Experience of TN-Power LiFeP04 Batteries

[m6North]

Hi All,

I was just wondering if anyone has any experience with the TN-Power Lithium batteries, I realise they're pretty new to the market but I can't find any testimonials / reviews anywhere.

They seem like an interesting proposition but am concerned they might be too good to be true?

Any thoughts?

[nicknorman]

Hmmmm where to start...

 

Lithium batteries are great in principle, but they are not the same as Lead Acid (LA) batteries and if you treat them as if they were, problems are likely to arise.

 

These type of “drop in LA replacement” batteries seem like a good idea because they have a built in BMS (Battery Management System) that is claimed to protect the cells from over or under discharge or other abuses. But you are paying a lot more to have this integrated system vs bare lithium cells and separate BMS.

 

If you are planning to use it as a drop in replacement for LA bear in mind the following:

 

According to the spec, only 2 batteries in parallel are permitted. This limits the max size of the bank.

 

The charging spec says charge to 14.6v limiting current to 0.2 capacity, then stop charging when current falls below 0.02C. Implicit in that is that you stop charging at that point, you do not continue to charge at 14.6v for the rest of your day’s cruise as you would with LA. If you hold the voltage at 14.6v for hours after it is charged, you will seriously shorten the battery life.

 

Nominal charge current for a 110Ah battery is 26A, max 54A so if you have a big alternator you will stuff too much current into it and damage it.

 

The integral BMS has electronic switching to isolate the battery in the event of abuse, but that electronic switching limits the maximum discharge current to 100A (for the 110Ah) and a nominal current of 0.2C (26A). The battery itself is capable of putting out much more current, the BMS is the limitation.

 

These drop on replacement cells seem to have a bit of a bad name in yachty world because if you treat them like a LA, they don’t last long and are incredibly expensive. If you treat them correctly, they are great.

 

This is why most people on here have gone for separate cells and cobbled together some home made systems with various bits from eBay or home made. Not for the electrically ignorant!

[nicknorman]

Just on the price thing, I’ve just ordered 600Ah at 12v of Li cells from China. It was about £1800. Although I am making my own control / BMS system even if you bought BMS stuff from eBay etc I doubt it would be more that say £400 so £2200 for the system. The equivalent from TN would be £4600 (for 640Ah)

[BEngo]

There are several peeps on here with real life experience of LiFe  batteries.  There is a Big thread on Li battery management.  Dr Bob, Ivan and Alice, Moomin Papa and Peterboat et al have all contributed.  Read that thread and ask yourself "How will my TN batteries tackle all those  issues, particularly the battery killers?" If you then think they will do, go ahead.

 

IMO, and as Nick implies, there is no real "drop in" replacement for LA batteries, except LA batteries. I have not yet found an easy way to make the necessary changes to the battery charging and protection kit so that LiFe batteries will survive long enough to deliver 

That is why I have not yet bought what I believe is a better battery for boat use.

 

N

[m6North]

OK Great, I will check the other thread out - you've both made super helpful points, thankyou!
 

[nicknorman]

 

[Richard10002]

16 minutes ago, BEngo said:

There are several peeps on here with real life experience of LiFe  batteries.  There is a Big thread on Li battery management.  Dr Bob, Ivan and Alice, Moomin Papa and Peterboat et al have all contributed.  Read that thread and ask yourself "How will my TN batteries tackle all those  issues, particularly the battery killers?" If you then think they will do, go ahead.

 

IMO, and as Nick implies, there is no real "drop in" replacement for LA batteries, except LA batteries. I have not yet found an easy way to make the necessary changes to the battery charging and protection kit so that LiFe batteries will survive long enough to deliver 

That is why I have not yet bought what I believe is a better battery for boat use.

 

N

The batteries that peterboat and I have are “drop in” batteries, albeit second hand when we bought them. With some minimal care and precautions, they have been working great for me since November, and for Peter for some years.

 

Whilst they have a “built in” monitoring system, it provides no protection against overcharging or discharging, nor over or under temperature operation, but fairly straightforward to provide active protection externally.

 

Having said that, I don’t think I would be paying £700 for a 100Ah Battery.

[nicknorman]

Mrs melly is desperate to say “Do you have any idea how many candles you can buy for one Li battery?!” but she is too shy to come out and say it. And anyway her carrier pigeon needs a rest.

