Lithium Batteries, who has them?

[Peter]

Terry, You have a great idea to inform us slowly about these new batteries your information will be gratefully received. Many thanks for sharing your knowledge . In 4-5 years I wonder how many of us will have converted to lithium batteries.

[T1 Terry]

Terry, it reads to me that lithium batteries are not always the answer. You have said they are expensive and difficult to fit, so what are the benefits of this risky modification then? Would they cost me as much as my Jayco is worth?

I have no idea what you consider your Jayco is worth and that may turn into a mud slinging match if that question was put to owners of other makes Comparing usable Ah between battery chemistry type using a cut of voltage of 12v under a 20% load as the bench mark for the end of the usable capacity, lithium batteries are roughly the same price as medium quality AGM and flooded cell, cheaper than gel cell and heaps cheaper than quality flooded cell and AGM batteries.
As far as the protection system, you can run with no protection system with any battery, it won't last the normal cycle life but lithium batteries will live through abuse that would kill any lead acid battery.
I really don't understand why anyone would spend that much money buying any type of battery and intentionally not install some form of battery protection so I'm opening the door to understanding what forms of protection are needed and what is a waste of money, and believe me, there is a lot of waste of money stuff out there.
As to whether converting to lithium is right for you, I'll reprint here the post I put up on the Caravanner forum on a similar topic http://www.caravanersforum.com/viewtopi ... =2&t=52229

Hopefully this is the sort of information you are after, so here is a basic comparison for you.
What you want to do while caravanning is the question you need to ask yourself, that answer will decide if a lithium battery is for you or a waste of money and just stick with lead acid.

Stick with lead acid if:
You caravan park hop and not free camp at all
Use your van for 1 day only free camps and only want to power the lights and a tv for a few hrs
and
You are set up to plug the van in as soon as you get home to keep the batteries full and float charging

Upgrade to lithium if you:
Prefer to free camp and intend to stay in that location for more than over night
You want to use a coffee machine, bread maker, hair dryer (insert household item here) from an inverter rather than a generator
Fast recharging would be an advantage to you
Weight reduction would be an advantage to you
Extended battery life would be an advantage
You would like more usable capacity without increasing the weight
You would like to remain independently powered without the need for a generator
You have a compressor fridge and you want to free camp
You don't want the hassle of having to fully recharge the battery every time you use it and would prefer not to plug in to power just for the sake of the batteries

Price is not really a consideration these days, comparing usable Ah while staying above 12v lithium and lead acid are close enough to the same price. You can fit a completely basic system if you want to, but just like lead acid batteries, you will get a longer life with a battery monitor. You do not need to buy all new equipment to recharge or use lithium batteries, the stuff you already have can be adapted to suit.

T1 Terry

[slowhand]

Feel a bit better now after reading the link and posts from Terry, thought it may just be me who suffered the pathetic abuse and denial when discussing lifepo4.

Before this forum, my first and only forum was the Aussie MotorHomers, (CMCA drivel), where I got into a discussion about lifepo4 and was not only abused, but had my posts refused. They threatened me, sent a warning because I disagreed with one of their ancient pasts their use by date drop kicks there. Who makes out he knows everything about everything and especially lifepo4, problems is, he knows nothing and posts very misleading and wrong information. The link from Terry, shows me this a common thing and it seems the same type of dills are on that forum as well. Bet they wouldn't have the guts to say what they do if they met you on the road and saw your lifepo4 system in action, typical of cowards.

It was the same when mentioning linux and open source, denial, abuse, lies and pure unadulterated fear of change and new things. Can't understand why people fear change and difference, especially when you can see the difference between lifepo4, lipo, gel, LA, even with small cell voltages.

I've got some AA lifepo4 batteries in my cameras, both still and video (take a lot of photo's and vid's) and the difference in usage time before recharge, is quite dramatic. Normally I change the batteries over nearly every day when I'm taking photo's, but the lifepo4 last 3-4 full days of shooting.

Personally, sticking with LA or gel, is like living in the 19th century, prefer the 21st so am almost fully lifepo4 and fully linux. Just started learning to build my own linux system from scratch and the software for it, then will build me a BMS program for the house and bus. Hope to write and install the program for a house monitoring system in the next few weeks. Have a very old laptop running puppy linux, so will put the program into that and see how it works. The laptop cost me $10 as no windows would run on it any more. Been able to get many different linux running on it, but puppy is so cool, small and efficient it fully runs in ram, which leaves the entire 10gig HD free for use and every thing's stored in a usb drive.

My daughter suggested using a raspberry Pi for my house and bus systems, which would include the BMS and just about every form of adjustment and sensing. Checked out raspberry Pi and think I'll stick with old laptops until I understand it all better. My current BMS balances cells constantly and provides current inputs, outputs, charge status and remote displays, all programmable.

