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Lifepo4 battery too cheap?


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On 20/02/2023 at 14:05, rusty69 said:

There are people on here with 4 year old lithium setups, but none that I know of have actually said they have killed them yet.

 

I am only a year into mine,so they need to last another few years to be as 'good' as the cheap LA batteries that I previously 

Ours have effectively now done 5 winters of full time off grid liveaboard use (installed September 2018), and we've not killed them yet! During that time we've double our electric usage, (and now have 2 kids to use the extra power!).

 

No regrets at all from us. Best investment we've made (other than the boat!), and more than paid for themselves. We're now running engine for around 1-1.5 hours a day in winter, down from what felt like all day running a genny with our old LA, and the LA were still knackered after a year. 

 

No constant monitoring or checking tail current to measure sure they get to 100% every few days, just charge when you like, and use what you like. Occasional glance at BMV to see how long to charge for around teatime is all the only monitoring we do. 

 

Batteries get a 100% charge to synchronise the BMV every month when we go for pumpout, but seems to remain accurate to within 5% during that time. 

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  • 2 weeks later...

After reading this topic many times and reaching for the headache pills. In conclusion would the Fogstar batteries be recommended? For my own purposes i would be looking at putting 4 x 560ah batteries in serial for connection to a 48v 8000 Multiplus ii.  I know the BMS in these batteries will not talk to the Victron and would need a smart shunt.

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11 minutes ago, MrFish said:

After reading this topic many times and reaching for the headache pills. In conclusion would the Fogstar batteries be recommended? For my own purposes i would be looking at putting 4 x 560ah batteries in serial for connection to a 48v 8000 Multiplus ii.  I know the BMS in these batteries will not talk to the Victron and would need a smart shunt.

I'm not sure anyone on here has them to be able to make a recommendation. 

 

Lots of satisfied customers of lifebatteries on Facebook though. 

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I suppose if a job is worth doing... 

 

Have you looked at the Pylontech batteries ? 

 

My school of thought is that whatever power one uses it needs to go back in so unless you have an extraordinarily large solar array or mains power input there will be a point at which the size of the battery bank will not be relevant in relation to what you can actually put into it on a daily basis. 

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52 minutes ago, MrFish said:

After reading this topic many times and reaching for the headache pills. In conclusion would the Fogstar batteries be recommended? For my own purposes i would be looking at putting 4 x 560ah batteries in serial for connection to a 48v 8000 Multiplus ii.  I know the BMS in these batteries will not talk to the Victron and would need a smart shunt.

Can they be connected in series with the built in BMS?

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5 minutes ago, ditchcrawler said:

Can they be connected in series with the built in BMS?

I contacted Fogstar and they confirmed that they can be connect up to 4 in series and 4 in parrallel

9 minutes ago, magnetman said:

I suppose if a job is worth doing... 

 

Have you looked at the Pylontech batteries ? 

 

My school of thought is that whatever power one uses it needs to go back in so unless you have an extraordinarily large solar array or mains power input there will be a point at which the size of the battery bank will not be relevant in relation to what you can actually put into it on a daily basis. 

I did look at Pylontech but unless i am mistaken they have a max 100A discharge. i do have a 5kw travel power and 2400w solar.

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2 minutes ago, MrFish said:

I contacted Fogstar and they confirmed that they can be connect up to 4 in series and 4 in parrallel

How much do 4 series batteries cost and what capacity do you get?

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2 minutes ago, MrFish said:

I contacted Fogstar and they confirmed that they can be connect up to 4 in series and 4 in parrallel

I did look at Pylontech but unless i am mistaken they have a max 100A discharge. i do have a 5kw travel power and 2400w solar.

What are you using which draws more than 100A from a 48v battery and isn't pushing the boat along? 

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7 minutes ago, magnetman said:

What are you using which draws more than 100A from a 48v battery and isn't pushing the boat along? 

I think my coffee machine uses 90A, so it wouldn't take much to find something quite normal that uses over 100A for a short time.

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8 minutes ago, magnetman said:

What are you using which draws more than 100A from a 48v battery and isn't pushing the boat along? 

Cooker, hob, kettle etc. Whilst in practice it will only be occasional times that all are on at once. I do also have some back up in terms of gas hob etc for charging may be a problem.

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1 minute ago, Richard10002 said:

I think my coffee machine uses 90A, so it wouldn't take much to find something quite normal that uses over 100A for a short time.

Is this on 48v?

1 minute ago, MrFish said:

Cooker, hob, kettle etc. Whilst in practice it will only be occasional times that all are on at once. I do also have some back up in terms of gas hob etc for charging may be a problem.

Ah yes the cooking. 

 

Gas is remarkably effective for this rather arduous task. 

