Lifepo4 battery too cheap?

[n-baj]

Hello all, 

 

I'm planning to drag my DC system into the 21st century this summer and been researching lifepo4 for a while now. 
 

I was thinking of going for Sterling’s batteries but I’ve come across fogstar’s batteries currently on pre-order;

 

https://www.fogstar.co.uk/collections/lithium-leisure-battery/products/fogstar-drift-460ah-leisure-battery
 

I’m a little suspicious at the price (£1240 for 460ah and it’s heated) it seems too low to me? I believe cheap lifepo4 batteries use lower grade cells although they say they use grade A. I’m wondering what the lifepo4 experts think? 

also I know about the potential pitfalls of this battery chemistry (melting alternators, etc) and if this post looks like a shill post, it isn’t. I have no relationship with this company, just a potential lithium convert (I’ve seen Tony1’s set up last year) :)

 

many thanks,

 

R

 

 

 

 

[rusty69]

Also worth considering these people. They are a bit pricier but have a good following in the 12v facebook group:

 

https://www.lifebatteries.co.uk/shop

 

There was talk a while back about the fogstar BMS not being user configurable without invalidating the 10 year warranty (think the life batteries is 5), but when I chatted to fogstar, they seemed ok with it. Best to check first. There was also a discrepancy in the weight difference between the products, which I never really solved.

 

 

[n-baj]

9 minutes ago, rusty69 said:

Also worth considering these people. They are a bit pricier but have a good following in the 12v facebook group:

 

https://www.lifebatteries.co.uk/shop

 

There was talk a while back about the fogstar BMS not being user configurable without invalidating the 10 year warranty (think the life batteries is 5), but when I chatted to fogstar, they seemed ok with it. Best to check first. There was also a discrepancy in the weight difference between the products, which I never really solved.

 

 

Thanks for the link rusty, just taken a quick look. Yes there is a weight difference alright! Fogstar 300ah is 8.5kg lighter than life batteries’ 300ah?! Same cells and bms, strange?

 

Regarding configuring the bms I may sound a little nieve but I just want it configured for max life (so disconnect at 10% and stop charging at 90% soc for example) and just forget about it (apart from monitoring soc and top balancing if necessary).

[rusty69]

1 minute ago, n-baj said:

Thanks for the link rusty, just taken a quick look. Yes there is a weight difference alright! Fogstar 300ah is 8.5kg lighter than life batteries’ 300ah?! Same cells and bms, strange?

 

Regarding configuring the bms I may sound a little nieve but I just want it configured for max life (so disconnect at 10% and stop charging at 90% soc for example) and just forget about it (apart from monitoring soc and top balancing if necessary).

Yeah, I couldn't figure it out, I can only assume the cells used are different in some way. There is a video on youtube of a tear down of the fosgstar drop in ones.

 

I think the point with the BMS is to make sure that you get one that can be configured, ideally without invalidating the warranty. Not all of them you can, though I think Life and Fogstar use the ubiquitous overkill/JBD type BMS.

You shouldn't really need to top balance them if they have been done properly by the vendor.

[n-baj]

10 minutes ago, rusty69 said:

 

You shouldn't really need to top balance them if they have been done properly by the vendor.

Excellent, even less faff 👍 Thanks again 😃

[IanD]

The price looks good, but it's not clear from the data how (or if) these communicate with any charging system (e.g. alternator, inverter/charger, MPPT controllers) to stop charge at (say) 90% SoC and stop discharge at (say) 10% SoC, especially if there are multiple batteries in the system which need to be synchronised. If they do, great. If not, take care... 😉

[TheBiscuits]

1 hour ago, n-baj said:

I have no relationship with this company, just a potential lithium convert (I’ve seen Tony1’s set up last year)

 

If you buy less battery monitors than @Tony1 you'll be able to afford more batteries! 

 

[Tony1]

3 minutes ago, TheBiscuits said:

 

If you buy less battery monitors than @Tony1 you'll be able to afford more batteries! 

 

 

You forgot to mention my largely pointless array of B2B chargers!