[DaveP]

I bought a pair of the TN 100ah's in May.  They are not connected to the alternator or other batteries.  Very happy so far.  Altered the programming on the solar controller to charge to 14.6v, hold for 20min, then float at 13.8v, and no boost/equalise on the 28th of the month (Tracer mppt).  I have charged them from a gennie with a dumb charger that put 20ah in an hour - this was to test whether the gennie and charger would withstand the power.  I was thinking of attaching a sterling 30a B2B charger, but won't bother now (come winter I double my panels up and switch off the fridge).

 

Switching from leadacids is a learning experience, and a coulomb counter is necessary to judge what you've got left in the piles....

 

I got them off battery megastore on eBay.  They have an ad for a single item at £700, but a pair attracts 25% discount - this is different to the one for a pair of them!

 

Dave

[mrsmelly]

2 hours ago, nicknorman said:

Mrs melly is desperate to say “Do you have any idea how many candles you can buy for one Li battery?!” but she is too shy to come out and say it. And anyway her carrier pigeon needs a rest.

Nope. The op asked for people with experience of certain batteries and I don't and never will. Paying out hundreds of times more to do a job my flas do admirably is never going to be on my bucket list. 

[nicknorman]

1 hour ago, mrsmelly said:

Nope. The op asked for people with experience of certain batteries and I don't and never will. Paying out hundreds of times more to do a job my flas do admirably is never going to be on my bucket list. 

Well no, lets say 4 x 110Ah at £80 each (cheap!) = £320. By your previous comments, replace every 2 years. So after 10 years = £1600. Which is more than the equivalent Li cells would cost, and they will last a lot longer than 10 years.

 

And in the mean time, no endless generator or engine running to fully charge your LA batteries to ward off sulphation. Li batteries charge at max rate right up until the are very nearly fully charged, and anyway there is no need to fully charge them. So a lot of fuel and irritating noise and engine capital cost is saved. And no need for 4 visits to the shop and scrappy, lugging heavy batteries in and out of the boat.

 

But I appreciate some people just don’t like change. How is Percy the pigeon anyway? Well rested now I hope.

Edited August 19, 2020 by nicknorman

[m6North]

56 minutes ago, nicknorman said:

 

And in the mean time, no endless generator or engine running to fully charge your LA batteries to ward off sulphation. Li batteries charge at max rate right up until the are very nearly fully charged, and anyway there is no need to fully charge them. So a lot of fuel and irritating noise and engine capital cost is saved. And no need for 4 visits to the shop and scrappy, lugging heavy batteries in and out of the boat.

This was our thinking, obviously alot to learn - but we are hopeful that as we're new to boating we could get set up with Li batteries and not pick up some of the bad habits that could be transfered over from having used LA.

Keen to do things in a way that makes sense and not just the way they have always been done.

[mrsmelly]

1 hour ago, nicknorman said:

Well no, lets say 4 x 110Ah at £80 each (cheap!) = £320. By your previous comments, replace every 2 years. So after 10 years = £1600. Which is more than the equivalent Li cells would cost, and they will last a lot longer than 10 years.

 

And in the mean time, no endless generator or engine running to fully charge your LA batteries to ward off sulphation. Li batteries charge at max rate right up until the are very nearly fully charged, and anyway there is no need to fully charge them. So a lot of fuel and irritating noise and engine capital cost is saved. And no need for 4 visits to the shop and scrappy, lugging heavy batteries in and out of the boat.

 

But I appreciate some people just don’t like change. How is Percy the pigeon anyway? Well rested now I hope.

Wrong nick again. No endless charging we are either on hook up or ccing as in moving which charges the batteries so no generater either. It's not only the ludicrous cost it's the fact they can't even be fitted where my flas are. Also having to keep any one boat for at least ten years to break even or modify yet another boat on moving them makes no sense whatsoever. The wheel doesn't need reinventing and kiss deffo applies to batteries. Blow your money on whatever you like but like the other 99.9 percent of boaters my money is staying with flas. 

[peterboat]

19 hours ago, m6North said:

Hi All,

I was just wondering if anyone has any experience with the TN-Power Lithium batteries, I realise they're pretty new to the market but I can't find any testimonials / reviews anywhere.

They seem like an interesting proposition but am concerned they might be too good to be true?

Any thoughts?

