Thoughts on cheap Chinese LiFePOs?

[jetzi]

I have an opportunity to buy some discounted but brand new LiFePOs (450 GBP instead of 600 GBP) and I was wondering if anyone had opinions on these units. I still have a lot of research to go but I would need to pull the trigger on these within a week!

 

They are 120Ah, 12V batteries with a similar form factor to LA leisure batteries. They have a built in BMS which keeps them balanced. I'm thinking of paralleling 4 of these to give me 480Ah.

 

Here is a spec sheet.

 

 

[blackrose]

I know nothing about them but £450 for a 120 Ah battery? That's supposed to be cheap?

 

A 12v Trojan can be had for £150 for 150 Ah. Those "cheap" Chinese lithium ion batteries would need to last a long time to make economic sense.

Edited November 9, 2019 by blackrose

[The Welsh Cruiser]

31 minutes ago, blackrose said:

I know nothing about them but £450 for a 120 Ah battery? That's supposed to be cheap?

 

A 12v Trojan can be had for £150 for 150 Ah. Those "cheap" Chinese lithium ion batteries would need to last a long time to make economic sense.

Are you sure about the Trojan price? I paid £125 for a 105AH 12v 3 years ago. Checked a couple of weeks ago, £175 for the same thing now. Hell of an increase.

[Dr Bob]

£1800 for 4 is a bit steep when you can get 4 * 2nd hand Winstons for £1000.

Have you read the Marine How To site. (The bit about 'drop ins' is near the top)

https://marinehowto.com/lifepo4-batteries-on-boats/

on cheap Chinese Li's?

I don't know if these fit into that category but if they do I would give them a wide berth. I do worry about the mechanical strength if you have hundreds of tiny cells. 

The BMS will only help you with balancing so you will still need all the auto disconnect stuff.

Have you any more info on the construction of them or what the BMS is claimed to do? 

With hundreds of tiny cells you will not be able to measure cell voltage when charging to near 100% SoC and have to rely on the batteries internal control system. Peter has the multi cell type battery but from a very reputable supplier and he never goes near 100%. I prefer the 12 big cells in a 3p 4s configuration as you can see and control cell voltage which I think is important in a DIY system if you are going up to 100%. If you went down this route, you would be going in a direction no one has been down to date ......apart from on the marine how to site. 

[rusty69]

I know little about lithium batteries, but was reading this much quoted website today. I am sure you are familiar with it:-

Quote

“Lead-Acid Equivalent” Lithium Batteries

There is a growing offering from numerous obscure brands for direct “lead-acid replacement” lithium batteries. Those are often assembled from a large number of small cylindrical cells complemented with an over-voltage/under-voltage protection circuit and a crude cell balancing scheme. They are small-size, cheap, self-contained and often poorly executed versions of the battery systems mentioned above. They are almost invariably advertised with charging voltages as high as 14.4-14.6V (and now 14.8V as of 2018!), which would quickly damage the cells: nothing within the battery can possibly do anything about the charging voltage being excessive, for too long etc. The high-voltage protection is always set far too high in order to allow connecting them to any automotive system without tripping it: it just has to be. It is a “catastrophic failure protection” only, it won’t prevent ruining the cells gradually. If the high-voltage protection trips, it will open the charging circuit and destroy the alternator if the engine is running: this is the only thing it can do! As long as the charge and discharge currents are within the capability of the disconnect relay, as a single unit, such a battery could perform acceptably on an installation where charging voltages have been adjusted suitably low not to stress lithium cells. In this case, the balancing circuit will never manage to operate. They are generally not suitable for installation in parallel for building larger systems, because this equates to paralleling strings of cells, even current distribution cannot be preserved and there is a risk of burning out the protection relays. Some of these “replacement” packaged batteries have continuous current ratings as low as 30A… because high-current disconnect relays are expensive. These issues around the adequacy of the protection system don’t always arise however: sometimes there is simply none built-in!

http://nordkyndesign.com/from-lead-acid-to-lithium-new-battery-technology-for-power-on-board/

 

 

I would be asking why most adopters of lithium on this forum have opted for the individual cell method with associated cell monitoring before pressing that buy button.