But I remember showing the young chap my precious lithium batteries- the cheeky bugger fell asleep when I was only 3 hours into my lithium lecture...

I did warn him though, rule one is never take any notice of any advice I give!  🤣

 

 

[TheBiscuits]

4 minutes ago, Tony1 said:

You forgot to mention my largely pointless array of B2B chargers!

 

Point the vents towards your feet for winter cruising, they are lovely.  Not very efficient, but toasty warm!

[MtB]

2 hours ago, n-baj said:

Hello all, 

 

I'm planning to drag my DC system into the 21st century this summer and been researching lifepo4 for a while now. 
 

I was thinking of going for Sterling’s batteries but I’ve come across fogstar’s batteries currently on pre-order;

 

https://www.fogstar.co.uk/collections/lithium-leisure-battery/products/fogstar-drift-460ah-leisure-battery
 

I’m a little suspicious at the price (£1240 for 460ah and it’s heated) it seems too low to me? I believe cheap lifepo4 batteries use lower grade cells although they say they use grade A. I’m wondering what the lifepo4 experts think? 

also I know about the potential pitfalls of this battery chemistry (melting alternators, etc) and if this post looks like a shill post, it isn’t. I have no relationship with this company, just a potential lithium convert (I’ve seen Tony1’s set up last year)

 

many thanks,

 

R

 

Just an observation. i have the Renogy 200AH bluetooth battery and at 27.3kg it is a beast of a thing to move around. The 400AH batt you're considering is 38kg, about 50% heavier. Its also damned big and awkward, and only just fits the space I had in mind for it. Next time I want a 200AH of Li, I'll buy two x 100AH. 

 

Renogy are worth considering though. Mine works well but the BMS is very noddy, heavily dumbed down probably to reduce the number of idiots calling the technical helpline. Renogy gets heartily condemned by the Nordkyn design bod, yet got a rave review on a teardown video by Will Prowse. 

 

I also have a lifebatteries 100AH Li self-heating which has a very informative full fat BMS and weighs only 10.6kg, less than half the 200AH from Renogy! I've not measured capacity of either but my perception is the Renogy has more than twice the capacity of the Lifebatteries one. 

 

 

 

 

[PeterF]

1 hour ago, IanD said:

The price looks good, but it's not clear from the data how (or if) these communicate with any charging system (e.g. alternator, inverter/charger, MPPT controllers) to stop charge at (say) 90% SoC and stop discharge at (say) 10% SoC, especially if there are multiple batteries in the system which need to be synchronised. If they do, great. If not, take care... 😉

They do not communicate with the charging system, they are standalone and just isolate the battery from the system. The 12V group advocates these for the hybrid setup with a lead acid left in parallel so the alternator or other charger does not suddenly loose its power sink and give a voltage spike.

[nicknorman]

5 hours ago, n-baj said:

Hello all, 

 

I'm planning to drag my DC system into the 21st century this summer and been researching lifepo4 for a while now. 
 

I was thinking of going for Sterling’s batteries but I’ve come across fogstar’s batteries currently on pre-order;

 

https://www.fogstar.co.uk/collections/lithium-leisure-battery/products/fogstar-drift-460ah-leisure-battery
 

I’m a little suspicious at the price (£1240 for 460ah and it’s heated) it seems too low to me? I believe cheap lifepo4 batteries use lower grade cells although they say they use grade A. I’m wondering what the lifepo4 experts think? 

also I know about the potential pitfalls of this battery chemistry (melting alternators, etc) and if this post looks like a shill post, it isn’t. I have no relationship with this company, just a potential lithium convert (I’ve seen Tony1’s set up last year)

 

many thanks,

 

R

 

I don’t think it’s unreasonably cheap. I paid the same (in proportion) for my bare cells from china, so you are getting a BMS and case chucked in. Something like a heating element doesn’t add much to the build cost. It’s always a bit of a gamble but no red flags for me there. However the discharge is limited to less than 1/2C which is a bit restrictive, but might not matter if you don’t intend to run a big inverter load.

