testing Coach Systems on Battery - Generator Backup

Regardless of solar system performance the coach can automatically start the generator if house voltage drops lower than 11 volts. Generator use hours can also be programmed to observe quiet hours in campgrounds. The generator can also be programmed to automatically start when AC demand rise above a certain threshold, say 1600 watts, so we can program the Dometic AC to turn on a particular time of day, say 2 hours before we return from hiking, and once started the generator will start to preserve battery power. Then when the Dometic reaches shutoff and power demand drops, the generator will stop.

Manual generator start and stop is also possible using the Color GX pad or remotely from a phone/pad/computer as long as the coach has internet access.

Can I Enjoy my Foretravel Without All this Stuff

The answer is YES. The coach as delivered had the ability to provide several days of camping before running into energy distress. Generators would start when batteries reached critical levels. The challenge we found was that several days of use without daily generator supplementation, would draw the batteries to a point where it might take most of the day to bring lead-acid chemistry batteries (including AGM and Gel) back to 100%. Although short use of the microwave and hair dryer was possible when off shore power, battery capacity would be more rapidly reduced. We found ourselves having to think about battery use on a daily basis if we weren't hooked up to shore power.

This system basically means we no longer have to think much about energy use. With more solar capacity and lithium batteries we can live almost as "normally" off shore power as we did hooked up. And even "emergency" AC use is a possibility if we accidentally find ourselves in hotter temps than we normally try to camp in. Yes, there's a "geek" factor to all this but I was pleasantly surprised to see just how easy the system is to setup and how little "minding" is required once its set to your satifaction.

Stay tuned for updates. Also happy to answer questions.

Randy and Karen

Re: Lithium Battery Insights from New Install

Reply #1 – March 10, 2021, 04:05:14 pm

Two thumbs up for your post. Good input on rear world conditions. Good snapshot of how solar, lithium batteries and propane work together to make outstanding dry camping possible without any disadvantages.

Pierce

Re: Lithium Battery Insights from New Install

Reply #2 – March 10, 2021, 04:44:38 pm

You guys SLAY me!!!! Makes want to be a better explainer.. I am a 5 words or less kinda guy

I can not do that but again I bow to you for this write up..

Re: Lithium Battery Insights from New Install

Reply #3 – March 10, 2021, 05:07:27 pm

Thanks for the info Randy. Your Dometic use looks like peak AC demand is about 330 watts but it is not on ll the time, on/off/on sort of thing. And there appears to be some low level minimum use. If you have a Kikk-a- watt meter you can plug it in between the outlet where the Dometic AC plugs in and the Dometic itself and it will add up the actual watts used over time. If your base line is 20 watts and the peaks are 330 maybe your average is maybe 150 watts. In 24 hrs that is 3600 watts.

You went from 100% SOC to 55% SOC in 11 hrs. That is 45% of your 7200 watt hr total rated capacity or 3240 watts hrs. In 11 hrs that is 294 watts per hour. That indeed is a huge amount. By contrast our Samsung residential refrigerator uses about 1720 watts per day measured over a month or an average of about 72 watts per hour.

When we are dry camping, not using the AC, we use about 3000 - 3200 watts per day total even when using heat at night, going from 100% SOC to about 55%, mid morning to 8AM. So those numbers align well. Get a Kill-a-watt meter and test. It will not include power on demand for the inverter or inverter efficiency losses. To measure that you have to load sensor to measure amps and watts going into the inverter and compare that to watts used coming out of the inverter.

I have a Color Control GX, the predecessor to the Cerbo GX and on it you can see DC loads in real time. If you turn a light on you can see how many watts it is drawing from the battery instantly.

All of this detail is interesting, fascinating as Mr Spock would say. Tools to improve the way you use your coach with knowledge. And you have added the means to enhance performance for many years.

We have been on the road since late November and have not used 120 v sources for battery charging at all. All solar for all 12v use and we have been at 100% by 10 AM or earlier on almost every day even with significant clouds. The main thing 120v is used for is the AH on electric.

Good job, Randy. We need to keep comparing notes.

Re: Lithium Battery Insights from New Install

Reply #4 – March 10, 2021, 08:25:30 pm

Floridarandy,
I envy your setup, but would really like to know, 1) did you install all the electrical upgrades yourself, and 2), if you don't mind telling, how much does this type of upgrade cost.?