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11 minutes ago, Richard10002 said:

I think my coffee machine uses 90A, so it wouldn't take much to find something quite normal that uses over 100A for a short time.

Your coffee machine takes 1.9kW?

 

Anyway, the answer to the question is "anything and everything connected to the mains output of a Multiplus II 48/8000" -- kettle, toaster, coffee machine, washing machine, hairdryer -- which can draw 140A from 48V. Which is too much for the Pylontechs (100A) but OK for the Fogstar (200A).

 

11 minutes ago, MrFish said:

£1699 per battery, so £6796. set up for 4 in series 48v 560ah.  or 26.8Kwh

 

With or without VAT?

Edited by IanD
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It seems a lot to spend just to avoid the Calor cartel. They may be terrible but having had LPG living on a number of different boats for 29 yars I can report that you won't be blown sky high by having this system. 

 

If you want to shift the job to the diesel via electric conversion then fair enough but the diesel engine makes a lot more noise than a gas bottle. 

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15 minutes ago, IanD said:

Your coffee machine takes 1.9kW?

 

Anyway, the answer to the question is "anything and everything connected to the mains output of a Multiplus II 48/8000" -- kettle, toaster, coffee machine, washing machine, hairdryer -- which can draw 140A from 48V. Which is too much for the Pylontechs (100A) but OK for the Fogstar (200A).

 

 

With or without VAT?

With

 

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18 minutes ago, magnetman said:

It seems a lot to spend just to avoid the Calor cartel. They may be terrible but having had LPG living on a number of different boats for 29 yars I can report that you won't be blown sky high by having this system. 

 

If you want to shift the job to the diesel via electric conversion then fair enough but the diesel engine makes a lot more noise than a gas bottle. 

Going "gas-free" or all-electric (including cooking) is expensive, and the problem of where to get the power from remains. Even with solar, you're likely to need another power source, especially in winter, and if you're not plugged in this means a generator (more cost, and possibly noise unless you spend a fortune) or hours of engine running. Having electric cooking *and* keeping gas as a back-up seems the worst of all worlds... 😞

 

People who've gone "gas-free" on diesel boats in the past have ended up having to run the generator when they wanted to cook. You won't have this problem, but you've still got to put back the increased energy you used up, which means you'll almost certainly either need a generator or to run the engine regularly even when moored.

 

I'm not saying all this can't be done, but it's a *very* expensive way of getting rid of gas cooking... 😉

Edited by IanD
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4 hours ago, MrFish said:

With

 

 

4 hours ago, IanD said:

Your coffee machine takes 1.9kW?

 

Anyway, the answer to the question is "anything and everything connected to the mains output of a Multiplus II 48/8000" -- kettle, toaster, coffee machine, washing machine, hairdryer -- which can draw 140A from 48V. Which is too much for the Pylontechs (100A) but OK for the Fogstar (200A).

 

 

With or without VAT?

If one had 4 of the said batteries in series would it be reasonable to suspect that the maximum current rating may be ruled by one of the BMS circuits?

If this were the case it would be 200A at nominal 13.2v rather than 200A at nominal 52.8v. Big difference in the killer watts.

 

Worth checking I think. Series layout with batteries with individual BMS could be awkward. 

 

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15 minutes ago, magnetman said:

 

If one had 4 of the said batteries in series would it be reasonable to suspect that the maximum current rating may be ruled by one of the BMS circuits?

If this were the case it would be 200A at nominal 13.2v rather than 200A at nominal 52.8v. Big difference in the killer watts.

 

Worth checking I think. Series layout with batteries with individual BMS could be awkward. 

 

 

I looked at the fogstar website, they do seem adamant that one can have up to 4 in series. Not totally sure how that works BMS-wise but I also note they have Bluetooth so maybe the BMSs talk to each other via Bluetooth?

 

Although I suppose that if any one BMS detects too high or too low cell voltage for its own cells, it shuts off its FETs and that interrupts the current for the entire string of batteries, so maybe I am overthinking it.

 

Edited by nicknorman
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21 minutes ago, nicknorman said:

 

Although I suppose that if any one BMS detects too high or too low cell voltage for its own cells, it shuts off its FETs and that interrupts the current for the entire string of batteries, so maybe I am overthinking it.

 

That was my thought when I posted about series connection 

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17 hours ago, IanD said:

Going "gas-free" or all-electric (including cooking) is expensive, and the problem of where to get the power from remains. Even with solar, you're likely to need another power source, especially in winter, and if you're not plugged in this means a generator (more cost, and possibly noise unless you spend a fortune) or hours of engine running

 

 

With 2.4kw of solar I would guess the OP's electricity needs will be more than met for most of the year, and I'm sure he's already well aware of the seasonal issue, but it may be worth repeating for any newbies thinking about going electric for cooking.  