[Alan de Enfield]

3 hours ago, MtB said:

Just an observation. i have the Renogy 200AH bluetooth battery and at 27.3kg it is a beast of a thing to move around.

 

So there is 'benefit to Lithiums.

 

My 200Ah FLAs weigh 58 kgs each (I have 6 of them) and they are 'monstrous beasts' particularly when you have to try and lift them into the battery box whilst lying down, or at best, kneeling down.

[n-baj]

15 hours ago, IanD said:

The price looks good, but it's not clear from the data how (or if) these communicate with any charging system (e.g. alternator, inverter/charger, MPPT controllers) to stop charge at (say) 90% SoC and stop discharge at (say) 10% SoC, especially if there are multiple batteries in the system which need to be synchronised. If they do, great. If not, take care... 😉

 

14 hours ago, PeterF said:

They do not communicate with the charging system, they are standalone and just isolate the battery from the system. The 12V group advocates these for the hybrid setup with a lead acid left in parallel so the alternator or other charger does not suddenly loose its power sink and give a voltage spike.

thanks fellas, you’ve given me food for thought. I’m planning lead acid and alternator into a b2b charger which is the alternator looked after but the solar controller is after the b2b charger so will not be feeding the lead acid. The solar controller and b2b charger has a lifepo4 setting so figured it’s compatible but if the bms stops charging when the battery is full then will that damage the solar controller despite the lithium setting?

 

a third charging source is mains charger/inverter combi even though there’s no lithium setting I only use that with a generator in winter so charging at 14.4v setting and manually switch off when approaching full. On the very rare occasion I have access to shoreline I plan to discharge to around 50% soc and isolate the lithium from the system.

 

14 hours ago, MtB said:

 

Just an observation. i have the Renogy 200AH bluetooth battery and at 27.3kg it is a beast of a thing to move around. The 400AH batt you're considering is 38kg, about 50% heavier. Its also damned big and awkward, and only just fits the space I had in mind for it. Next time I want a 200AH of Li, I'll buy two x 100AH. 

 

Renogy are worth considering though. Mine works well but the BMS is very noddy, heavily dumbed down probably to reduce the number of idiots calling the technical helpline. Renogy gets heartily condemned by the Nordkyn design bod, yet got a rave review on a teardown video by Will Prowse. 

 

I also have a lifebatteries 100AH Li self-heating which has a very informative full fat BMS and weighs only 10.6kg, less than half the 200AH from Renogy! I've not measured capacity of either but my perception is the Renogy has more than twice the capacity of the Lifebatteries one. 

 

 

 

 

Thanks MtB however I’ve read from a couple of places that renology is not that good, having said that I’m planning to buy a renology b2b charger as several hundred for a sterling one is a mental price to me for a b2b charger. I’ve watched a couple of the Will Prose videos but felt like they’re adverts and he’s getting paid to give a good review (maybe I’m being unfair).

 

11 hours ago, nicknorman said:

I don’t think it’s unreasonably cheap. I paid the same (in proportion) for my bare cells from china, so you are getting a BMS and case chucked in. Something like a heating element doesn’t add much to the build cost. It’s always a bit of a gamble but no red flags for me there. However the discharge is limited to less than 1/2C which is a bit restrictive, but might not matter if you don’t intend to run a big inverter load.

Thanks nicknorman, I also feel the discharge limit is too low, I was contemplating getting 2x 240ah but that’s £400 more.

 

15 hours ago, Tony1 said: 

 

The only 2 appliances I have using more than 2kw is washing machine (2.1kw) and kettle (2.2kw). Washing machine I’ll use either with the engine running like I do currently or on a sunny day so with the solar making a 300w or so contribution it should be happy. Worse case is using the kettle in low light levels. Adding in inverter inefficiency it’s probably around a 200A draw. If battery says no then I’ll just get a lower power kettle.

[n-baj]

15 hours ago, Tony1 said:

 

You forgot to mention my largely pointless array of B2B chargers!

