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Update on Lithium Battery questions & purchase


Al F

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This is an followup from questions I asked about Lithium Iron Phosphate (LFP or LiFePO4) batteries in Dec 2015 in topics about Balqon batteries and Starlight Solar.

 

In the above topics I asked about experiences with both companies and received lots of great replies. Thanks to all who responded earlier.

 

The short story is, I purchased the 400AH Lithium Battery kit from Starlight Solar in Yuma, AZ. I finished installing the batteries about a week ago and so far I have been very pleased with the whole package.

 

The ordering process was quick and easy, everything arrived in about a week. Shipping charges were not overly expensive, about $150.

 

The primary reasons for buying from Starlight Solar:

 

– Some comments from knowledgeable people on this forum that the installations done by Starlight Solar has been quality work.

– So I figured the components they provided would be of good quality. (what I received looks to be good quality)

– The lithium batteries and BMS system appear to be coming from an established quality manufacturer and if there is a failure of a component, replacement parts should be available.

– Phone and/or email support from Starlight Solar is readily available.

– I didn't have to source the individual components, batteries, BMS, relays, etc.

– The price of the kit is not greatly more than the price of sourcing buying the components myself and is competitive with other battery packages I have seen online.

 

If you decide to buy this battery package from Starlight, do be aware this is a kit. You will have to assemble all the pieces and build a number of cables to connect everything together. There are no detailed assembly instructions. A wiring diagram is provided and in the link I gave above, the photo of the assembled battery package is what I used as a guide as to where & how to place the components. Larry at Starlight Solar is available to answer questions and has been very responsive to my questions.

 

The battery package consists of four 100AH lithium batteries, a BMS (battery management system), contactors (big relays or solenoids), fuses & miscellaneous parts, and a 7” flat-screen monitor.

 

The batteries Starlight Solar provides are these from Elite Power Systems and the BMS is also from EPS. You can read more about the batteries and BMS in the above links.

 

I really like the BMS and the monitor which displays the status of all the individual cells (16 cells total for the 4 batteries). The BMS immediately shuts down the charging or discharging of the battery package if any cell is over voltage or under voltage. This protects your significant investment in the lithium batteries. Much more info and details about BMS systems and why you want one in the info links below.

 

The BMS system and monitor seems to provide most of the functions of a battery monitor such as Trimetric. However since I already had a Trimetric monitor installed I kept my monitor installed. The Trimetric uses the same shunt as the BMS so it just attaches along with the BMS.

 

Before starting a Lithium battery project here is some recommended reading:

 

http://www.pbase.com/mainecruising/lifepo4_on_boats While written for the boating community, this is a great review of the pros & cons of Lithium batteries and their operation.

 

The following links go to info found on BatteryUniversity.com. Lots of great info on this website. However the info is generally not always specifically about the LFP batteries we use in RV's or boats.

 

http://batteryuniversity.com/learn/article/types_of_lithium_ion

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries Note, the voltages referenced in this link are for Lithium Cobalt batteries not the LFP batteries. However I believe the principles are the same.

http://batteryuniversity.com/learn/article/lithium_based_batteries How do Lithium Ion batteries work.

http://batteryuniversity.com/learn/article/what_is_the_c_rate Many articles refer to charging “C” rate. Simply put, if a battery is 100AH and the charge rate is 100 amps the the charge rate is 1C.

 

Two articles from Technomadia, early implementers of LFP batteries. I have not read these articles, but others have referenced them.

Lithium Ion Batteries for RV Motorhome House System - LFP / LiFePO4 | Technomadia

lithium ion | Technomadia

 

 

A 322 page topic from a boating forum here. Lots of great discussion of the actual used of LFP batteries. Also in that topic are links to two more topics of interest about LFP batteries.

 

 

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In my original posting I mentioned the BMS flat screen monitor. Here are a pair of sample displays from my system showing the type of info displayed.

 

Monitory%201%20r_zpszdt2vvig.jpg

 

 

Monitor%202%20r_zpsrepso1eq.jpg

 

The above displays are from immediately after install, before the batteries have been fully charged.

 

 

 

 

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Additional components in my total solar/battery/charger install are a pair of 325 watt Kyocera solar panels, wired in parallel, a MorningStar Tristar 60 Solar Controller, a Magnum PSW 2000 watt inverter/charger and a Trimetric battery monitor.

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Thanks Al,

For sharing your experance. I see by your Stats that you like photography. Could you post some pictures of your work, Batteries, cableing, and BMS. I'm sure others would love to see what this kind of setup looks like.

Thanks Al

 

Kent

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Popped back into the coach to pick up a few items. 11:20AM Yuma time.

 

IN

46.5V

85-93W

.03A

 

BATT

13.5

5.9 - 6.7A (fluctuating constantly)

FLOAT

 

Really do need to pull up the MidNite manual again, as I use it so infrequently I forget how to stroll thru the settings for other readings:)!

