Lithium Batteries

[DuncanHall]

After going through a set of AGM batteries in just over 2 1/2 years, I believe the time has come to change over to lithium. My existing system has about 480AH of capacity but I
found this is down to a small fraction of that now following my system giving low voltage alarms after discharging about 50AH.

I have a system with a Victron multiplus inverter charger ( C/12/1600/70). This regulary is used to power mains systems drawing typically 100A and ocasionally more. This summer was typical in that for weeks at a time the battery bank sat at 80% SOC or less. I have about 200W of solar on a partially shaded deck but that is insufficient to recharge the batteries each day when we are aboard. Accordingly I am tempted to switch to lithium as they are claimed to better survive in those situations.

I have looked at the options and have come down to two options


1 Go for quality and buy a single 200AH Victron lithium FE04 with a Smart BMS 12/200 to manage the alternator. This with the neceserry cables costs about £2100. It has the advantag of a single DC31 size battery giving room to expand the bank if needed.
2 Go for a cheaper e.g. Renology probably requiring 3 100 AH units to give the maximum current required for the inverter (150A) with a 60A DC to DC charger costing about £1550. Advantage greater capacity but quality?

There seems a large host of low cost lithium about but not much info about its reliability and the value of any guarentee given most of the companies are relativly new.

Has anyone any views as to the best or other options?

 

[RunAgroundHard]

I can't help, but I have been reading about Lithium Battery systems on Attainable Adventure Cruising. This is a subscription service, so you would have to pay. They have been researching and advising on Lithium Battery systems and have, what I believe, good system design notes. I think it would be worth a years subscription to access information that is impartial and designed to cut through the bull. All the best with your system. I have no association with ACC except as a subscriber.

 

[Trident]

I have fitted around 50 or 60 Renogy batteries in the last year on everything from 25 feet boats to a an enormous cat with with a recording studio in one hull to power. They have been tested on my own boat for 3 years now (totally off grid) and dealt with an all electric galley and providing 240v power year round

Renogy do several batteries with the same architecture (that is pouch cells and a built in BMS) but I can say from more experience than most they are all good but ideally choose the 100A non bluetooth smart battery. All the BT versions (100 and 200a) will last as long and charge the same etc but their BT app is utter cr*p and you'll be much better off with a wired monitor from Renogy for an extra £30 and they can be monitored as a bank that way too

As an aside I would choose Renogy over Victron regardless of cost - the Victron batteries are not even close to the best on the market (In testing and in my experience Battleborn are the best - at about £1K each and no UK distributor as yet and Renogy a close second) Renogy however are a bit useless sometimes on customer service but if its in stock in the UK they'll deliver in a couple of days (I'm a Renogy dealer now by the way so feel free to PM for prices and info etc - I'm also a Victron authorised dealer too just so it doesn't look like I have a reason to uptalk Renogy)

3 Renogy 100s with a 60 amp DCDC as you suggest (assuming a large enough alternator to cope) would accept charge faster and make better use of the solar you have as they don't waste time with the absorb stage for lithium... BUT

Does your solar controller have a Lithium or customisable setting? If not budget for a Renogy MPPT controller to charge the LifePo4

Do you have the version of Multiplus with BT to control the settings ? If not you'll need to buy a VE Bus Dongle or for Mac a USB3 to connect to the Victron to change the charge settings on that to Lithium suitable - you'll also need a password (PM me) to access those settings

The thing to remember is that whatever anyone says (Renogy and Victron included) these are not drop in that just charge like lead acid - you'll want to charge at14.4v, set absorb times to zero or minimum (30 minutes IIRC on the Multiplus) and set float to off or 13.2V if no off setting - anything else will limit the life of the batteries. Also make sure they can't get down to zero degrees if you have the charging sources active over winter

 

[dunedin]

After going through a set of AGM batteries in just over 2 1/2 years, I believe the time has come to change over to lithium.

Do you first need to find out what the faults are in your boat systems that caused the AGM batteries to die so quickly?

Our AGM house batteries get heavily used but are now 10 years old.

 

[Pete7]

As an aside I would choose Renogy over Victron regardless of cost - the Victron batteries are not even close to the best on the market (In testing and in my experience Battleborn are the best - at about £1K each and no UK distributor as yet and Renogy a close second) Renogy however are a bit useless sometimes on customer service but if its in stock in the UK they'll deliver in a couple of days

I am surprised you feel Victron are not even close to the best on the market, given they use Winston cells. Renogy puts me off with their dire customer support. Trustpilot makes some worrying reading: Renogy is rated "Poor" with 2.5 / 5 on Trustpilot

Pete

 

[DuncanHall]

I have fitted around 50 or 60 Renogy batteries in the last year on everything from 25 feet boats to a an enormous cat with with a recording studio in one hull to power. They have been tested on my own boat for 3 years now (totally off grid) and dealt with an all electric galley and providing 240v power year round