 

I would also like to adopt Lithium, but I believe a large amount of knowledge and a clear plan of how it will integrate with existing charging equipment and necessary low and high voltage protection is required before any buying commences.

 

That "bargain" can quickly turn into an expensive mistake unless you fully understand the requirements imo.

 

At the very least, I would request a data sheet for the battery in question to try and learn more about the inbuilt BMS and charging requirements.

 

Good luck.

 

Eta. Beaten by a muppet. I shall go back to sleep. 

 

Time for bed....... Boing. 

Edited November 9, 2019 by rusty69

[bizzard]

Chineese rithium batterly notch top.

[dmr]

My son uses "knockoff" lithiums in his various Makita tools. Last week one spontaneously exploded. My daughter was home and after a big struggle just managed to put the fire out. She was just leaving for work so ten minutes later they would have lost the house.

These are small 18 volt 3 amp-hour batteries, just think what 100 amp hours could do. Stick to well known brands?

 

......................Dave

[Alan de Enfield]

27 minutes ago, dmr said:

My son uses "knockoff" lithiums in his various Makita tools. Last week one spontaneously exploded. My daughter was home and after a big struggle just managed to put the fire out. She was just leaving for work so ten minutes later they would have lost the house.

These are small 18 volt 3 amp-hour batteries, just think what 100 amp hours could do. Stick to well known brands?

 

......................Dave

A timely reminder to us all - "you get what you pay for"

 

Stay safe, Live long & Prosper !!

[Athy]

If their manufacturing quality control is as stringent as their monitoring of whoever does their English translations, they should be avoided.

[Slim]

32 minutes ago, Athy said:

If their manufacturing quality control is as stringent as their monitoring of whoever does their English translations, they should be avoided.

In this day and age it's impossible to avoid buying Chinese. The saloon version of my Volvo V90 is built in China. ?

I know nothing about Lithium batteries or the technology contained therein. However, if I'm offered a battery that a budget supplier , in this case Sterling, want £1500 for, at £450 thw warning bells would be ringing very loud.

 

[MtB]

10 hours ago, The Welsh Cruiser said:

Are you sure about the Trojan price? I paid £125 for a 105AH 12v 3 years ago. Checked a couple of weeks ago, £175 for the same thing now. Hell of an increase.

 

Well the Trojans are imported and the value of the £ has dropped 20% in the last three years. 

 

I have no idea why that could have happened.... 

[MtB]

8 minutes ago, Slim said:

In this day and age it's impossible to avoid buying Chinese. The saloon version of my Volvo V90 is built in China. ?

I know nothing about Lithium batteries or the technology contained therein. However, if I'm offered a battery that a budget supplier , in this case Sterling, want £1500 for, at £450 thw warning bells would be ringing very loud.

 

 

The Chinese manufacture is not the root of the problem, I'd be amazed if a lot of the content of Victron stuff is not Chinese.

 

 It is the quality control you get with branded stuff that the higher price is paying for. A subtle point normally overlooked by people who are "buying the price" as they say in the world of selling.  

 

 

[Athy]

6 minutes ago, Mike the Boilerman said:

 

Well the Trojans are imported and the value of the £ has dropped 20% in the last three years. 

 

I have no idea why that could have happened.... 

I've given up trying to understand it. I thought that the currency markets liked safety and stability; yet here we are, still not really knowing when we shall leave the EU, and with the uncertainly of a general election impending - yet we get more euros for our pounds now than we did at the beginning of the year. As a character in the Dandy (or was it the Beano?) used to say, "Daft, I call it".

[Dr Bob]

10 hours ago, rusty69 said:

I know little about lithium batteries, but was reading this much quoted website today. I am sure you are familiar with it:-

http://nordkyndesign.com/from-lead-acid-to-lithium-new-battery-technology-for-power-on-board/

 

 

I would be asking why most adopters of lithium on this forum have opted for the individual cell method with associated cell monitoring before pressing that buy button.

 

I would also like to adopt Lithium, but I believe a large amount of knowledge and a clear plan of how it will integrate with existing charging equipment and necessary low and high voltage protection is required before any buying commences.

