Seen a Deal on OfferUp.. Not sure if I did good.. if not I will sell them on ebay or something
They say 50Ah each one at 3.2v
there are 16ea in each box and I have 4 boxes and a contraption I think for the charging that I might not need.. They sit at 35v as wired right now..
How many AH can I get out of this? any ideas?
PAckage deal for $440.00.. did I do ok? or No?
So if my math is correct.. 3200ah for $400? ^.^d
50x16=800 per box x 4 boxes.
Are they fully charged? Man that's a lot of wiring... you can run your ac if it all works.
How's the footprint? Looks like cell-tower backup batteries
I can reconfigure if needed.. Not sure how the math works on these to get total AH. I was thinking 800ah at the end of the day but guessing..
14x14 square , maybe 16x16 but I can make new boxes.. think I need to get new bms and wire them all to 12.8v .. something to do
Sorry, I didn't see 3.2v each.
That's 4 for a 12v system, so 3200÷4=800ah still GREAT DEAL AND NOT LIKE normal systems at 50% capacity, true 800ah.
That was what I was thinking.. Maybe Tim can help me with what BMS boards to order .. want to get them connected and charged up
Looks like a good deal to me. Will depend on how many cycles they have been through. If used as a battery backup probably very few cycles. From the packaging they look like high quality cells. Should be fun to play with.
If wired for 12v you should be able to charge with your existing charger in coach. Do some research to find out what voltage you need to charge for a 12.8v lithium system. I would think in the high 14v range.
Please keep us up to date as you progress.
see ya
ken
I would configure them for 16 volts and charge to 14.8 volts. That way you will not over charge them and they will last longer.
This is how I configured my Chevy volt batteries. At 14.8v you can use the coaches charging systems, you can also add solar for more flexibility. Most all 12 volt devices will run at 14.8 volts. That's what most alternators charge at. I would not worry to much about a BMS, do your research. I don't run one, but I do keep and eye on the balance of the cells. I use a 20 amp hobby charger to balance when there's a need.
I think you did good in your buy. Have fun I do.
Did you bottom balance? (read a little on it last night). If 16v will worrk with everything in the coach I might do that and simplify. Would I lose AH from being done that way?
Also can you share your setting for charge, float and bulk.. and anything else you think?
640ah That's still more amper hours than 90% of everyone that's out there...
Had some work done by the electric bike dealer in solana beach, ca.
He makes up the BMS for the San Diego area rickshaws that use li-ion
SDEB (http://sdebike.com/)
Being as these are loose you might check with him. At least to verify condition?
My worthless two cents.
I watched as his BMS was turning off a strip of leds which indicated those cells were balanced.
Three cells per circuit? I think Tesla uses that same grouping?
This is new territory for me. You're saying lithium batteries can be charged with a voltage less than they put out???
see ya
ken
I think how it works, if you wire at the 12.8v max there is a max charge of 14.4-14.8 area.
Wire them to be 16v you will still max out on the charge side at the 14.8v as that is what the natural charging is on the coach but because you added the extra cell at 3.2v you could actually charge higher according to the max charge per cell (not sure what that is b) but the 14.8 is under that for sure so the batterys is being charged less that 100% per charge thus extending the battery life.
Just guessing from what I have read
Yes charge less does not cause a problem over charge will kill them. So if you setup for 12.8 you house system will kill them. I use a section of the Chevy Volt battery and reconfigure them from 48 volts to 16.8 volts. These 48 volt section are 2 kw amp hours. Check out Chevy Volt batteries or any of the other car manufacturers on uTube. Lots of stuff there.
David, your post inspired me to do some searching for more information. Found this http://batteryuniversity.com/
Are these new batteries or used? I'm guessing used since they appear to have wiring for a BMS and series connections at the terminals. What are your plans for them?
The one thing I found in the above article is that once they are fully charged, charging should be stopped. No float voltage etc.
Li-ion batteries prefer the same temperature as we do, not hot or cold. Maybe leave some space between the cells for cooling. Still a lot to learn about LI-ion.
I am going to take them all apart this weekend, see what is good or not. Connect 5 together and charge or look into bottom charging.. Use in the motorhome.. looking easier than I was thinking originally
They are definitely not charged as you probably know. 16 connected in series at 3.2v should be 51.2v. If the voltage is 35 that is 2.18v per cell. Battery U states the operating range of the Li-iron-phosphate is 2.5 - 3.65v. If you can get them charged then you can run a discharge test to see if they produce 50 Ahr, which they may not as capacity decreases with age and use. Still you may have a good buy. Charging Lithium-Ion Batteries – Battery University (http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries) This article is mostly about Li-cobalt rather than iron- phosphate. Let us know what you find out. I like the idea of connecting 5 in series for safety and long life, but you will get less than 50 Ahr doing that. Overcharging and a venting with flame incident might ruin your day.