[Busman]

So what brand of BMS is this ?
Busman

[Mrcoolabah1au]

Make your own raspberry pi

[BobnBev]

Hi Terry and others, Yep they are the goods, its coming up to 3 years now in the van with a 200 amph LiFePo4 set up..
Its that good that we have started to put the flat on Lithium as well @ 24 volts, going to have a switch that will switch the 240 mains off and just run from the inverter, ( Peter its ok my grand son is a sparky ) so all above board...
A big thank you to T1 as it was his help that got me running as it is...I was changing the 18650 cells in the power pack on my Minelab detector but couldn,t under stand why the didnt go, ( didnt balance them before fitting) Thats when I went to Lithium in the van..best thing that happened..CF and T1 fighting the ......... mob.. Thats when the other forum started, I jumped in feet first... Wont comment on the CF , Only that some there missed out on a lot of fun.....
Thanks again Terry...
Bob n Bev...

[nut17]

Have had a 200 A/H LiFePo4Y system since April 2012. In the process of ordering a new van and the LiFePo4Y will be transferred to the new van and joined by an identical unit giving me 400Amp /Hrs. We will also be installing 980w solar and a Flexmax Outback 80 Amp MPPT controller to take care of the main charging duties and to power the 215lt Waeco 12v compressor fridge. Really looking forward to setting up the new van due for delivery in early January 2015. We really enjoy the freedom that the LiFePo4's provide us, particularly when comparing to the 200 Amp/Hr AGM systems we ran previously.

Cheers Chris From across the ditch in Hastings NZ

[slowhand]

So what brand of BMS is this ?
Busman

It was built for an EV and has been reprogrammed for off grid/Rv/marine. Will give you the name in a week or so. Have a few friends who are thinking of changing to off grid lifepo4 after seeing mine, so would like to make it as easy as possible for them, with long term security for their system. If they don't have to touch them, they are real happy.

The programming of it is still being developed and fine tuned, plus a couple of modifications on the horizon. Currently I'm pretty happy with it, but now there is a new program so that will have to be updated. Currently you have to install your own relay switches and there is yet a facility for switching on charge and usage, after they have been disconnected at voltage parameters, other than by hand.

You don't need to go to the sophistication that I'm using, there are many other simple but workable solutions. The aim of this BMS is to give people a system which they won't have to look at and it will run itself constantly, but you will have all the information you need and want right in front of you. It operates separately from the inputs and outputs, just balances the system, monitors it, tells you whats going on and switches the relays at your required voltages. The 12v BMS runs of the pack, the remotes run of the cells and the 5v current sensor runs of the main unit. The remotes do all the cell charging and discharging, as soon as you connect them they start working and indicate with LEDs whether they are balanced, charging or discharging. It will handle 64 cells and 600amps, so is pretty versatile.

There's an 8 cell BVM which is adjustable on the market with a monitor, they are less than $20 from china. They just give an alarm/switch at the voltage parameters you set. I use one to switch the relays the other way. Add a current/voltage display after your solar charger and you see the real inputs and not the panels, then one on the battery load wiring and you get outputs. All up it would be less than $50.

I've got them all and was amazed at the difference in input currents when using LA, then lifepo4. If interested will let you know as soon as the BMS is ready and that should be in a week or so I believe.

[Mrcoolabah1au]

Ok will keep my eye on the raspberry mite need to upgrade my bms

[T1 Terry]

Ok, part 1 of many
Putting some of the nonsense to bed:
There is no such thing as a drop in lithium battery.
It's a bit like an instant University degree, looks pretty but won't actually get you very far.

There is no such thing as a lithium battery charger or battery charger with a lithium safe setting.
This is because battery chargers only measure the terminal voltage, with a 12v Li battery that consists of 4 cells, these batteries are damaged at cell level so it's cell voltage that needs to be monitored, not battery terminal voltage.
I'll try to explain what this means and why it's important. The battery terminal voltage is the total of the 4 cells voltage added together, for example 3.45v + 3.45v + 3.45v + 3.45v = 4 cells totalling 13.8v and every thing is fine with the world. But 4.5v + 3.3v + 3.0v + 3.0 = 4 cells totalling 13.8v and one completely stuffed cell. This is only using 13.8v as a max charging voltage, if you look at some of the supposed lithium battery chargers they have charging voltages of 14.4v or even 14.8v as their end of boost setting. Add anther 1v on to any one of the 3 remaining undamaged cells in the last example and you would now have 2 wrecked cells, that's half the battery. No, that cell at 4.5v won't go any higher till all the electrolyte is boiled out of that cell so it will be one of the other cells that gets overcharged and damaged/killed.
Hopefully from this example you can see why cell voltage monitoring is the key and therefore any system that only looks at battery terminal voltage is likely to destroy your rather expensive battery.

More Tomorrow and I'm afraid it might not be pleasant news for some.

T1 Terry