 

That "bargain" can quickly turn into an expensive mistake unless you fully understand the requirements imo.

 

At the very least, I would request a data sheet for the battery in question to try and learn more about the inbuilt BMS and charging requirements.

 

Good luck.

 

Eta. Beaten by a muppet. I shall go back to sleep. 

 

Time for bed....... Boing. 

Yea, but you said it better than me!

10 hours ago, dmr said:

My son uses "knockoff" lithiums in his various Makita tools. Last week one spontaneously exploded. My daughter was home and after a big struggle just managed to put the fire out. She was just leaving for work so ten minutes later they would have lost the house.

These are small 18 volt 3 amp-hour batteries, just think what 100 amp hours could do. Stick to well known brands?

 

......................Dave

The point on 'cheap' is very well made but the explosion was a function of the chemistry. For botes we are talking LiFePO4s which are much safer and are very difficult to set on fire. Cheap batteries are dangerous.

30 minutes ago, Slim said:

In this day and age it's impossible to avoid buying Chinese. The saloon version of my Volvo V90 is built in China. ?

I know nothing about Lithium batteries or the technology contained therein. However, if I'm offered a battery that a budget supplier , in this case Sterling, want £1500 for, at £450 thw warning bells would be ringing very loud.

 

Most Li's come from China. The Winston thunderskys are Chinese. It is the cheapo models you must avoid and particularly the 'drop in' ones which are just not built to the same standards. 

[Chewbacka]

21 minutes ago, Athy said:

I've given up trying to understand it. I thought that the currency markets liked safety and stability; yet here we are, still not really knowing when we shall leave the EU, and with the uncertainly of a general election impending - yet we get more euros for our pounds now than we did at the beginning of the year. As a character in the Dandy (or was it the Beano?) used to say, "Daft, I call it".

That’s because the currency traders are expecting Boris to win and then leave with his deal.  If you think that Labour is going to win, then probably best you buy next years holiday Euros before the traders agree with you.........

[Richard10002]

14 hours ago, ivan&alice said:

I have an opportunity to buy some discounted but brand new LiFePOs (450 GBP instead of 600 GBP) and I was wondering if anyone had opinions on these units. I still have a lot of research to go but I would need to pull the trigger on these within a week!

I am thinking of LiFePO4 and am closer to buying new cells, rather than "drop ins".

 

As an example I can buy Sinopoly cells from Amazon, from a distributor in Prague, and direct from China. My guess is that they are the same batteries, from the same place, but at quote different prices.

 

From the distributor in Prague:

 

https://www.ev-power.eu/LiFePO4-small-cells/SP-LFP100AHA-Lithium-Cell-LiFePO4-3-2V-100Ah.html?cur=1

 

about £1500 for 300Ah when you add the bits to connect them and a BMS.

 

From Amazon with a 2-3 week dispatch time, so probably direct from either Prague, or China:

 

https://www.amazon.co.uk/LiFePO4-Lithium-Phosphate-Off-Grid-Applications/dp/B07VH2JJWG/ref=pd_rhf_se_p_img_3?_encoding=UTF8&refRID=PH83W95W2QA4ENC7MBXB&th=1

 

about £2000 for 300Ah when you add a BMS

 

Direct from RUIXU in China:

 

https://www.ruixulithiumbattery.com/lithium-iron-phosphate-battery-12v-100ah-without-bms

 

About £1000, presumably plus shipping, duty, VAT, customs clearance.... then plus a BMS.

 

If buying, I would probably take a chance on GWL in Prague.

[Nut]

you get what you pay for tread carefully

[Dr Bob]

17 minutes ago, Richard10002 said:

I am thinking of LiFePO4 and am closer to buying new cells, rather than "drop ins".

 

As an example I can buy Sinopoly cells from Amazon, from a distributor in Prague, and direct from China. My guess is that they are the same batteries, from the same place, but at quote different prices.

 

From the distributor in Prague:

 

https://www.ev-power.eu/LiFePO4-small-cells/SP-LFP100AHA-Lithium-Cell-LiFePO4-3-2V-100Ah.html?cur=1

 

about £1500 for 300Ah when you add the bits to connect them and a BMS.