My own experience over the last 18 months with a 1.4kw solar setup has been that you have enough energy for hot water on most days between April and mid-Sept, so with 2.4kw of panels his solar hot water 'season' might well extend into October, and all the electrical equipment will be fine, although there may come a time in late Sept when the solar energy is reducing, and you have to choose between using the solar for hot water, or using it to power a cooker/washing machine etc.

As we know, with all the solar setups, there is that period between say mid-Nov to mid-Feb, where the input is pretty paltry on most days. In Dec and Jan, on most days my panels yield barely enough power to keep a fridge running- let alone to replace any of the power used used over the last 24 hours- so there will be a lot of power generation needed on maybe 90-100 days of the year. 

But I do understand feeling a desire to remove gas from the picture- it feels like one less critical dependency, and that has an appeal at a time when gas supplies seem to be constantly at risk (e.g. a fuel boat text yesterday to say they will have a limited gas bottles on their next run). 

I'm sure there's a fair bit scaremongering about gas supplies, and there certainly was in late 2020, but it does seem to create a slight but nagging doubt.

I've considered getting an induction hob myself, as a way to utilise the excess solar in the warmer months, and to further reduce the usage of gas.   

But in my case the gas is definitely staying put, because for those 100 days of the year when the solar is very low, having electric cooking just means more genny running/engine running, and I dont know how the cost figures stack up when comparing gas cooking to electric cooking (using electricity created from burning diesel fuel and a genny of some sort). 

 

 

Edited by Tony1
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3 minutes ago, Tony1 said:

 

With 2.4kw of solar I would guess the OP's electricity needs will be more than met for most of the year, and I'm sure he's already well aware of the seasonal issue, but it may be worth repeating for any newbies thinking about going electric for cooking.  

My own experience over the last 18 months with a 1.4kw solar setup has been that you have enough energy for hot water on most days between April and mid-Sept, so with 2.4kw of panels his solar hot water 'season' might well extend into October, and all the electrical equipment will be fine, although there may come a time in late Sept when the solar energy is reducing, and you have to choose between using the solar for hot water, or using it to power a cooker/washing machine etc.

As we know, with all the solar setups, there is that period between say mid-Nov to mid-Feb, where the input is pretty paltry on most days. In Dec and Jan, on most days my panels yield barely enough power to keep a fridge running- let alone to replace any of the power used used over the last 24 hours- so there will be a lot of power generation needed on maybe 90-100 days of the year. 

But I do understand feeling a desire to remove gas from the picture- it feels like one less critical dependency, and that has an appeal at a time when gas supplies seem to be constantly at risk (e.g. a fuel boat text yesterday to say they will have a limited gas bottles on their next run). 

I'm sure there's a fair bit scaremongering about gas supplies, and there certainly was in late 2020, but it does seem to create a slight but nagging doubt.

I've considered getting an induction hob myself, as a way to utilise the excess solar in the warmer months, and to further reduce the usage of gas.   

But in my case the gas is definitely staying put, because for those 100 days of the year when the solar is very low, having electric cooking just means more genny running/engine running, and I dont know how the cost figures stack up when comparing gas cooking to electric cooking using diesel fuel and power from a genny of some sort. 

 

 

All true -- but bear in mind that if the OP uses electricity for cooking (and kettle, and toaster, and microwave, and PC, and...) his usage is likely to be significantly greater than yours.

 

A power audit is absolutely essential to make all these decisions, becasue different people have different power requirements so it's difficult to say "it works for me, so it will work for you"... 🙂

 

Propane contains 50MJ/kg, diesel energy is 37MJ/l. Using the diesel to power a generator and then an induction hob via an inverter is about 20% efficient, meaning 7.5MJ of energy ends up in the pan from each litre of diesel; if diesel cost is £1.20/l  this means the cost is 16p/MJ. Burning propane on a ring about 40% of the energy ends up in the pan, so 20MJ from 1kg of gas. If a 13kg Calor bottle costs £36, this is £2.77/kg, meaning 14p/MJ -- pretty much the same as a diesel generator.

 

However if you charge your batteries by running the diesel propulsion engine the cost will be something like 2.5x higher than using a generator because the efficiency (engine+alternator) is much lower, this puts the cooking cost up to 40p/MJ which is *much* higher than gas. But if you have spare solar power instead of burning diesel, this will bring the cost down again somewhat.

 

Which means that if you have solar and a generator (like an electric boat...) cooking with electric is cheaper than gas, if you have solar and a diesel engine for charging (like you) it's more expensive, with just a diesel and no solar it's a *lot* more expensive.

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