Re: Lithium Battery Insights from New Install

Reply #5 – March 11, 2021, 07:28:49 am

All work on our coach, after purchase in 2017 in NAC, has been done by Paul Yasbeck in Leesburg, FL...done right the first time...a real pride in his workmanship. And, at rates lower than NAC.

Re: Lithium Battery Insights from New Install

Reply #6 – March 11, 2021, 09:29:37 am

Quote from: floridarandy – March 11, 2021, 07:28:49 am

All work on our coach, after purchase in 2017 in NAC, has been done by Paul Yasbeck in Leesburg, FL...done right the first time...a real pride in his workmanship. And, at rates lower than NAC.

My folks live in the Leesburg area and I was referred to Paul by a fellow Foretraveler we met at a local park back in 2018. I needed a transfer switch replaced and he also installed 2 Lifeline AGM 8D's for us. Very professional and insisted on removing his shoes before entering our coach. Top notch. "Done right the first time" is key here as it is so hard to to find places to do quality work today.

On your project, I am getting ready to do more with my current setup as well. This information is just what the doctor ordered! Keep it coming! Impressive. Enjoy your coach.

Re: Lithium Battery Insights from New Install

Reply #7 – March 11, 2021, 12:23:48 pm

Dave. "Doing more" has to be lithium batteries cause you already have the magnum and the solar happening.
So, go for it, bite the bullet , write the check. I see that there are new upgrades for lithium batts but I doubt that going stop any time soon. Whatever lithium you do will be obsolete to some small degree as soon as it's done.

Like Bill would tell you " TOO MUCH IS JUST RIGHT " 👍

Re: Lithium Battery Insights from New Install

Reply #8 – March 11, 2021, 05:02:35 pm

Bob,

You are correct. I'm currently looking at the Battle Born's. I see they now have a 270ah 8D drop in replacement (not sure I want to keep that footprint). Like a kid in an ice cream shop! Who knows. I'm not sure what flavor(s) and how many scoops, but I'm not going to skimp on anything. I just don't want to have to worry at all about what I'm running when boondocking.

Re: Lithium Battery Insights from New Install

Reply #9 – March 11, 2021, 07:22:19 pm

At this point it's important to distinguish the benefits between parts of this install. If we had installed the Battleborn batteries alone, without solar and the other monitoring modules, we'd have the bulk of the benefits from this install. That is, longer times between recharge and much faster and easier recharge from engine or generator. So if your simply want to increase how long you can go without worrying about batteries buy the Battleborns. Less than $6k Getz the batteries alone assuming you have an adequate inverter. Maybe the last coach batteries you'll ever need.

Travel from campground to campground and don't ever overnight without hookups? Don't fool with any of this!

Re: Lithium Battery Insights from New Install

Reply #10 – March 13, 2021, 10:07:33 am

The coach has now been at the house for nearly two weeks unplugged from shore power. We've been in and out and run the "attic fan" (Kool O Matic) for several hours a day, and as discussed above, a lot of switching different loads on and off. Coach has stayed at 100% so at least for longer term "parking" we're good "off the hook".

Re: Lithium Battery Insights from New Install

Reply #11 – March 13, 2021, 10:51:49 am

On the other hand, quite a few owners won't have the $6K for the Battleborns. They are one of the best ways to go if in your budget and Randy has done a superb job of documenting his experience. I have to say that I wish we had a compartment full of them.

For those with a Tesla appetite but a Ford Falcon budget, we poured over Craigslist back in 2008 until we found these Genesis XE70-0771-6001 12 Volt 68 Amp Hour Battery new $435 AGMs for $35/ea no tax. The deals are there if you keep searching. The six are still working well today fully charged mid-morning and working as well as when we installed them.

I keep waiting for our ship to come in to the dock but learned to take a panga with the old Evinrude out to where it's anchored and hope the cargo does not sink the boat.

Pierce

Re: Lithium Battery Insights from New Install

Reply #12 – March 13, 2021, 11:15:30 am

I had never check on the price of ion batteries when I bought the silicone batteries but I see that they are half the price. They don't
need anything special to charge them and they can be charge in one hour.

Re: Lithium Battery Insights from New Install

Reply #13 – March 13, 2021, 03:03:18 pm

The purpose of this thread was to document our "energy" experience with our solar/battery install... not to justify our investment or suggest everyone should do what we have done. Everyone must do what they think is best for their particular camping style and budget.

We actually think our solution, for us, will turn out to be less expensive over the years we plan to use our coach, make it easier to camp where we want without having to monitor electric, minimize generator run time and provide a meaningful resale value when we do hang up the keys.