 

From Amazon with a 2-3 week dispatch time, so probably direct from either Prague, or China:

 

https://www.amazon.co.uk/LiFePO4-Lithium-Phosphate-Off-Grid-Applications/dp/B07VH2JJWG/ref=pd_rhf_se_p_img_3?_encoding=UTF8&refRID=PH83W95W2QA4ENC7MBXB&th=1

 

about £2000 for 300Ah when you add a BMS

 

Direct from RUIXU in China:

 

https://www.ruixulithiumbattery.com/lithium-iron-phosphate-battery-12v-100ah-without-bms

 

About £1000, presumably plus shipping, duty, VAT, customs clearance.... then plus a BMS.

 

If buying, I would probably take a chance on GWL in Prague.

 

10 minutes ago, Nut said:

you get what you pay for tread carefully

 

 

The Sinopoly cells Richard is looking at are a premium make and should be excellent quality. They are single cells so the individual cell voltages can be monitored unlike the ones that Ivan was looking at. I would have no hesitation buying the Sinopoly cells if I wanted new ones rather than 2nd hand as they look the cheapest around. I would sooner get 2nd hand ones though as they are much cheaper and should last a long time on a bote. The more you pay, the more you need to make sure you dont screw up!!

Richard, if you get these, make sure you assemble them together with supporting metal straps so they dont bulge or expand during use. The ones I got were supplied already strapped and mostly balanced. These probably will  require balancing ...by wiring all in parallel and charging to 3.6V and then leaving for a day and recharging again, before reassembling in their 3P 4S config. If you get them from Amazon, they come with all the interconnect fittings. Make sure you order these if you dont get them from Amazon.

[rusty69]

There was a magazine article on LiFePo4 batteries recently, worth a read. Actually on second thoughts,its probably a topic worthy of its own thread........skuttles off to start a new thread.

Edited November 10, 2019 by rusty69

[Richard10002]

3 hours ago, Nut said:

you get what you pay for tread carefully

You won’t believe how carefully I’m treading  Which is why I haven’t pressed the button yet.

 

Considering a few options.

 

I posted mainly to show Ivan an alternative to the battery he posted about, from 3 sources in the distribution chain.

[Detling]

Also need to check shipping. They are too big Ah for air (100aH max) so will need sea transport, customs duties could be an unknown with Brexit around.

[Richard10002]

7 minutes ago, Detling said:

Also need to check shipping. They are too big Ah for air (100aH max) so will need sea transport, customs duties could be an unknown with Brexit around.

They come from Prague by TNT truck. Given that we won’t be leaving the EU, (if we do), before the election, there is a bit of time to play with.

[rusty69]

4 hours ago, Richard10002 said:

They come from Prague by TNT truck. Given that we won’t be leaving the EU, (if we do), before the election, there is a bit of time to play with.

My god, isn't that a tad dangerous. If they combine, they would produce Trinitrotolithium (TNTLIT). The resulting explosion would blow the UK a thousand miles into the atlantic, away form Europe and closer to the USA.

[Dr Bob]

1 hour ago, rusty69 said:

My god, isn't that a tad dangerous. If they combine, they would produce Trinitrotolithium (TNTLIT). The resulting explosion would blow the UK a thousand miles into the atlantic, away form Europe and closer to the USA.

.....and if they sent out two trucks at the same time it would be Trinitro-dilithium which would be even worse! Thats one way to get out of Europe.

[jetzi]

On 09/11/2019 at 22:32, blackrose said:

I know nothing about them but £450 for a 120 Ah battery? That's supposed to be cheap?

 

A 12v Trojan can be had for £150 for 150 Ah. Those "cheap" Chinese lithium ion batteries would need to last a long time to make economic sense.

LiFePO4s will definitely last at least 3x as long as a LA. Even if they didn't, the Li's numerous other advantages could still conspire to make them better value than LAs (such as in reduced engine running).

 

On 09/11/2019 at 23:09, Dr Bob said:

£1800 for 4 is a bit steep when you can get 4 * 2nd hand Winstons for £1000.

