Lifepo4, need list of components!

[timoat]

Hey everyone, decided to go for lifepo4, but im unsure of exactly what I need to get a system up and running. BMS, can I use a regular tracer 20 A Mppt Charge controller, what about battery isolator, do I need a special one, fuses etc. Links would be great!

Im thinking of a 300w mono panel, and a 90-150Ah bank.

And what physical dangers are there?

 

[VanKitten]

Ok... this is what you need

Batteries...of course.....
Then,

Battery balancer. Battery Management system. Mppt charge controller that can deliver 2-4 stage charging.

Everything else is no different that you would have for any battery system.

The only issues with lithium is that it does not perform well if you charge them when they are too warm or too cold.
Recommend you get the cells encased in aluminum as it will allow heat transfer quicker than the typical plastic. Also.install fans and ventilation. And a low power heating pad.

Also..lithium does not like to be kept at full charge. If you will not be using power for a few days..set your mppt to cut off before full charge.

But these are more of an effect on longevity.

The ones that explode or catch fire are the cobalt lithium.

I recommend you have a talk with the guys at
http://www.electriccarpartscompany.com/

I can post diagrams if you need them....

 

[Scott7022]

Good Source and one I had never seen before. I like the sprinter van set up but wonder at the high jump to charge off alternator option Looking back and forth between the two; alternator and sprinter I don't get the price jump. A simple DC to DC controller would do the trick. Like the Sterling or Blue Sea DC to DC, The Blue Sea even has a lithium unit for DC starting to DC house.

Still a great resource. Loads of options and hmmmm points. I got kind lost in the 12 Compressor area for AC...Loads of HMMMMM

I went with Battle Born because of the service and hell yeah it will do it attitude. But I wish I knew about this place earlier!!

 

[jonyjoe303]

If you buy an off the shelf 12.8 volt lifepo4, thats a drop in replacement for lead acid. Those already have a BMS, the bms is like a relay if the voltage gets too low or too high it shuts off the battery. You can use any solar charge controller mppt or pwm. They recommend you disable the float voltage but with off the shelf lifepo4 probably not needed. The BMS will also keep the battery balance automatically. The 12 volt ones they sell are usually in the 100ah range. 

If you decide to build your own, you do need a BMS, but they are inexpensive, I use a 30 amp 6 dollar one, but if you want car cranking BMS that will be in 40 dollar range. Also I use an overvoltage relay (7 dollars), that will shut off power no matter what if the battery reaches 14.4 volts, it acts as a deadman switch. On these cheaper BMS, they mostly monitor the balancing, if the battery goes out of balance they shut off the battery before they get damage.  

These are the voltages the lifepo4 operates at, fully charge voltage is 14.6 volts and fully discharge voltage 11.2 volts. Well within the range of lead acid.

I been using my 110ah lifepo4 I built for the past month and it's been connected to my 20 amp ecoworthy mppt, its been performing excellent. I have to crank up the absorb voltage to 14.8 volts to try and fast charge it, at the normal 14.4 volts it charges slowly at about 4 amps. Even at 14.8 volt it charges at 10 amps or less, even though the controller is capable of 15 amps. The controller see's a fully charge battery and keeps the amps down. The battery has so far stayed in balance, but I do have a 14 amp isdt q6 balance charger just in case. To fully charge the battery I do need to use the balance charger and hit it with 10 amps for several hours, the mppt controller so far has never been able to get the battery up to 14.2 volts, its never tripped the overvoltage regulator. Unlike lead acid, lifepo4 doesnt need to be fully charge, it won't get damage from undercharging. 

The off the shelf lifepo4 are design with many built-in safety features, they are as safe as they can be. If you build one, you have to use fuses everywhere, monitor the balancing at all times, make sure you have a good bms, and for me an overvoltage relay is essential to shutoff charging when the voltage gets close to the maximum in case the bms fails. I been using lithium for almost 2 years and never had any problems, I started off using the laptop cells which are more dangerous and built a 94ah pack, lifepo4 is many times safer and at 14.4 volts I find it hard to overcharge. The most dangerous lithiums are the rectangular soft packs used in the RC world, those are very sensitive to catch on fire when overcharged.

picture of my 110ah lifepo4, it shows overvoltage regulator led on the left and the balance voltage led on right. And there are 2 xt60 connectors in the rear where I plug into it. In the month I have been using it, the lowest voltage I seen is 12.9 volts and that's using it all night as I would my lead acid. It holds voltage well. In the morning it mostly sits at 13.1 volts. 

