LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[deckofficer]

T1 Terry,

I have contacted Winston, as it was their news release announcing Balqon as their retailer. Balqon's biggest fish is the Port of Los Angeles, and as no surprise there is a lot of CMA alumni in high positions at the port. I've emailed all my fellow alumni and mentioned that they should exercise caution with their dealings with Balqon. Not long after, Elaine at Balqon emailed me, and she just happens to be a 2008 grad of CMA. She informed me the cells will ship ASAP. I'll believe it when I see it.

[T1 Terry]

Originally Posted by neelie

Terry - Thanks for the reply. Now get back to your book!! I'll be the first one to buy it.

"It really is simple and straight forward once you know how.." .. but then, so is neurosurgery.

Therein lies the rub, Terry, to an expert like you its a no brainer. To a newbie, it can be overwhelming mainly because the dollar cost of failure is large. Hence I think I'll start with a single small battery and experiment. I have read through most of the posts on this thread, but get lost in the minutiae when two experts collide on a differing point of view.

Thanks for the hint of only needing a 5A charger. I see your point.

Goboatingnow.. Of course, you're 100% correct.
But we all need to start somewhere, we're all newbies in some some field or other. The reason why I'd like to "roll my own", is so that I can understand and maintain it. If I buy a turnkey system, I become prisoner to their proprietary technology and to their support and spare parts department. In the end, I may be forced into going down this route, at which point, high quality AGM's will begin to look a more attractive proposition.

If I can't go with generic off the shelf components, I'll give the whole idea a miss. ... but I'm not bloody giving up yet!

If you are in HongKong you will have no problem getting your hands on either Winston Battery Company cells or Sinopoly cells, both top of the line stuff, get 4 x 100Ah cells and links and have a play, PM me if you want any guidance and take your time to discover what this technology is all about and where it's limitations are. Everything has limitation but these cells are so far outside the limitation boundries of lead acid in every direction there is no sense in sticking with last centuries technology just because this technology is new.
I'm not an electrical engineer so my mind isn't limited by what was drummed into me at school, I challenge theories to see if the prove correct but use the basic understanding as a guide, jumping off a step on to the ground proves the law of gravity to me, I don't need to jump out of a plane. I am an Automotive Mechanical Engineer but that's only a fancy title for a mechanic :lol:

T1 Terry

[ColdEH]

Hi every one , I have been reading this thread for awhile now, these batteries look great !!!

So I thought I would just ask . This is my alternator,

http://www.ecoair.com/Portals/22/fil...4V-9-25-12.pdf

It has a fixed regulator that I can't adjust. The nature of the design I guess. Kicks out serious amps at 1800 rpm (260) and if you look at my other threads you can see how I have got it hooked up .

Now the question is will these batteries work for me ?

If so what kind of setup would be best ? 700 amp hrs would be what I would be looking for .

You guys seem to know your stuff with this technology what do you think ??


Regards

[T1 Terry]

Originally Posted by typhoon

Hi every one , I have been reading this thread for awhile now, these batteries look great !!!

So I thought I would just ask . This is my alternator,

http://www.ecoair.com/Portals/22/fil...4V-9-25-12.pdf

It has a fixed regulator that I can't adjust. The nature of the design I guess. Kicks out serious amps at 1800 rpm (260) and if you look at my other threads you can see how I have got it hooked up .

Now the question is will these batteries work for me ?

If so what kind of setup would be best ? 700 amp hrs would be what I would be looking for .

You guys seem to know your stuff with this technology what do you think ??

Regards

Do you need 700Ah useable or are you using the lead acid 700Ah capabilty as your bench mark?
I'll have a read through the alternator specs but heat will be the biggest issue, lithium batteries accept the max capable output from the alternator virtually all the way to 100% charged, most alternators are not designed to operate at 100% capacity for long periods, they simply overheat, 70% of their max potential output seems to be about the limit for continuous output, 50% for automotive grade units.

T1 Terry

[ColdEH]

Hi Terry , thanks for the info.

Take a look at this video

Eco-Tech Alternators - YouTube

,

this alternator should be able to control it's heat quit well.

Also , looking for 250 to 350 amp hours usable . So I figure to get 700 just for a buffer and extend the cycle life of the batteries ..

Regards

[ebaugh]

Originally Posted by typhoon

Hi every one , I have been reading this thread for awhile now, these batteries look great !!!