My 69 mo old Chevy Volt with 35K mi can still go almost 40 miles on a charge (42 when new), but EV's are built for long life. Not sure what the chemistry is in that Li-ion battery.
Cold or hot can kill them dead. Would not mount them outside the main body shell. No desert hot use?
Is there a specific piece of the battery bank on the volt that can or can not be converted to 12v(or 16v) to make them usable?
Been wanting to get one and convert but was nervous about getting the wrong one
5 cells are bad out of the bunch.. ended up with 59 cells ^.^d
Very happy with that except I am 1 short of making a complete battery using 5 cells each... Maybe I can find one online for cheap.. so far no :'(
Some of the cells sit at 3.20, 3.19 respectively.. So do I need to bottom balance if they are matched up in voltage if I am able to?
If the charging system doesnt go over the 14.8 then in theory I should be ok I would think.. then I can take the oddballs and charge or discharge to get them to match. In Theory?
Assuming I am grouping in 5 cell pair
My solana guy and Tesla do three cell groups as far as their BMS. Probably better cell balancing?
Large discussions online.. better reasoning for the bottom up balancing ... it will never get to high with my application but it can get to low if 1 cell is goes out of balance
I had a few cells that were bad.. 5 overall..
Took one apart to see what and how they were made. Not the cylinder type its sort of a pad.. pics included. Any ideas on MAx Amps I can charge at..
Anyone with Lithium want to share charging perimeters for the inverter and if you have solar the charge controllers?
Plan was
Charge limit 12.8
Not sure on the rest though
David I don't remember who you bought your Multipass from but AM will send you a script to set your charge parameters. Allan probably has the same thing. Also in the Multipass manual they have the settings. The solar charger simply is changed at the bottom left with a dial. It's manual also has the setting. I don't want to steer you wrong but you can also email the tech guys at victron and they are very good about a quick answer. You need to have a PC and NOT anything else.
I talked to Bay Marine tues and received my dongle today.. good people.. Maybe I will call him and ask about the programing.. thanks for the heads up. ^.^d ^.^d
Installing the batteries this weekend ..
Allan @ Bay Marine has been a great help. This is an early pic of my solar on other days
Here are your LIFEPO4 cell recommendations:
Discharge to no less than 2.5V
Charge to no more than 3.6V
Bottom balance to 2.5V. Get all the cells to hold at 2.5V, then charge normally.
Don't bother top balancing or balancing at anything less than 3V.
Store at 3.3V, or about 50% SOC (State of Charge).
To maximize battery life: 1. Operate battery between 80% and 20% SOC (State of Charge) 2. Charge and discharge between 40F and 90F degrees.
Strap them together so they don't bulge.
I use the Orion Jr. BMS. They are on sale for about $183 on eBay. Good insurance policy, but it takes a lot of research to engineer the connections properly. PM me for the connectors and crimp pins to use. The Orion Jr. BMS connects to a Windows Laptop via an inexpensive RS232 cable so your battery pack becomes "sentient" in that you read every cell voltage, pack current and pack SOC. It can also set alarms, relays, etc...
For my 12V pack (Four 400AH batteries) I charge with an iCharger 4010DUO intelligent RC charger. It can charge, discharge, balance and send a storage charge to the batteries.
What is the best way to keep the alternator from overcharging? Where does the charge wire tie into the batteries?
Was going to run the batteries in pairs of 5 but now I am second guessing.. maybe just run in 4s and adjust the alternator? I have the dongle for the solar and the directions for the inverter, going to set them up but the alternator is my real question?
or disconnect it from the house for now
David,
This might answer some of your questions.
DIY Lithium Batteries: How to Build Your Own Battery Packs: Micah Toll:... (http://www.amazon.com/gp/product/0989906701/ref=ox_sc_sfl_title_34)
It's been well recommended on some of the lithium battery sites.
If you do get it please give us a review. :)
see ya
ken
I will give that book a try.. going to go with the 4s setup and i can always change it later.. going to disconnect the alternator to the house as I have solar so that shouldnt be an issue and adjust the charge perimeters .. Alternator is my only questionable charger.
Not sure what I need to make that end work.. Also does the house battery only charge from the inverter when plugged in or is there another charge box I need to work around? Kinda remember someone talking about a hum and maybe 2 boxes?
Two things:
(Definitions: House battery = Coach battery. Engine battery = Starting battery)
ALTERNATOR
I plan on disconnecting the alternator from LIFEPO4 Engine battery. I may use a 4LB lead acid VRLA battery for the alternator to charge, just for a third backup battery.