James from London has some valence batteries for sale seconhand decent price low cycles and they have a built in BMS I have had them for years work well

[Dr Bob]

12 hours ago, mrsmelly said:

Wrong nick again. No endless charging we are either on hook up or ccing as in moving which charges the batteries so no generater either. It's not only the ludicrous cost it's the fact they can't even be fitted where my flas are. Also having to keep any one boat for at least ten years to break even or modify yet another boat on moving them makes no sense whatsoever. The wheel doesn't need reinventing and kiss deffo applies to batteries. Blow your money on whatever you like but like the other 99.9 percent of boaters my money is staying with flas. 

After 18 months with Li's, I would never dream of going back to LAs. It's the reduction in engine running that is the reason I am so pro Li's.

The problem with 'drop ins' seems to be the rating of some of the internal components .....i.e. The rating of the main isolating switch may only be 50A on some of the cheap units and it sounds like the case in the OPs note if there is a limit on how many you can put in parallel. The 'Marine know how' site has a big section on why not to use drop ins. Peter and Richard are using good drop ins which don't suffer this problem. 

The price quoted by to OP is just crazy. Contact Peter's mate, they are on the top side of acceptable price but likely the best used cells you will get. Nowt  wrong with used Li's. In the 18 month I've been using mine (previously used in an ev) the charge/discharge behavior has not changed at all...and I've been looking closely at it! Narrowboats usage is easy compared to an ev.

My 480Ahrs cost £1000 plus say £500 for the control system (off the shelf) so £1500..... which is far cheaper than LAs when you factor in the reduction in engine hours over a 5 year period.

[Dr Bob]

13 hours ago, mrsmelly said:

 Also having to keep any one boat for at least ten years to break even or modify yet another boat on moving them makes no sense whatsoever. 

I fully agree with this, which is why I put my Li's in parallel with my domestic LAs. Very simple to take off a boat. That's exactly what we have just done. Sold a boat, took the Li's off leaving the existing LAs in place and put the Li's on the new one again in parallel to the installed LAs. 

Another advantage of this hybrid system is that you don't mess around with the existing batteries so installation can be done without loosing power for a day or more....and you don't need to know where all the existing wires go!!!!

[mrsmelly]

29 minutes ago, Dr Bob said:

After 18 months with Li's, I would never dream of going back to LAs. It's the reduction in engine running that is the reason I am so pro Li's.

The problem with 'drop ins' seems to be the rating of some of the internal components .....i.e. The rating of the main isolating switch may only be 50A on some of the cheap units and it sounds like the case in the OPs note if there is a limit on how many you can put in parallel. The 'Marine know how' site has a big section on why not to use drop ins. Peter and Richard are using good drop ins which don't suffer this problem. 

The price quoted by to OP is just crazy. Contact Peter's mate, they are on the top side of acceptable price but likely the best used cells you will get. Nowt  wrong with used Li's. In the 18 month I've been using mine (previously used in an ev) the charge/discharge behavior has not changed at all...and I've been looking closely at it! Narrowboats usage is easy compared to an ev.

My 480Ahrs cost £1000 plus say £500 for the control system (off the shelf) so £1500..... which is far cheaper than LAs when you factor in the reduction in engine hours over a 5 year period.

I think you may be right with some boaters useage. However for mine which is either plugged in so batteries become immaterial or we like year before last are ccing as in moving every day so the batteries get charged anyway. Maybe for someone on a permanent mooring without hook up they would pay for them selves but for me it would just be a waste of effort and money. No two boaters have the same use of batteries, even full timers not on hook up use different amounts of leccy for differing lifestyles. Some people even buy fully electric cars but I dont tend to park up in motorway service stations each time I visit my kids in Cornwall for ages charging my batteries 

[Dr Bob]

9 minutes ago, mrsmelly said:

I think you may be right with some boaters useage. However for mine which is either plugged in so batteries become immaterial or we like year before last are ccing as in moving every day so the batteries get charged anyway. Maybe for someone on a permanent mooring without hook up they would pay for them selves but for me it would just be a waste of effort and money. No two boaters have the same use of batteries, even full timers not on hook up use different amounts of leccy for differing lifestyles. Some people even buy fully electric cars but I dont tend to park up in motorway service stations each time I visit my kids in Cornwall for ages charging my batteries 

You are of course right. Everyone's use is different.