So I thought I would just ask . This is my alternator,

http://www.ecoair.com/Portals/22/fil...4V-9-25-12.pdf

It has a fixed regulator that I can't adjust. The nature of the design I guess. Kicks out serious amps at 1800 rpm (260) and if you look at my other threads you can see how I have got it hooked up .

Now the question is will these batteries work for me ?

If so what kind of setup would be best ? 700 amp hrs would be what I would be looking for .

You guys seem to know your stuff with this technology what do you think ??

Regards

If you cruise with that alternator on a propulsion engine, you will need to have a smart regulator OR reduce the maximum output voltage to around 13.6V. 14.4V, the default output I saw, is too high for continuous charging.

[yamez4u]

I had the opposite experience with Balqon as you, My order was shipped very quickly and they called me three or four times to confirm detail. They did not except credit cards when I ordered. And normally places that do don't charge the card till the order ships. They might want to start following that practice. I notice on there site they clearly show the lead time on orders. Some as high as 3 weeks, what item did you buy? What is the lead time on there site for that item? I guess I got mine so fast because I ordered raw cells, they did not have to install a case or BMS.

[deckofficer]

Same here, just the cells but I asked for banding. (8) 100 a-hr cells and when I ordered plenty were in stock, but quoted 3 weeks. Now it has been over 3 months since they charged my VISA card. I'm glad you had good service from them and that is why the forum here is so useful. If nothing but positive about a company, then a good endorsement of that company, while a negative or two about a company will keep you cautious.

[T1 Terry]

Originally Posted by typhoon

......
this alternator should be able to control it's heat quit well.

Also , looking for 250 to 350 amp hours usable . So I figure to get 700 just for a buffer and extend the cycle life of the batteries ..

Regards

I had a look on the link you posted, 3 internal fans sounds like the goods. They mention the output voltage can be adjusted at the factory and there is seperate terminal voltage sensing available. It would be worth enquiring what the cost etc to have the output voltage dropped back to 13.8v and run a battery terminal sense wire so the alternators regulator senses true battery voltage.
If you choose to stay with the 700Ah battery pack and use Winston or Sinopoly cells you can at a pinch use all 700ah available and still get away with that over 1,000 times acording to the posted tests. To me that's pushing the boundaries a tad too far but they claim 5,000 cycles using 80% of the available capacity so you will have plenty in reserve.
I recommend using as small cells as possible connected in parallel to build the capacity you are looking for, then 4 of these paralleled sets in series to build 12v or 8 to build 24v, depending on the system you choose.

T1 Terry

[ColdEH]

Thanks Terry.

I will call Echo Tec today and ask them what is involved in changing the alternators output voltage set point. I have the sensing wire for the voltage.

What would be the ideal voltage to set it at , 13.6v or 13.8v ? Would I need any other charge controllers in the system , or just build the banks as you describe and wire them up?


Regards

[neelie]

T1 Terry... Many thanks for your advice. I will give it a go. And yes I am in Honkers. I'll start looking for batteries early next week when I get back to town. I will have hundreds of questions as I muddle my way through my own version of LFP101.

Goboatingnow... I agree with your observation about a little knowledge being a dangerous thing. But in the end, there's only one way for me to find out if I am out of my depth or not. I'll give it my best shot, and if I fail... well, I fail not from lack of trying.

[ColdEH]

T1 Terry.

I got a hold of Echo tec alternators, they can change the voltage no problem . I have to send them the regulator or just order a new one .

They are asking what voltage I want them set to. 13.75 or 13.8 volts for charging Sinopoly batteries.

What do you think , what should I have it set to .

Regards .

[T1 Terry]

Originally Posted by typhoon

T1 Terry.

I got a hold of Echo tec alternators, they can change the voltage no problem . I have to send them the regulator or just order a new one .

They are asking what voltage I want them set to. 13.75 or 13.8 volts for charging Sinopoly batteries.

What do you think , what should I have it set to .

Regards .