 

Best,

Smitty

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How does the engine alternator feel about charging? Based on the link to the marine guy, these batteries can tax an alternator. Any comments, yet?

I don't have my lithium batteries charged by the alternator. Since the alternator will put out up to about 15V that is higher than what the lithium batteries can handle. While my BMS will cut out the plus side of the battery supply if anyone of my 16 cells go over voltage, I don't want to risk it.

 

I not as interested in trying to charge from the alternator as I would be if I had lead acid, because:

 

-- Since I have 650 watts of solar to charge 400AH of lithium battery, my solar should do a good job of keeping the batteries charged. Also since I have about 300AH of usable capacity from the 400AH of lithium, instead of 100-150AH of usable from lead acid at 400AH.

 

-- with lithium, when I charge from the inverter/charger by running the generator, I can put in more amps in an hour. With the lead acid the charge current would quickly taper off after about 30 minutes and after about an hour I was down to about 20-30 amps instead of 80-100amps. I have not verified this yet, but I will be in a couple of months when we get on the road.

 

-- Unlike lead acid batteries, the lithium doesn't need to be charged to 100% to get long life. In fact it is better for long life if you only charge the lithium to about 90-93%.

 

 

It seems the boating community, when charging from alternator, adds some controls to limit the voltage going to the battery.

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Hello,

 

I've been following attentively everything related to LiFePO4; the lighter weight, capacity to be drained of up to 80% of total charge, and ability to be charged to 100% really fast (ie, in just a single, fast "stage") are very tempting.

 

But I'm really unimpressed by the price: $3417 (plus freight, and what about tax?) for 400AH? An equivalent setup using 6 Lifeline deep-cycle AGMs[1] (for 3*220= 660AH, therefore even at 50% DOD offering more than the 320AH "drainable" capacity of the LiFePO4s at 80% DOD) would cost less than 6*310= $1860 (*including* freight and tax), ie, almost *half* the price of the above LiFePO4s... :-/ It would only make sense if the LiFePO4s would last at least twice as long. In theory they should, but in practice some folks are seeing very different results[2].

 

Happily we're still 12-18 months away from having to make that decision, let's hope the LiFePO4 price situation improves in the mean time.

 

[1] http://www.invertersrus.com/gpl-4c.html

[2] http://www.technomadia.com/2015/02/living-the-lithium-lifestyle-3-5-year-lithium-rv-battery-update/ (scroll down to the part that begins with "The Dark Cloud: Premature Battery Aging").

 

Cheers,

--

Vall.

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Hello,

 

I've been following attentively everything related to LiFePO4; the lighter weight, capacity to be drained of up to 80% of total charge, and ability to be charged to 100% really fast (ie, in just a single, fast "stage") are very tempting.

 

But I'm really unimpressed by the price: $3417 (plus freight, and what about tax?) for 400AH? An equivalent setup using 6 Lifeline deep-cycle AGMs[1] (for 3*220= 660AH, therefore even at 50% DOD offering more than the 320AH "drainable" capacity of the LiFePO4s at 80% DOD) would cost less than 6*310= $1860 (*including* freight and tax), ie, almost *half* the price of the above LiFePO4s... :-/ It would only make sense if the LiFePO4s would last at least twice as long. In theory they should, but in practice some folks are seeing very different results[2].

 

Happily we're still 12-18 months away from having to make that decision, let's hope the LiFePO4 price situation improves in the mean time.

 

[1] http://www.invertersrus.com/gpl-4c.html

[2] http://www.technomadia.com/2015/02/living-the-lithium-lifestyle-3-5-year-lithium-rv-battery-update/ (scroll down to the part that begins with "The Dark Cloud: Premature Battery Aging").

 

Cheers,

--

Vall.

Yep, they are expensive.

 

The things that pushed me to spend the extra $1700 (cost based on your cost of the 6 AGM's). BTW, no taxes since the batteries were shipped out of state. Shipping was only about $150, not cheap, but not excessive.

-- size & weight. 6 AGM's will weight what, about 260-300 pounds? and take up much more space. My 400ah package weighs 130 pounds and is ~11"x23"x9"

-- fast charge and discharge to 70-75% to be conservative. Even AGM for good battery life shouldn't be discharged beyond 25%. That's 220AH, not the 330AH stated.

-- Not needing to worry about charging to 100% on a regular basis.

-- Lastly....cause I think the technology is at the point I am willing to take the plunge. :)

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Thanks Al,

For sharing your experance. I see by your Stats that you like photography. Could you post some pictures of your work, Batteries, cableing, and BMS. I'm sure others would love to see what this kind of setup looks like.

Thanks Al

 

Kent

Here are a few pictures. Not much to see.

 

Storage compartment with solar controller, sub panel, inverter/charger & battery assembly:

Storage%20Compartment_zpstf7ecj0t.jpg

 

A closer look at the battery assembly:

Battery--BMS_zpseb6iw0rh.jpg

 

A close up of the Battery monitor computer:

BMS%20Computer_zps2rehoik0.jpg

 

One of the four batteries with the BMS boards on each battery cell.