 

[frater secessus]

I attempted to distill the LFP info from the giant sailing thread into a couple of pages of reading.

The most interesting tidbit from a vandweller point of view is that "Fractional C" use may not require BMS.*  There are folks on the forum running that way right now with good results.  I plan to run mine "barefoot" after my golf cart bank shuffles off this mortal coil.  


* and that BMS failure under normal conditions may be a leading cause of LFP cell death.

 

[CampingOdyssey]

I'm also considering going with a lithium battery to save on weight and size.

I came across a LifePo4 12V 50Ah on amazon, made by a company called Waterblade, for around $400 that looked to be a pretty good deal. Not sure it is ideal for using in the back of a campervan though. I read in the link provided by frater secessus (thanks for creating that) about the different ways batteries are charged/discharged. Says a battery in a electric vehicle is charged/discharged at a rate that is higher than its amperage capacity. Whereas a rv battery is charged/discharged at a lower amperage than its capacity (fractional c). I read in the stats for the LifePo4 by Waterblade that it has a max charge/discharge of 70a which is higher than it's capacity... so, does that suggest it is not best suited for the needs of a running an electrical system in the back of a campervan?

I also found another lithium battery (not sure if it is lifePo4 or not) by smartbattery, for around $700. That battery seems to be geared towards solar/rv crowd and says deep cell on the front. I also read in the specs that the max charge/discharge is 50a which is the same as its capacity. Would this battery be better suited for running an electrical system in the back of a campervan?

As far as charging it, eventually I want to go solar, but to start off I was considering setting up an isolator on my van (honda odyssey). However, all the isolators seem to have a amperage that is too high (120amp - 200+) for a lithium battery. I had the idea to use a 300w inverter (found it on amazon: BESTEK 300W Power Inverter DC 12V to 110V 4.2A) in my vans 12v cigarette lighter, and then plug a battery charger into the inverter. For the battery charger I found the genius brand G15000 which can charge a battery at 15a. I checked in the specs and it says it only uses 255watts of electricity so it seems that it would work in the inverter plugged in the the 12v cigarette lighter, but not sure on that. Any idea if that would work? If so, what battery would be best to do it with the LifePo4 by Waterblade or the one by smartbattery? Thanks.

 

[Scott7022]

CampingOdyssey. Quick answer to the last sentence. I had never heard of Waterblade so I had to go look. If you read the directions at the bottom the lack of English grammar and Syntax is obvious. I am not being racist against non English, please don't read into that. But as a company if you are going to market and sell a product to English speaking consumers and you can't afford to have instructions translated correctly what else couldn't you afford to do correctly. As for Smartbattery, they had a pretty lousy customer service rating three years ago when I started looking into my project. I just checked again and not a great deal as changed. The Florida BBB doesn't rate them and they have active complaints as of 2017. https://www.bbb.org/west-florida/bu...ttery-in-tampa-fl-90118446/alerts-and-actions

Lithium is not cheap. Doing lithium cheaply is going to end up costing more for less. If cost is a factor, then go with Firefly Carbon foam Marine batteries. You will get the best bang for your buck and almost lithium performance from a system that is relatively simple. IF weight is the factor and you HAVE to shed the pounds, like I did, then it is not going to be inexpensive.

You really need to sit, have a beer and think about it.

Inexpensive, Easy Button Solution. Firefly. 1 or 2, they are group 31 size and a little lighter. No charge concerns for alternator charging, simple isolater from the starting battery and correct cable, fuses, to the battery.

Expensive, but Easy Button Solution. Goal Zero Lithium unit. Pick the one you need based on usage requirments. I am not a big fan or anything but they are getting great reviews and they have done the Lithium system correclty. ArcPak is an Ausie company doing something similar but you have to add the battery and it is kind of we help you do it yourself fix and reviews on doing Lithium are all over the place.

I WANT LITHIUM cause without it I can't legally drive the vehcile or take my dog. Battle Born lithum batteries from Nevada. Great reviews, American company focsed on Customer Serivce. I bought 6.

Your vehicle engine is not a great power generator. It is designed to recharge the brief dip starting and keep up with energy uses as you drive. So converting 13.7 up to 110 and then pluging in another device, even it can handle it, to down covert it from 110 to 14.1 to charge a lithium battery is a very long walk. Lithium batteries need a specific charge profile and I don't know if the Genius brand can do this. But it is a moot point as unless you are driving like 5 hours a day, this is not going to work well enough to keep you from killing your expensvie battery earlier than it's lifecycle.