ENGINE BATTERY
For starting and running engine systems a 400AH LIFEPO4 battery will be used. It will be charged with the iCharger 4010Duo Smart charger, which will be powered by 115VAC through an IOTA 12V (DLS-12-30) power supply.
This battery is suitable as a deep-cycle House battery backup, since it is lithium.
BOOST CIRCUIT
Eliminated.
BACKUP POWER
The concept of the traditional diode-based circuit will be installed using two silicon (.6V drop) and one schottky (.3V drop) diodes. See schematic diagram below. Features:
1. 12Volt House power maintained in the event of house battery failure.
2. Independent smart charging of House and Engine lithium batteries. Includes SOC management and bottom balancing).
3. Solar, shore or generator power used for charging House and Engine batteries.
I have isolated my house and engine battery banks with a manual switch. In the almost two years now, I have never needed house to alt charging. Really don't like two battery types in circuit. Not smart enough to do all of work you described.
Still use alt with engine of course as well as solar panel.
Boost circuit removed from driver side. Larger capacity circuit can be used in either direction or combined from house battery compartment. Ran 2/0 to selector from engine bank.
Allan is a great source.
Sounds great. Here are photos of the engine battery system I will install next month.
The analog meter is the State of Charge indicator from the Orion Jr. BMS, with full scale equal 100%.
how many amps can I safely run through them? everything is connected and adjusted except the alternator.. 105 degrees out and hot..
when I run the microwave is it ok for them to drop below the 12v range? Or at anytime as long as it is a draw and not the actual sitting volts of the battery?
Something else I thought about.. How does the current flow from the generator? Through the inverter? Or is there a separate charger?
My 400AH lithiums can produce 3000Amps.
I recommend not charging Lithium with an alternator. Do it through a smart charger SPECIFICALLY designed for LIFEPO4, including individual cell monitoring. Don't buy into false claims that chargers can be set up to manage lithiums.
It's not about total pack voltage. A voltage down to 2.5 Volts per cell is acceptable, but each cell must be monitored and a low-voltage alarm or relay must disconnect the battery below this voltage.
I have designed my system to charge with 125VAC, so the inverter, genny, shore or solar can be used. I may design an emergency backup charging system through the alternator, which will limit charge current to about 20 amps, just to take it easy on the alternator.
Is a 50amp or larger charge ok? I set the PV for 20amps just dont know if its to little
David one last comment from me on this one. I agree on the alternator as mentioned before but some of your tech issues can be answered on Victron tech blog for your specific equipment. If you want to use your alternator take a look at the Cyrix for example. Those systems were designed to be used for lithium charging. Now that may very well be because their battery's onboard systems interface by proprietary design but I haven't seen anything to support that thought.
You may want to examine AMS new control card. I spoke with Allan late last year and he may be reselling I am not sure. I attached a couple of schematics. One stand alone and one integrated.
Muttering from the wilderness as you guys are way above my weight class. Good luck!
Two comments:
1. Charge Rate
a. My 48V 180AH solar lithium charged at:
Shore or genny power: 15 Amps, or about 750 watts
Solar power: 30 Amps, or about 1500 watts
b. My 12V 400AH lithium will be charged at anywhere between 1 and 30 amps, depending on the plentifullness of the power source: E.g. Solar vs shore power.
2. Victron and AM solar
These are great companies. If you have big bucks, I highly recommend their products. They sell quality products that will increase the value of your rig. I am a "value" investor, and chose not to pay 3x for products that I could procure, engineer and maintain myself. As the old bromide says "You get what you pay for".
If you are managing charge of BYOB (Bring Your Own (Lithium) Battery) cells, I do not believe Victron or AM Solar can help you. Cell-based monitoring mandatory a must to prevent cell damage and start possibly a fire.
Our coach has a 600 AH LiFePo4 bank from AM solar with all Victron components. The BMS is Victron. The parameters are for Victron batteries only. You must find out what your specific battery needs are to safely charge and maintain them. BMS is essential for lithium.
Last week we ran down our batteries by accident when we though we were on shore power but forgot to sent the transfer switch to shore ( we have a manual transfer switch for safety) The BMS shut down the system. With no BMS, permanent damage would have happened. Good luck with your setup.
How did that happen with Solar?
Bob, sounds like we have a similar system. My earlier reference was to the settings for the Multipass and the solar controller. These have settings for non Victron lithium as well.
Solar can't keep up with the a/c. We had tied into our home shore power that I had installed, and the 2 a/cs were pulling more than the 30 amp one I plugged into. Had to switch it to the 50 amp. With Victron you can limit the amount of amps pulled and I could have set it for 25, but it was at 30, wife didn't know that so it tripped the breaker. But the BMS saved the day.