Single%20Battery%20amp%20BMS_zpsrk34jb11

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I suggest you do a bit of reading on the subject, the batteries being discussed here are not a fire risk. It's an interesting area of technology that is moving to the mainstream quickly.

 

The batteries causing fires are not the same chemical formulation as the ones being discussed here. Those batteries were commonly known as LIB batteries (LiCoO2) and do have a fairly high fire risk. I would not consider them for an RV application.

 

The batteries being used in RV applications are either LFP (LiFePO4) or LFMP (as used by Starlight in this application). These DO NOT have this fire risk and have huge advantages in weight, charging profile and life span. While pricey upfront, in the long run their longer life makes them a cost effective option.

 

There is extensive information out there on this subject both as cited by Al and in many other areas by googling Lithium Ion, Dreamliner, LFP and so on.

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Not to be sour grapes on lithium batteries, however after viewing the many news media reports on lithium batteries causing fires, don't think I would want them in our coach.

 

Best regards & safe travels to all....... :)

I decided on the Lithium after doing a fair amount of research, some of which I included in the links I provided at the beginning of this topic. As stated by NJTroy above the lithium batteries we used in our RV's and by even more people in boats seem to be very safe.

 

Lithium batteries which are used in high discharge rates are more susceptible to overheating and starting a fire. By a high discharge rate, I mean taking a 200 amp hour (AH) battery (this is the AH capacity of typical golf cart or AGM battery used in an RV) and discharging it at 400 amps or even as high as 600amps. If you read some articles and informative websites where you see references of charging or discharging a battery at "0.5C", "1C", or "2C" this means discharging a 200AH battery at 100amps (0.5C), 200 amps (1C), 400 amps (2C), or 600 amps (3C).

 

My 400AH capacity lithium battery pack will have a discharge rate of about 100amps when running my microwave or coffee pot. Also with a 2000 watt inverter I should never see a discharge rate above about 160 amps.

 

Additionally the battery pack I installed has a Battery Management System (BMS) which monitors the voltage and temperature of every cell in the battery pack. If any single cell goes over or undervoltage or over temperature the BMS disconnects the battery pack from the discharging or charging source.

 

There is lots of good info in the links I provided at the beginning of this topic.

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The fire safety topic has been beat to death as a foru search would show.

 

Two things get me about these comments (1) the presumption that someone spent hundreds of hours researching and implementing cutting edge technology without ever considering fire hazard and (2) an apparent unawareness of lead acid battery hazards.

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Vall, with regard to price, you can do things cheaper, it just comes down to how much you feel comfprtable doing yourself. You could get the battery cells for 2,000.00, probably less, http://store.evtv.me/proddetail.php?prod=ca100fi. You then need to add 100 to 240 for shipping. Also you need to figure in the cost of connectors and, if you want, a bms. So lets say 2600 for the whole works. Also the BMS, (I am figuring in the cost of one not as nice as the one depicted), is a fixed cost as is much of the wiring set up. So if you want to move up to an 800 Ah system the price point is soewhat lower. Dave

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I have been communicating with someone at the company that was providing Balqon with Housepower BMS circuit boards and cell monitors. He told me he had heard Balqon was out of business. I made numerous attempt to contact Balqon to get them to honor warranty without any response before giving up and buying replacement parts directly from supplier of Housepower BMS. (name slips my mind at the moment but I posted links I n another thread). I would not buy anything from Balqon again.

 

Jim

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Dave and Lana,

 

I first e-mailed and left messages at Balqon a couple months ago, including CEO? Samra's e-mail and phone number that he gave me when I bought our battery pack. It was about two weeks ago that Dimitri at Clean Power told me Balqon had been using their BMS hardware and he "had heard they had gone out of business". It was just one more of many anecdotal indications they were out of business.

 

The silver lining for me is that when I dissected my BMS enclosure, I indeed found Clean Power's Housepower BMS board. Balqon had potted it as well as the cell monitors, but after sending photos to Clean Power, they confirmed them to be their products. They did not understand why Balqon would cover the diagnostic LED's on both products. I am guessing Balqon didn't want them to be easily identifiable so as to make it less likely folks would not just buy components and build their own battery packs.

 

If I could do it over, I would try to follow what David Dixon is working on with a 48V used Volt battery. My second choice, would be to build my own 12V battery pack with four cells like what I have now.

 

Jim

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Thanks for those that have shared the problems they have had with certain 'rebranding' suppliers. It is the nature of the beast on while not 'new tech', but for sure 'new markets' for emerging technologies - that the combination of all our crooks, and those that while well intended, but not well experienced in business - can cause start up problems for new consumers...

 

This does not make the 'newly marketed technology' unsound, or bad, but it does cause problems with warranty and tech support. Early adopters have risked this path, and both been rewarded, and at the same hurt.

 

Best to all that are going down this trial ahead of what may become the masses... And for sure, hope solid businesses do well ahead too:)!

Smitty

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