13.8v will be fine, 13.75v will give you a small reduction in capacity as it won't quite reach fully recharged each cycle, it's not an issue with these type batteries as 100% recharged is not necessary to avoid sulphation like lead acid batteries, there is no acids in these batteries, a different format for energy storage, I won't go into it here as your eyes will roll and you'll fall off your chair :lol:

Grab a coffee, this bit will send you to sleep -There is a theory doing the rounds based on some strong logic that says avoiding fully charging and fully discharging these cells keeps them out of the danger zones and their life could be extended indefinite.... within reason, nothing lasts for ever other than a woman's memory. I tend to believe their theory is based on the old 4v per cell fully charged and 2v fully discharged and these are not actually voltage figures that can be used on their own, there are a lot of other things like charging rate/discharge rate etc connected with the formulae where the 4v and 2v figures were plucked from. I think it dated back to when all the information relating to these batteries was in Chinese, the numbers where the only universally understood language... a little information is just as bad as a little knowledge sometimes and the fact these figures remain on some of the manufacturers data sheets doesn't help, you need to know where the figures fit in.
These cells are fully charged at 3.4v, the extra 0.05v is to ensure even charge distribution throughout all the cells within the pack, low enough to produce even charge distribution without creating heat build up within the cells. Internal heat is what kills these batteries, internal heat generation within a cell happens when the voltages go outside the safety zone, it boils off the electrolyte causing either cathode or anode coating first then loss of conducting fluid, the lithium plates out on which ever electrode and the cell is finished. Damage or destruction of these cells is not instant like some BMS makes claim, it's an accumulative thing, they die slowly when outside their safety zone of 2.8v at the bottom and 3.5v at the top, all the time they are outside these zones they are getting damaged so a short trip outside the zone does little damage, a long stay out there will finally kill them.

Ok, time to wake up again :lol:

T1 Terry

[ebaugh]

Originally Posted by T1 Terry

13.8v will be fine, 13.75v will give you a small reduction in capacity as it won't quite reach fully recharged each cycle, it's not an issue with these type batteries as 100% recharged is not necessary to avoid sulphation like lead acid batteries, there is no acids in these batteries, a different format for energy storage, I won't go into it here as your eyes will roll and you'll fall off your chair :lol:

Grab a coffee, this bit will send you to sleep -There is a theory doing the rounds based on some strong logic that says avoiding fully charging and fully discharging these cells keeps them out of the danger zones and their life could be extended indefinite.... within reason, nothing lasts for ever other than a woman's memory. I tend to believe their theory is based on the old 4v per cell fully charged and 2v fully discharged and these are not actually voltage figures that can be used on their own, there are a lot of other things like charging rate/discharge rate etc connected with the formulae where the 4v and 2v figures were plucked from. I think it dated back to when all the information relating to these batteries was in Chinese, the numbers where the only universally understood language... a little information is just as bad as a little knowledge sometimes and the fact these figures remain on some of the manufacturers data sheets doesn't help, you need to know where the figures fit in.
These cells are fully charged at 3.4v, the extra 0.05v is to ensure even charge distribution throughout all the cells within the pack, low enough to produce even charge distribution without creating heat build up within the cells. Internal heat is what kills these batteries, internal heat generation within a cell happens when the voltages go outside the safety zone, it boils off the electrolyte causing either cathode or anode coating first then loss of conducting fluid, the lithium plates out on which ever electrode and the cell is finished. Damage or destruction of these cells is not instant like some BMS makes claim, it's an accumulative thing, they die slowly when outside their safety zone of 2.8v at the bottom and 3.5v at the top, all the time they are outside these zones they are getting damaged so a short trip outside the zone does little damage, a long stay out there will finally kill them.

Ok, time to wake up again :lol:

T1 Terry

That's all good except "even charge distribution" part...I don't think it's possible to even out the charge until until there are no more electrons to move over in the high cell, and this does not appear to happen until better than 3.45V, the max per cell you want to see. Why with 4 cells I use 3.4 average or 13.6V as the high end target. It does cost me 5% or so in total capacity.

[witzgall]

Terry, are you saying that charging to 14v will damage our cells, even if the amps are low? In my case, our solar charger will top off the batteries at or above 14v (depending on settings). The max it can put out is 15 amps, so less than .04c.

We just installed a new wind gen, which has an external controller, which also controls solar. We already have a 120w panel on the Sunsaver MPPT 15, and this new wind/solar (PWM) will have two, 85w panels. This controller is digitally controllable as to the voltage when it cuts out (brakes wind gen). I don't want them fighting each other, ie the voltage of one cutting out the other. I am thinking to have this cut out at 14.1?

Chris