For a start, these are new, so it's not fair to compare them to 2nd hand, but also I'm not sure I can get 4x 2nd hand Winstons for 1kGBP. That's going to depend on availability, surely? Or do you know a reliable source of 2nd hand LiFePOs?

 

On 09/11/2019 at 23:09, Dr Bob said:

Have you read the Marine How To site. (The bit about 'drop ins' is near the top)

https://marinehowto.com/lifepo4-batteries-on-boats/

on cheap Chinese Li's?

I don't know if these fit into that category but if they do I would give them a wide berth. I do worry about the mechanical strength if you have hundreds of tiny cells. The BMS will only help you with balancing so you will still need all the auto disconnect stuff.
Have you any more info on the construction of them or what the BMS is claimed to do? 

These aren't drop-ins by the definition of the Marine How To site. Supposedly they can interface with a more advanced management system. I don't know about the internal structure of these (whether they made up of 4x large 3.2V cells in series, or inside each unit are there 4x internal 3.2V batteries each with numerous small cells in parallel). I have sent a message to ask. My guess would be larger cells, simply because that would be easier to design a BMS for. Apparently the internal BMS balances the battery internally, has a low temperature charge cutoff at 0 degrees and a discharge cutoff between -20 and 60 degrees, and can communicate with an external monitor. I've asked for more details about the BMS.

 

On 09/11/2019 at 23:09, Dr Bob said:

With hundreds of tiny cells you will not be able to measure cell voltage when charging to near 100% SoC and have to rely on the batteries internal control system. Peter has the multi cell type battery but from a very reputable supplier and he never goes near 100%. I prefer the 12 big cells in a 3p 4s configuration as you can see and control cell voltage which I think is important in a DIY system if you are going up to 100%.

I plan to follow the 80%/20% pattern, at least until I have a good understanding of my batteries and how they behave. I would prefer having big cells myself, lets see what the manufacturer says about the internal construction.

 

On 09/11/2019 at 23:20, rusty69 said:

nothing within the battery can possibly do anything about the charging voltage being excessive, for too long etc. The high-voltage protection is always set far too high in order to allow connecting them to any automotive system without tripping it: it just has to be. It is a “catastrophic failure protection” only, it won’t prevent ruining the cells gradually. If the high-voltage protection trips, it will open the charging circuit and destroy the alternator if the engine is running: this is the only thing it can do!

I would not be using these as drop-ins, in the sense that I would definitely still need a charging system including cutoffs, dump loads, etc. I'm talking about using these only for the capacity. The internal BMS is almost an unfortunate addition - or at least something I would have to figure out how to work with/around.

 

On 09/11/2019 at 23:20, rusty69 said:

a clear plan of how it will integrate with existing charging equipment and necessary low and high voltage protection is required before any buying commences

I agree. It's a timing thing - I have this opportunity now and perhaps not later. I don't have any existing equipment so it's more about what is the ideal equipment. I'm leaning towards a lot more research though.

 

On 09/11/2019 at 23:30, dmr said:

My son uses "knockoff" lithiums in his various Makita tools. Last week one spontaneously exploded. My daughter was home and after a big struggle just managed to put the fire out. She was just leaving for work so ten minutes later they would have lost the house.

These are small 18 volt 3 amp-hour batteries, just think what 100 amp hours could do. Stick to well known brands?

LiFePOs are a different technology though, they are very stable.

 

On 10/11/2019 at 12:30, Richard10002 said:

I am thinking of LiFePO4 and am closer to buying new cells, rather than "drop ins".

 

As an example I can buy Sinopoly cells from Amazon, from a distributor in Prague, and direct from China. My guess is that they are the same batteries, from the same place, but at quote different prices.

It's good to see these alternatives. They work out a bit more expensive per Ah but I really like the name brand and the individual cells. Thanks for the tip.

 

Would love to consider second hand but I really don't know where to begin looking for them or how to judge the quality of them. Add it to the reading list I guess!!

 

Thanks all for the advice, I'm going to wait to hear the answers to the quetions but I am leaning towards taking it slow.