Re: Lithium Battery Insights from New Install

Reply #14 – March 14, 2021, 11:06:28 pm

Randy,

Your original posting and reply # 3 are about the best I have read on this forum.

But then, I am an engineering nerd.

Regards

Klaus

Re: Lithium Battery Insights from New Install

Reply #15 – March 16, 2021, 04:28:40 pm

Hey Randy,
Did you ever find that missing part for the cerbo?
John

Re: Lithium Battery Insights from New Install

Reply #16 – May 08, 2021, 12:36:53 am

We're about a month into our 6 month trip with the new energy management/battery system. So far preliminary observations:

1. 1260w Solar and 30 amp Victron Orion battery to battery charger has kept 600ah Battleborn house batteries at 100% while traveling without generator and running Uline ice maker 24x7, propane fridge on electric and overnight with no hookups with "usual" TV and device charging and a little early morning propane furnace blower.

2. Run one AC on battery for 4-6 hours boondocking without solar. More testing to see how much longer we can run AC during the day with solar offset and how long it takes to return to 100% with solar alone after using AC cool down before a night without hookups.

3. On 30 amp hookups we can run everything mentioned above as well as the 2nd AC using the Multiplus "assist". Looks like overnight on battery with both AC's is possible. More testing to see if solar can recover 100% the next day. NOTE that both our new Dometic 15kw have soft start.

Attached below is the house battery state of charge since we left April 19.

MUCH more to learn and our system reports all metrics so ask if you are curious.

Re: Lithium Battery Insights from New Install

Reply #17 – May 08, 2021, 01:14:03 am

Randy,

Post like yours are on top of the list why I am addicted to the Forum.

I just came back from my shake down test run to Texas, and learned a lot about battery performance, which I knew very little about. ( My power generation background is with equipment in the upper MW range)

Roger, Pierce and now You are my heroes.

Regards

Klaus

Re: Lithium Battery Insights from New Install

Reply #18 – May 08, 2021, 01:56:14 am

An excellent thread, Randy, with great documentation. Thanks!

For those of us that have LiPoFe batteries and are not full timing, there's an easy way to reduce the aging of the batteries. Since LiPo ages slower when stored at 40-50% SOC, I reduce the charger bulk to 13.0V, and float voltage to 12.7V to keep the batteries in that range when the coach is in storage. Ours is stored indoors, so the PV charge controllers settings don't have to be changed. On those rare occasions when we're at an RV park, and plugged in for more than a few days, I reduce the charger and PV controllers to the lower settings. I put them back to the normal settings the day before we leave so we're on the road with a full charge.

Greg

Re: Lithium Battery Insights from New Install

Reply #19 – May 08, 2021, 10:31:33 am

I leave a couple lights on when I store mine to try and keep it cycling and not sitting. Read it helps but time will tell. Love the lithium's.

Re: Lithium Battery Insights from New Install

Reply #20 – May 08, 2021, 11:02:54 am

Quote from: kepeters – May 08, 2021, 01:14:03 am

Randy,

Post like yours are on top of the list why I am addicted to the Forum.

I just came back from my shake down test run to Texas, and learned a lot about battery performance, which I knew very little about. ( My power generation background is with equipment in the upper MW range)

Roger, Pierce and now You are my heroes.

Regards

Klaus

Klaus, thank you for the kind words but Roger and Pierce are who I learn from. And, they can actually "do" the design and installs of these systems. I enjoy learning how things work in practice, but I have no technical theory background and choose to use my time putting these systems to use while traveling. I'm fortunate to have a gifted Foretravel expert in Florida, Paul Yasbeck, who put the ideas I learned here into place. Yes, more expensive to do it this way but for me it's the right, and probably safer, way to go.

Re: Lithium Battery Insights from New Install

Reply #21 – May 08, 2021, 12:04:59 pm

Quote from: MisterEd – May 08, 2021, 01:56:14 am

Since LiPo ages slower when stored at 40-50% SOC...

Since this is not what Battle Born recommends for their LiFePO4 batteries (at least I don't see it anywhere) where is this coming from?

Battle Born suggests storing their batteries fully charged whether for a few months or over the winter. In cold weather of for longer times they suggesting diconnecting both positive and negative cables. This is a good reason to put in disconnect switches on both sides before fuses or shunts. You can store them at less than full charge but losses over time maybe more.