Renogy do several batteries with the same architecture (that is pouch cells and a built in BMS) but I can say from more experience than most they are all good but ideally choose the 100A non bluetooth smart battery. All the BT versions (100 and 200a) will last as long and charge the same etc but their BT app is utter cr*p and you'll be much better off with a wired monitor from Renogy for an extra £30 and they can be monitored as a bank that way too

As an aside I would choose Renogy over Victron regardless of cost - the Victron batteries are not even close to the best on the market (In testing and in my experience Battleborn are the best - at about £1K each and no UK distributor as yet and Renogy a close second) Renogy however are a bit useless sometimes on customer service but if its in stock in the UK they'll deliver in a couple of days (I'm a Renogy dealer now by the way so feel free to PM for prices and info etc - I'm also a Victron authorised dealer too just so it doesn't look like I have a reason to uptalk Renogy)

3 Renogy 100s with a 60 amp DCDC as you suggest (assuming a large enough alternator to cope) would accept charge faster and make better use of the solar you have as they don't waste time with the absorb stage for lithium... BUT

Does your solar controller have a Lithium or customisable setting? If not budget for a Renogy MPPT controller to charge the LifePo4

Do you have the version of Multiplus with BT to control the settings ? If not you'll need to buy a VE Bus Dongle or for Mac a USB3 to connect to the Victron to change the charge settings on that to Lithium suitable - you'll also need a password (PM me) to access those settings

The thing to remember is that whatever anyone says (Renogy and Victron included) these are not drop in that just charge like lead acid - you'll want to charge at14.4v, set absorb times to zero or minimum (30 minutes IIRC on the Multiplus) and set float to off or 13.2V if no off setting - anything else will limit the life of the batteries. Also make sure they can't get down to zero degrees if you have the charging sources active over winter

My victron system is interfaced to a Raspbery Pi running venus and connected with a BMV the multiplus and a Victron MPPT 75/15. So setting charge voltages is not difficult infact I can do it from home!

 

[Pete7]

You might take a look at Life Batteries. Mark the owner is very active on the 12v boat Facebook group and stands by his products which nice to see. Alternatively Sterling who offer a 5 year warranty which is why I chose them.

LiFePO4 battery supplies | LiFe Batteries

 

[Tranona]

Good illustration of the (im)practicality of running 240v appliances off a 12v system. As you say solar will never keep pace with your consumption and you AGMs will never get fully charged, plus as you report will regularly get heavily discharged. Not surprising they only last a short time with this kind of abuse for which they were never designed.

Lithium will obviously be better because they will tolerate deep discharge and accept rapid recharge so even if your solar cannot keep up, short periods of running the engine will bring them up. Whether 200ah is enough depends partly on how long a period you want to go without a supplementary top up (engine or shorepower). You don't say what your actual daily usage is, your daily yield from your solar nor how many days you spend on board - all these are key bits of data needed for designing your system.

 

[DuncanHall]

Good illustration of the (im)practicality of running 240v appliances off a 12v system. As you say solar will never keep pace with your consumption and you AGMs will never get fully charged, plus as you report will regularly get heavily discharged. Not surprising they only last a short time with this kind of abuse for which they were never designed.

Lithium will obviously be better because they will tolerate deep discharge and accept rapid recharge so even if your solar cannot keep up, short periods of running the engine will bring them up. Whether 200ah is enough depends partly on how long a period you want to go without a supplementary top up (engine or shorepower). You don't say what your actual daily usage is, your daily yield from your solar nor how many days you spend on board - all these are key bits of data needed for designing your system.

This may help its a log of consumed AH over the summer. Thats what makes me think 200AH may be enough but 300 better. I would add I have a honda generator which is ocasionally used to top the batteries up.

 

[PaulRainbow]

Doesn't matter what batteries you fit, or how many Ah, if your consumption is greater than your power generations (shore, solar, engine) you will kill the batteries in short order.

 

[Tranona]

This may help its a log of consumed AH over the summer. Thats what makes me think 200AH may be enough but 300 better. I would add I have a honda generator which is ocasionally used to top the batteries up.

View attachment 146492

That is useful - assume that is net of any charge input? What is the state of charge of the batteries at the start of each cycle? What is the difference between the SOC when you leave the boat and the next visit - in other words does the solar bring them back up to full charge? How much motoring do you do each visit? Do you ever use shorepower? All relevant to how deep you dig into your battery capacity.

 

[DuncanHall]

That is useful - assume that is net of any charge input? What is the state of charge of the batteries at the start of each cycle? What is the difference between the SOC when you leave the boat and the next visit - in other words does the solar bring them back up to full charge? How much motoring do you do each visit? Do you ever use shorepower? All relevant to how deep you dig into your battery capacity.