Lithium battery is must and I refuse to give Goal Zero money for something i can do. Second thing to think about is Charging. Solar, Vehicle, Generator, or combination. Ideally the BEST is all three. The BEST in life is expensive. I would not suggest doing a DIY all three system. But buying a little red Honda and two suitcase style solar panels would be a good option. The solar keeps you topped up and if you really have bad days of high usage and low sun then the little Honda is leaps and bounds cheaper charging source than the van. Quiet, efficent, and will run for 8 hours on 3 bucks in fuel.

I hope you and others will find this helpful. The pages from the Sailing World that Frater compiled is a must reading just to know what people are talking about when they are attempting to sell you something.

If you have the bandwidth click this link and watch the video on alternators and how charge controllers can affect them. It is at the bottom of the page, past the charge controller I use. Answers the Why does it take so long to charge my battery from my 300 amp alternator?
https://baymarinesupply.com/charger...ng-alternator-to-battery-charger-400-amp.html

 

[VanKitten]

If the goal is to do this in the least expensive way, then you need to buy the individual cells and assemble it yourself.

The trade off is always going to be your money or your time.

I think most people end up going plug-n-play ... the expensive routine .... (or not doing lithium at all) is because the learning curve is steep and it takes some determination to go down that road and persever.

Do it your self will end up costing about $200 for 12v 50ah. If you want plug and play it could cost you twice, three times that (or more) and you will be disappointed because the battery will not preform to your expectations. Plugging a lithium into a charge controller that is designed to delivery what lead acid need is one way to shorten the life of lithium. Failing to have battery balancer and BMS is a bad idea. Over sharing a lithium battery it dangerous. Keeping lithium at full charge is not good for them.

So, I suggest you either bite the bullet and dig into learning how to do this yourself...or buy the best full system you can. Anything else is not only expensive...but the shorter lifespan of those batteries will make it even more expensive because you need to replace them too soon.

 

[frater secessus]

If you read the directions at the bottom the lack of English grammar and Syntax is obvious. ...  But as a company if you are going to market and sell a product to English speaking consumers and you can't afford to have instructions translated correctly what else couldn't you afford to do correctly.

Wading through Chinglish is part of the price of buying inexpensive stuff from China. 

If I wanted to scare folks off Battle Born / Dragonfly (which I don't) I'd say something like:  "Their website says the batteries are made in the USA.  But the cells made in China by Dynavolt.  If they lie about that what else would they lie about?"

But I don't because that would be fearmongering.

 

[frater secessus]

Plugging a lithium into a charge controller that is designed to delivery what lead acid need is one way to shorten the life of lithium. 

If the controller has adjustable setpoints it will almost certainly be fine for Li.  And if it doesn't have adjustable setpoints it's already shortening the life of the lead acid battery.

 

[Scott7022]

Wading through Chinglish is part of the price of buying inexpensive stuff from China. 

If I wanted to scare folks off Battle Born / Dragonfly (which I don't) I'd say something like:  "Their website says the batteries are made in the USA.  But the cells made in China by Dynavolt.  If they lie about that what else would they lie about?"

But I don't because that would be fearmongering.

Yes, the cells are made in China. Lithium isn't mined in the USA or Canada. The difference is they are assembled, tested, certified, and most importantly carry a warranty from a US based company that has to follow laws and practices. Dragonfly switched production just recently. Will they go the way of the famous Redtop batteries who knows. 

I guess it comes down to what your piece of mind is worth. I didn't receive  a discount buying my six. I don't do paid endorsements and have received nothing from either company. In fact, I bought five at a price higher than the deal they have now. I have been following Lithium since TechnoNomad built their rig, six or more years ago. I can do it, I understand it. But for me, this was the way to go.

I wasn't trying to fear monger.  I just pointed out my observations. Here in Russia you can buy, iPhones that say assembled in Cuppertino America and iPhones that don't. The stores tell you it is all the same. No warranty difference here. But USA, assembled are 20% more. They sell twice as many US iPhones as they do Chinese. Why do poor Russians buy the more expensive phone? Both have the same warranty. Piece of mind

 

[CampingOdyssey]

For the past few months I've been researching solar and was planning on putting together a set up using AGM batteries. Planed on using a 100watt flexible solar panel with a cheap amazon PWV charge controller to charge 2, 100ah AGM batteries. Figured on 10 awg wire with 20amp inline fuse for charge controller to battery bank and the same 10awg wire with a on/off switch from charge controller to fuse block. To connect the two batteries I was going to use 2 awg wire. By my estimate the whole system looked to be around $700. I saw the $400 Lifepo4 lithium battery from Waveblade and it seemed to be priced just a bit more than the 2, 100ah AGM batteries ($360 for the two) I was going to purchase. Figured lithium would be the better option because I could save some weight and get about the same power out of a 12v 50ah lithium compared to 2, 100ah AGM batteries. I read somewhere that with a bit of tweaking with the charge controller, I could just interchange the LifePo4 lithium battery into the same system I had planned to use for the AGM batteries. But, if I risk destroying the battery I may just stick with the AGM batteries.