But I remember showing the young chap my precious lithium batteries- the cheeky bugger fell asleep when I was only 3 hours into my lithium lecture...

I did warn him though, rule one is never take any notice of any advice I give!  🤣

 

 

But I woke up again when you said you run your immersion heater off the batteries. Best I can do is run a kettle on sunny days as some sort of naff solar dump.

 

I was visiting a friend in normal society the other week and I was even managing to bore him with the differences between lead acid and lithium batteries and how they don’t sulphate, etc so I’ve turned into a lithium bore before I even got the damn batteries🤣

[rusty69]

10 minutes ago, n-baj said:

thanks fellas, you’ve given me food for thought. I’m planning lead acid and alternator into a b2b charger which is the alternator looked after but the solar controller is after the b2b charger so will not be feeding the lead acid. The solar controller and b2b charger has a lifepo4 setting so figured it’s compatible but if the bms stops charging when the battery is full then will that damage the solar controller despite the lithium setting?

It is possible. You will be effectively be cutting off the load from the MPPT. Although that is exactly what a fuse in the circuit will do if it blows, I'm not sure what long term problems it will cause if you are using the BMS as a charge control device.

 

For simplicity, I have connected all of my charge sources through the LA battery first, but the lower thresholds will obviously be detrimental to the LA battery long term, which requires a higher charging voltage.

 

Much better to set the solar parameters lower than the BMS cut off.

Edited February 14, 2023 by rusty69

[TheBiscuits]

2 minutes ago, n-baj said:

having said that I’m planning to buy a renology b2b charger as several hundred for a sterling one is a mental price to me for a b2b charger.

 

Just watch out that Renogy quote the output power of their B2B and Sterling quote the input power.

 

The Sterling 60A takes 60A from the charge source and delivers around 45A to the battery.  The Renogy 60A delivers 60A to the battery so takes 80-90A from the source.

 

It makes quite a difference if you're trying not to kill an alternator!

 

Both can be switched to half-power mode though, but if it's going to be used permanently, buy the smaller B2B!

 

I ended up going for a clearance Sterling - works fine but has a scratched case.

 

Also Renogy emailed me this morning to say they're having a sale this week.  It's of no interest to me, but if you have already decided on their product ...

[IanD]

4 minutes ago, n-baj said:

 

thanks fellas, you’ve given me food for thought. I’m planning lead acid and alternator into a b2b charger which is the alternator looked after but the solar controller is after the b2b charger so will not be feeding the lead acid. The solar controller and b2b charger has a lifepo4 setting so figured it’s compatible but if the bms stops charging when the battery is full then will that damage the solar controller despite the lithium setting?

 

a third charging source is mains charger/inverter combi even though there’s no lithium setting I only use that with a generator in winter so charging at 14.4v setting and manually switch off when approaching full. On the very rare occasion I have access to shoreline I plan to discharge to around 50% soc and isolate the lithium from the system.

 

Thanks MtB however I’ve read from a couple of places that renology is not that good, having said that I’m planning to buy a renology b2b charger as several hundred for a sterling one is a mental price to me for a b2b charger. I’ve watched a couple of the Will Prose videos but felt like they’re adverts and he’s getting paid to give a good review (maybe I’m being unfair).

 

Thanks nicknorman, I also feel the discharge limit is too low, I was contemplating getting 2x 240ah but that’s £400 more.

 

If you're wanting to be able to run more than one normal domestic electrical appliance at a time then 200A maximum current (limited by the JBD BMS) isn't really enough, and anyway I wouldn't want to push a BMS/battery like this to their absolute maximum limit because they're never clear about how long this can be sustained for.

 

If you want to do this then instead of 2 parallel 12V batteries you'd be better using either 2 in series or the 24V 280Ah battery (where 200A is 4.8kW nominal) and something like a Victron Multiplus II 24/5000 inverter/charger -- high power inverters are cheaper at 24V anyway. But then you've got to deal with how to get the alternator to charge them...

 

Alternatively, lower your expectations of how much power you need... 😉

[Tony1]

48 minutes ago, TheBiscuits said:

 

Just watch out that Renogy quote the output power of their B2B and Sterling quote the input power.