Part of the reason for this and why they suggest returning to 100% SOC when you can is that the BMS will balance cell voltages when you reach this state. Cell balancing only happens when you get to 100% SOC.

Battle Born also recommends charge rates at or below 20% of maximum capacity to maximize cycle counts. (At least 5000 with 75-80% original capacity remaining. This is the only reference I have seen that talks about maximizing battery life.

I use a Sterling ProCharge Ultra 40 amp smart charger when I need to charge the batteries (House or Start) in addition to solar. The charger in my Multiplus is almost never on. The Sterling monitors the battery state and will quit charging and go into an ultra low power standby mode when the batteries don't need charging. It checks on the batteries periodically and will start up again as needed. Most of the time in the barn this is in standby mode.
Sterling ProCharge Ultra 40 Amp Boat Battery Charger

Lithium chemistries used in phones, laptops and other devices benefit from lower than 100% SOC charging and storage.

Re: Lithium Battery Insights from New Install

Reply #22 – May 09, 2021, 09:23:39 pm

Quote from: Roger & Susan in Home2 – May 08, 2021, 12:04:59 pm

Since this is not what Battle Born recommends for their LiFePO4 batteries (at least I don't see it anywhere) where is this coming from?

I bought three 200ah, 12V lifepo4 batteries two years ago. From the manufacturer, they all came charged to 40%, and that is where I've maintained them.

I believe if I charged them to 100% or 40% they would still outlast how long I have my FT with my light use. I've seen this 40% number for storage from several sources. For me, long term storage will most often be at 40-50%. That being said, most all my storage will be at 100%. For me it is a combination of what is best, and what is convenient.

"2. Keep the lithium battery at a 40%-50% charge level during storage time:"

"In view of the self-discharge of lithium-ion battery, keeping the battery at 40%-50% discharge before a long period storage is necessary because over discharging will lead to irreversible capacity loss of battery and the battery may not be activated again. As you can see from the below table, a moderate temperature and 40% battery charge loses less amount of power. Furthermore, batteries are not items you can put away for the winter and forget about. They have to be checked and maintained throughout the entire time they are in storage."

How To Store Your Lithium-ion Battery In Winter? | Lithium Ion Storage | UFO...

How to Store Lithium Batteries | Lithium Battery Storage Buildings

Re: Lithium Battery Insights from New Install

Reply #23 – May 09, 2021, 09:55:36 pm

Jack, the chemistry of Lithium-Ion batteries in these references is not specified and there are several different types.

This particular manufacturer may recommend a procedure that is good for their batteries. It is different from Battle Born's recommended procedure. This may be because of different chemistries and differences in the behaviors of the BMS controllers that each manufacturer uses.

These batteries are expensive, do what you want to do, I am going to do what the manufacturer of my batteries recommends.

Re: Lithium Battery Insights from New Install

Reply #24 – May 09, 2021, 10:25:06 pm

Quote from: Jack Lewis – May 09, 2021, 09:23:39 pm

I bought three 200ah, 12V lifepo4 batteries two years ago. From the manufacturer, they all came charged to 40%, and that is where I've maintained them.

I believe if I charged them to 100% or 40% they would still outlast how long I have my FT with my light use. I've seen this 40% number for storage from several sources. For me, long term storage will most often be at 40-50%. That being said, most all my storage will be at 100%. For me it is a combination of what is best, and what is convenient.

"2. Keep the lithium battery at a 40%-50% charge level during storage time:"

"In view of the self-discharge of lithium-ion battery, keeping the battery at 40%-50% discharge before a long period storage is necessary because over discharging will lead to irreversible capacity loss of battery and the battery may not be activated again. As you can see from the below table, a moderate temperature and 40% battery charge loses less amount of power. Furthermore, batteries are not items you can put away for the winter and forget about. They have to be checked and maintained throughout the entire time they are in storage."

How To Store Your Lithium-ion Battery In Winter? | Lithium Ion Storage | UFO...

How to Store Lithium Batteries | Lithium Battery Storage Buildings

Jack,
I've Read the same thing about lifepo4 batteries from numerous sources and when I bought cells from the long boat from China they came in at 50%SOC on all 8 cells. My trouble is I haven't been able to get a definition of how long is considered "Storage" ?? 1 week, 1 month, or several months. I, like you, usually turn off my disconnects on both sets of my batteries when I leave my coach in covered storage for any longer than a few weeks.

But as Roger says DWMYH

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