Yes its net of charge inputs. Batteries are usually fully charged as I plug into mains at my home marina. Consequently they are fully charged once the boat has had 24 hrs in dock. The solar can bring them up to charge. In 2021 I was stranded on the river turo for 40 days and when I left the boat it recharged the system in 3 days. It put in about 0.5kWh per day. I suspect it over states the benefit of charging due to the efficiency of charging being low arround the 80% charge level.

 

[Graham376]

Doesn't matter what batteries you fit, or how many Ah, if your consumption is greater than your power generations (shore, solar, engine) you will kill the batteries in short order.

I agree. My first set of Trojans only lasted about 4 years, 200w of solar even in Algarve sun wasn't enough and that's without any large 240v loads. Uprated solar to 320w a couple of years ago and domestic bank usually on float now by around mid-day.

 

[Trident]

Doesn't matter what batteries you fit, or how many Ah, if your consumption is greater than your power generations (shore, solar, engine) you will kill the batteries in short order.

True but as you know an AGM or FLA will waste a lot of the possible solar input by having a 4 or even 8 hour absorb cycle in the charge where only a fraction of the available solar will be used to top the last few % of charge to full - the LifePo4 needs no absorb charge really so the same solar panels can put their full capacity in right up to full which makes a big difference

 

[Trident]

I am surprised you feel Victron are not even close to the best on the market, given they use Winston cells. Renogy puts me off with their dire customer support. Trustpilot makes some worrying reading: Renogy is rated "Poor" with 2.5 / 5 on Trustpilot

Pete

As I said in my post Renogy customer service is not great - though they have a dedicated dealer desk who are very helpful - but the batteries are very well made and I've had zero products with faults
Victron only get 3/5 on Trustpilot though to be fair there are only 11 reviews!

 

[KompetentKrew]

Do you have the version of Multiplus with BT to control the settings ? If not you'll need to buy a VE Bus Dongle or for Mac a USB3 to connect to the Victron to change the charge settings on that to Lithium suitable - you'll also need a password (PM me) to access those settings

I have a Mutiplus and the bluetooth dongle - are the advanced settings available with this please., @Trident

With the app and the bluetooth dongle I can set inverter/charger/both mode, and restrict draw on the AC input ("PowerControl" / "PowerAssist", which doesn't seem to work very well) but I can't find settings for the charging voltages, Dynamic current limiter, WeakAC or Search mode.

It looks like the advanced settings are only available using the USB programming cable, but maybe I'm missing something?

 

[geem]

True but as you know an AGM or FLA will waste a lot of the possible solar input by having a 4 or even 8 hour absorb cycle in the charge where only a fraction of the available solar will be used to top the last few % of charge to full - the LifePo4 needs no absorb charge really so the same solar panels can put their full capacity in right up to full which makes a big difference

I use a Victron Mppt with 720w of solar. We never see an 8 hour absorption period. We find that typically the bulk and absorption period combined is about 6 to 7 hours. Absorption is usually about 2 hours out of this period.
My understanding is that lithium is typically 20% better at accepting charge than lead

 

[Trident]

I have a Mutiplus and the bluetooth dongle - are the advanced settings available with this please., @Trident

With the app and the bluetooth dongle I can set inverter/charger/both mode, and restrict draw on the AC input ("PowerControl" / "PowerAssist", which doesn't seem to work very well) but I can't find settings for the charging voltages, Dynamic current limiter, WeakAC or Search mode.

It looks like the advanced settings are only available using the USB programming cable, but maybe I'm missing something?

With a windows PC or a Mac (if you have the USB3 interface) you can change the charge current to any setting and also the float and absorb times and voltages etc

 

[Trident]

I use a Victron Mppt with 720w of solar. We never see an 8 hour absorption period. We find that typically the bulk and absorption period combined is about 6 to 7 hours. Absorption is usually about 2 hours out of this period.
My understanding is that lithium is typically 20% better at accepting charge than lead

Hi Tim, each charger has its own algorithm but I think 4 hours is the normal for absorb but 2 is certainly not abnormal - but with LifePo4 you don't need an absorb mode so instead of a reducing output at steady state voltage you can have two hours of the full output of the panel - also if a big draw takes too much out of the batteries mid absorb cycle it will start again (after any bulk change that may be needed) and so you can end up wasting a lot of possible solar power . Its no big deal if you never need it but for the OP his small 200W solar array would put a lot more power in to the batteries without the absorb cycle

 

[kwb78]

My understanding is that lithium is typically 20% better at accepting charge than lead

LiFePo4 batteries are much better than that at accepting charge. They have minimal internal resistance so will take whatever your charger can give them in bulk charging (BMS allowing), and they don't really require an absorption phase unlike a lead acid battery, so charging is much more efficient. Most manufacturers recommend charging at 0.5C or thereabouts for best life, so for a 100Ah battery normal bulk charging should be 50A, and it will be full in 2 hours. A 100Ah lead acid battery will not normally pull anywhere close to that unless very discharged, and they will not be fully charged until the absorption phase is complete which can take a couple of hours.