 

The Sterling 60A takes 60A from the charge source and delivers around 45A to the battery.  The Renogy 60A delivers 60A to the battery so takes 80-90A from the source.

 

It makes quite a difference if you're trying not to kill an alternator!

 

Both can be switched to half-power mode though, but if it's going to be used permanently, buy the smaller B2B!

 

I ended up going for a clearance Sterling - works fine but has a scratched case.

 

Also Renogy emailed me this morning to say they're having a sale this week.  It's of no interest to me, but if you have already decided on their product ...

 

This is a very important point. 

 

I bought two Sterling B2Bs, but my smaller alternator can't even deliver 45 amps without overheating to above 100 degrees- which I thought was a bit too hot, given the normal running temp is less than 60 degrees. 

Luckily the Sterling has a half power mode, so I switched down to that and the B2B delivers about 30 amps, which the alternator can do without getting hot. 

My alternators are pretty low capability, and yours may well be able to put out larger current and still stay cool, but I would strongly recommend doing some testing before you spend a few hundred on a B2B. 

 

You need to find out how much current the alternator can put out and still stay under 100 degrees or so. When testing, run it for at least 20 mins- and bear in mind that a test in cold weather with the engine cover off wont closely reflect summer use. 

 

You can test out your alternators capacity by buying a 10 metre length of cable that is about 10mm square, and connecting the long cable between the lead acid battery and the lithium battery (or between the alternator and the lead acid, I'm not sure if it matters that much).

I think the main thing is limit what goes into the lithiums, and keep an eye on the alternator temp every few mins. They can overheat really quickly, so be very very careful).

The length of the cable will control how much current can pass through, so you can shorten the cable length in say 50cm steps. In this way you can test increasing levels of current, and find out when the alternator gets too hot.  Its a lot of faffing fitting new lugs on the cable ends every time you chop half a metre off it, but its worth knowing your alternator's capacity.

 

With this approach you can find out what your alternators safe limit is, and buy a B2B that delivers the right current. 

Or you could just carry on charging using a long length of cable- loads of people are charging lithiums in parallel just using 'long wire' method. 

 

With the money saved form buying a B2B, you could more panels and another MPPT, and that way you might get enough solar for hot water during the summer, so that you dont need to run the engine half so much anyway. I think 1000 watts would pretty much guarantee solar hot water for a few months in the summer, and would extend the number of months that you get enough solar for a fridge and lights etc.

I have 1400 watts of panels, and yesterday I got just over 1700Wh of power from the panels, so no engine running was needed. Today not so good, but you get the point.

 

This will mean buying a clamp meter (to measure how much current is going through a cable) and an infra red type thermometer to keep an eye on the alternator, but tbh there will be other costs anyway. Lengths of cable, lugs, a decent crimper to fit the lugs, the list does go on a bit.

 

ETA- just a thought. Also test the alternator temp at different rpm, just out of interest. 

I found that if I charged at say 1300rpm, the alternator was able to put out more current before it started to overheat. 

Knowing that, I then bought a second B2B of lower power, and in winter when doing a static charge moored up, I switch on the extra B2B and up the revs to 1300rpm, and I can charge a bit faster with more current from the alternator. 

(That's not a suggested approach btw, I think I had gotten B2B fever at that point)

 

 

 

 

 

Edited February 14, 2023 by Tony1

[IanD]

3 minutes ago, Tony1 said:

 

This is a very important point. 

 

I bought two Sterling B2Bs, but my smaller alternator can't even deliver 45 amps without overheating to above 100 degrees- which I thought was a bit too hot, given the normal running temp is less than 60 degrees. 

Luckily the Sterling has a half power mode, so I switched down to that and the B2B delivers about 30 amps, which the alternator can do without getting hot. 

My alternators are pretty low capability, and yours may well be able to put out larger current and still stay cool, but I would strongly recommend doing some testing before you spend a few hundred on a B2B. 