We use circa 160Ahr each day - so the batteries are down by 160Ahrs each morning and that needs to be put back in. On our new boat with 480Ahr of AGMs we were finding that we needed at least 4 hours of running the engine to get back to full. That then is fine if you are CCing and doing 4 hours a day. That is with a big alterntor...but the problem with LAs is that the hours needed to charge are largely in the period when the batteries are controlling the charge. Yes our 240A alternator was good for the first hour but then the reducing tail current sets in. With the Li's now set up and charging at 90A, we replenish our power in 2 hours so that halves the engine running. In the winter we will be on shore power above 50% of the time but when out we can park up and just run the engine 2 hours a day.....or maybe 1 hour a day if I use bigger wires between the batteries and the Combi!!! Li's would be very good for peeps who park up for days on end who use a bit of power. Prolly no use for peeps who are camping!

I love my electric car. It drives down the motorway on its own!!!!! (on lasts nights Beeb news!)

[dingo]

I bought a pair of the TN 100ah's in 2020. It's almost the end of 2022 now and their performance has dramatically decreased. The significant decrease in performance seemed to happen rather suddenly.

They have always been connected to charge via sterling split charge and solar. The programming on the solar controller has always been set as default which i recently found out was to charge to 14.6v, which is over the max charge stated on the battery (14.4v). Maybe this had something to do with it? 

I have now changed the programming to custom and set the max charge to 14v. 

[rusty69]

36 minutes ago, dingo said:

I bought a pair of the TN 100ah's in 2020. It's almost the end of 2022 now and their performance has dramatically decreased. The significant decrease in performance seemed to happen rather suddenly.

They have always been connected to charge via sterling split charge and solar. The programming on the solar controller has always been set as default which i recently found out was to charge to 14.6v, which is over the max charge stated on the battery (14.4v). Maybe this had something to do with it? 

I have now changed the programming to custom and set the max charge to 14v. 

See post #2. 14.6 V may be ok if you followed the subsequent instructions. Did you?

 

Are they the ones in the attache data sheet?

 

Quote

 

The charging spec says charge to 14.6v limiting current to 0.2 capacity, then stop charging when current falls below 0.02C. Implicit in that is that you stop charging at that point, you do not continue to charge at 14.6v for the rest of your day’s cruise as you would with LA. If you hold the voltage at 14.6v for hours after it is charged, you will seriously shorten the battery life.

 

TN-LFP12.8V100 V2.1 (1).pdf

Edited December 3, 2022 by rusty69

[dingo]

2 minutes ago, rusty69 said:

See post #2. 14.6 V may be ok if you followed the subsequent instructions. Did you?

 

 

Nope - I was told that the solar controller would automatically detect the tn batteries and automatically set the programming to suit so I didn't check anything when i first connected them. 

The voltage drop is massive now, especially when i try to run my water heater. The water heater works 100% of the time if i have the split charge turned on. If the split charge isn't on the draw is too much most of the time so the water heater doesn't kick in properly and then shuts off. 

The batteries are still useable, just performance is nothing like they were.     

[rusty69]

Just now, dingo said:

Nope - I was told that the solar controller would automatically detect the tn batteries and automatically set the programming to suit so I didn't check anything when i first connected them. 

The voltage drop is massive now, especially when i try to run my water heater. The water heater works 100% of the time if i have the split charge turned on. If the split charge isn't on the draw is too much most of the time so the water heater doesn't kick in properly and then shuts off. 

The batteries are still useable, just performance is nothing like they were.     

Which solar controller have you got?

How are you measuring the voltage (apart from the water pump running)?

[dingo]

I have the Epever Tracer, what are you using? 

[rusty69]

1 minute ago, dingo said:

I have the Epever Tracer, what are you using? 

Then unless you have modified the settings to 'user'with an MT50 meter or bluetooth device, it is likely that they are set to a lead acid charging profile.Are you able to check what it is set to?

 

The other question is how are you regulating the charge to the lithium batteries from your engine alternator and other charging sources.

 

 

Also, what are the BMS parameters set to?

[dingo]

Wow you're good! That is correct, they were set to lead acid charging profile. 

With the drop in performance i started to investigate which is when i noticed the programming was wrong on the MT50. i have since set the programming to custom as i cannot see an option for lithium. 

I'm thinking when i come to replace the batteries i should probably look at replacing the solar controller.