Opinion on LiFePo4 supplier

[Geoff V]

Gentlemen

I am still looking for a supplier of good LiFePo4 cells and BMS, came across this one, does anybody on ES have experience with, or opinions on their products?

http://www.servovision.com/Battery/Batterry%20LithiumFerrumPhosphate%20LiFePo4%20cell%20aluminium.html

GeoffV

 

[dogman dan]

Looks like nobody ever heard of this one. Ships from Bankok apparently, or at least the office is there. Not that ships from china inspires a lot of trust, but Bankok would inspire less in me.

 

[Geoff V]

dogman

Thank you for your reply, I am a little suprised at the lack of reponse to my thread, it may be as you suggest that this supplier is not well known, yet their website covers a lot of electronics.

Having travelled far and wide I have much respect for the Thai people and am willing to try their products even though the source of their goods is not clear. The appeal of 16 x 12Ah cells arranged in series for use and switched to parallel for charging would remove the need for a BMS leaving only the LVC to be monotored, an engineers solution to an electronic problem!

Will keep the Forum informed if as and when they arrive and have been trialed.

GeoffV

 

[dnmun]

why are you surprised. you only gave a link to a website. no prices, nothing really interesting to comment on. they are not made in thailand, more likely they are made in china. these guys just sell them.

not sure why you think running without a BMS is an engineers solution either. no engineer would do that. you cannot do anything to test them either if you use them without a BMS since you won't be able to discharge them at anything close to their capacity. they will be dead pretty quick.

you never mentioned here how much it cost for these 16 prismatic cells you said you bot. why was that?

you would most likely be better off to buy a pack from ping which is well constructed and has the BMS and charger. building a battery from scratch is not a trivial pursuit.

without a BMS to balance it, well you can read about all the dead batteries built by newbies who think they know everything and can save a buck on a $500 investment by not using a BMS if you wanted to. but why bother.

 

[Cyclebutt]

I looked at the site. Some nice looking battery products. Never did see the prices but no time right now to search. Order and post your results. I'm interested.

 

[Geoff V]

dnmun

I sorry you feel it necessary to respond to my threads with such an agressive attitude which leaves me with the impression that you think you are one of the few people on this Planet that is capable of logical, rational, thought. If there really is 'nothing interesting to comment on' please refrain from commenting.

GeoffV

 

[dnmun]

no, i don't think you understand how hard it is to make a battery work. if you don't use a BMS to keep it balanced then it will die. i feel it is directly misleading to those newbies who think they can just throw something together and then they end up with 3 or 4 dead cells and come here asking how they fix it. then someone tells them they can fix it by using a single cell charger to charge up the low cell, or that they can just charge up the cells without worrying about cells getting overcharged or how they just plug in some cellogs or there is the bottom balancing guy. there is a thread somewhere on here where there is a full glorification of using a pack without using a BMS. like i said you can read all the posts from people who ruined their pack by accident because they had no BMS. like i said an engineer would not build a battery without a BMS to protect it. the entire idea of taking the battery apart to charge it as 8S doesn't change that in any way.

 

[o00scorpion00o]

Those blue cells look rather similar to these on the Golden Motor site!

 

[Geoff V]

scorpion

They sure do look the same, will have to investigate.

thanks

GeoffV

 

[dogman dan]

Yahoo. I just thought if they are made in China, what's the advantage of a Thai dealer? My lack of trust extends to everybody world wide I've never heard of.

We do however have a fairly short list of folks in China that earned our trust.

 

[999zip999]

Maybe a list of vendors not to trust, But could be a little stickie.

 

[dogman dan]

I would say it's morel like a list of many many many sources that pop up on aibaba or whatever, that nobody, or few, have dealt with before. That list of vendors in china woud be very very very long. I never called them "bad vendors". Just unknown folks.

More pop up all the time that are in the USA or other countries as well, and some are good companies while others are shaky garage based, "group buy" category kind of operations. But it's hard to sort em out if you don't know the guy personaly, or have done buisness with em before. In country is of course, usually going to cost more.

My personal trusted vendor list is only for bike size stuff, and is very short. The china based list would be pingbattery, and hobby king. I have bought from them, and am happy with what I got. Emissions free, BMS battery, and others I have not actually done buisness with myself. If I had the cash right now though, I'd be buying an A123 pack from emissions free.

 

[Cyclebutt]

Can someone direct me to a thread where this kind of battery cell has been used in pack builds. I've found one but I'd like to see more. I want to use these in my FIRST pack build. Anything I can glean will help.

 

[dogman dan]

Those you would assemble in a way similar to a ping or other pouch cell pack. So you might do your search based on "replacing cells in a ping" or something like that.

If those cells come with the soldering tabs attached to the pouch tabs, it would then just be a matter of connecting the cells you want to paralell with solder, then flip flopping the cells in the next paralell group to make + to - connetions between the groups of paralelled cells.

Small slotted pcb's with a trace on them make the soldering easier in a ping pack, but I suppose it could be done with a fat wire or copper bar.

 

[dnmun]

you can find a lotta sources on alibaba for those pouch cells. they call them prismatics, but i use prismatic for the cells in the rectangular plastic package.

but if you actually do the numbers, how much they cost and how much it costs to assemble the pack, it turns out that the ping pack is cheaper than buying and assembling it yourself when you add in the cost of all the parts including the BMS and shipping.

and the new cheap guy sun-thing28 is even cheaper than ping using these pouches too. but ping now has his own pouches and i think they may be higher quality than what you will get from alibaba unless the chinese source is high quality. in which case it will be as expensive as ping anyway. they make millions of these in china every day.

 

[Cyclebutt]

My Ping pack has these inside? Never knew that. Then these things aren't all that light after all. I AM happy with the 16.5 aHr run time I get out of my 15 aHr pack. I don't run into cut-off very often but it happens...