 

You need to find out how much current the alternator can put out and still stay under 100 degrees or so. When testing, run it for at least 20 mins- and bear in mind that a test in cold weather with the engine cover off wont closely reflect summer use. 

 

You can test out your alternators capacity by buying a 10 metre length of cable that is about 10mm square, and connecting the long cable between the lead acid battery and the lithium battery.

The length of the cable will control how much current can pass through, so you can shorten the cable length in say 50cm steps. In this way you can test increasing levels of current, and find out when the alternator gets too hot.  Its a lot of faffing fitting new lugs on the cable ends every time you chop half a metre off it, but its worth knowing your alternator's capacity.

 

With this approach you can find out what your alternators safe limit is, and buy a B2B that delivers the right current. 

Or you could just carry on charging using a long length of cable- loads of people are charging lithiums in parallel just using 'long wire' method. 

 

With the money saved form buying a B2B, you could more panels and another MPPT, and that way you might get enough solar for hot water during the summer, so that you dont need to run the engine half so much anyway. I think 1000 watts would pretty much guarantee solar hot water for a few months in the summer, and would extend the number of months that you get enough solar for a fridge and lights etc.

I have 1400 watts of panels, and yesterday I got just over 1700Wh of power from the panels, so no engine running was needed. Today not so good, but you get the point.

 

 

More solar is almost *always* the best -- and nowadays, cheapest -- option, if you can fit it onto the roof. It's still less use in the middle of winter, but extends the part of the year where you don't need to run the engine/generator.

 

Here's mine (13 x 160W panels), but for obvious reasons it's not applicable to most boats... 😉

[rusty69]

10 minutes ago, Tony1 said:

This will mean buying a clamp meter (to measure how much current is going through a cable) and an infra red type thermometer to keep an eye on the alternator, but tbh there will be other costs anyway

Yeah but every boat should have an amp clamp and IR thermometer anyway. How else are we going to measure the temperature of everything that moves, and most things that don't for a whole week after buying one.

[TheBiscuits]

9 minutes ago, Tony1 said:

When testing, run it for at least 20 mins- and bear in mind that a test in cold weather with the engine cover off wont closely reflect summer use. 

 

Well no, I don't tend to use the B2B much in summer ...

 

 

 

3 minutes ago, IanD said:

Here's mine (13 x 160W panels), but for obvious reasons it's not applicable to most boats... 😉

 

Most non-electric boaters get a couple of panels and then say "Diesel do for me" 

[IanD]

2 minutes ago, TheBiscuits said:

 

Most non-electric boaters get a couple of panels and then say "Diesel do for me" 

 

Even if my boat wasn't electric (OK, hybrid...) I'd still fit as many panels on the roof as possible, and quite a few diesel boats seem to be taking the same approach... 😉

Edited February 14, 2023 by IanD

[TheBiscuits]

1 minute ago, IanD said:

 

Even if my boat wasn't electric (OK, hybrid...) I'd still fit as many panels on the roof as possible, and quite a few diesel boats seem to be taking the same approach... 😉

 

I quite agree, it just struck me as funny.

 

The real limit for solar on boats - as you are well aware - is available roof space for them.

 

Wallet depth is another consideration, but that can be spread out over time if needed, the roof size tends to stay fixed.

[Tony1]

9 minutes ago, TheBiscuits said:

 

Well no, I don't tend to use the B2B much in summer ...

 

 

No, the B2B is not used much in summer, but you do occasionally moor in a green tunnel with very little solar. 

With my original 660 watts of panels, I still had to use the B2Bs to charge the batteries in the summer of 2021 when I was moored just north of Chirk tunnel.

So I did have a quick check of the alternator temp as I was charging, and it was no problem.

But if you dont have much solar (not sure in the OPs case), then your B2B is going to be running most of the time when cruising. 

My alternator testing was done in late January, on a near-freezing day with the engine board off, and with a strong gusting wind.

So I did doublee check it a few times as things warmed up, and it was fine- but something to at least bear in mind, I would have thought.

 

 

Edited February 14, 2023 by Tony1