I remember seeing the Yeti goal zero a few months back when I began searching and wrote it off because of lack of power (think I was looking at the Yeti 400). After looking at them again today, I see the Yeti 1000 Lithium. That looks to be enough to power for my needs (plan on having the smallest 12v Dometic fridge, a maxxfan, a couple lights and fans as well as charging my laptop). It looks like a total plug and play system with the Yeti 1000 and a 100watt solar panel would be about $1600. But with the 100ah Lithium in the Yeti 1000 that should be twice the power as the 2 100ah batteries or 1 50ah LifePo4 battery. So, considering that, an extra $1000 for double the power and a plug and play system doesn't seem that bad (by my rough estimate it seems an equivalent 4 battery AGM set up would be about $500 less). Considering the weight reduction, portability and ease of use with the Yeti 1000, I'm almost leaning towards the Yeti now. Does anyone know if I could wire a fuse bock to it (was going to use the blue sea system 12 circuit blade fuse box) that way I could hardwire multiple 12v appliances (namely the fridge and maxxfan)? Do you think the Yeti at that price is worth it? Going a total DIY with lithium seems to be a bit much to undertake at the moment but will check out a few sites to see if its something I may be interested in trying.

 

[jonyjoe303]

the goal zero lithium 1000 is 10.8 volts 97 ah battery pack, it uses the li-ion cells (laptop batteries) , the goal zero lithium 1400 is 10.8 volts 132 ah it also uses li-ion batteries.
Any battery pack that uses lifepo4 will be 12.8 volts.
The lower voltage won't be any problem for most items, I used my 11.1 volt 33 ah li-ion battery pack for a month as a house battery and not once did my inverter quit working from low voltage. It ran everything that I would run with my lead acid.
A 50 ah lithium will be comparable to a 100 ah lead acid. The lithium you can take it all the way down to when the bms cuts off power, the lead acid will only go down to 50 percent.

Unless you will be using all the power a lithium can put out everyday, the cost (1600 dollars) is too much. At the end of the day it is just a battery. I went 4 years with just a 102 ah agm. The 400 dollar waveblade lithium if its 12.8 volt lifepo4 seems to be a better deal. You might realize you only need 50 ah. 12.8 volts is very close to lead acid voltage.

In 2 months of using the 12.8 volt 110ah lifepo4 battery I built, I realize its more battery than I require, its never gone below 12.9 volts. But  I'm already building my second 110 ah lifepo4 batterypack, and debating about getting a 3rd one. But I already bought the tab welder and might as well use it. The cost is less than 200 dollars per battery pack, that is comparable to a high end agm. And weight of the battery is about 30 pounds. 

As far as charging a lifepo4 with a solar charge controller, the bms will cutoff power when its full. You can also lower the bulk absorb down to 14 volts and it will never get full, it will just charge very slowly. My solar charge controller see's my 12.8 volt lifepo4 as a fully charge battery, and charges it very slowly.

 

[Scott7022]

Depending on the Yeti model one has a little 8mm and the other has more, plug in the front of the unit. You come off that 8mm plug and into a fuse block distribution. It is internally short protected so easy to connect. It puts out 12 volts at 10 amps or 120 watts max. Then you have the car plug style for computer or dual USB out to tablets and cells. The AC side is pure sine wave 1500 watts continious and 3000 surge. I couldn't find in the literature how long that surge is five seconds 30 seconds but it isn't going to run a big microwave but it will blend a smoothy! Don't buy their solor panels you can get adaptor plugs for folding suitcase styles at much cheaper on Amazon. They will tell you via customer service how many watts they can use depending on the model. Anderson style power port will take 14-22 volts up to 20amps. Charge off the car cigarette plug while driving, no issue for the car and will take forever to charge, but Lithium likes being off fully charged so no issue. Small enough to tuck into a small bag and plug your laptop and goal zero to a powerstrip in the bag and one cord into the library outlet.