LiFePo4 - Add on Battery - BOS LE 300

[Pete7]

Originally Posted by wholybee

Among the best advantages of LFP are that there is almost zero Peukert factor. There is no need for temperature compensation. You can use (almost) 100% of the capacity. There is no risk of damage due to PSOC.

Agreed.

Originally Posted by wholybee

As soon as you create a hybrid bank, you lose those advantages. You have more capacity, but you have a battery that is difficult to know the SOC, that you need to monitor, calibrate and perform maintenance on. You have added capacity, but lost almost all of the advantages of LFP.

You don't loose those advantages. Running heavy loads is exactly the same as is charging. This is because the lead-acid (LA) doesn't do much until the LFP is nearly flat. Even during heavy loads we see very little power coming from the LA. The SOC can be estimated by voltage as we all used to do, but actually its normally full. Not aware of any requirement to calibrate a lead acid battery but yes a couple of times a year I have to check the fluid levels and add a several tea spoons of water to my FLA, hardly a difficult task.

Originally Posted by wholybee

I think many don't realize how life changing those advantages are. LFP if done right is a forget about it thing. Like being on shore power. You don't have to worry if it is fully charged regularly. You don't have to check that your SOC meter is correct, or recalibrate for capacity loss every year. Just set an alarm at 10% SOC so you can recharge before the lights go out. And if the lights do go out, you don't damage anything, you just have no power until you recharge.

Oh we are quite aware of how life changing this is. Particularly for smaller yachts which don't want to or can't carry huge LA banks. The "lights out" situation is one that does worry me. Arriving at a strange harbour at night with no lights or chart plotter and VHF is a concern and something I want to avoid. The LA provides the extra re-assurance that in the event of running out, I still have some capacity to run systems. Yes the lights might go dim and the chart plotter complain of low voltage, but it still works giving breathing space to do something about it.

Originally Posted by wholybee

The trend is that people want more tech, so they add all this complexity to LFP so they can micromanage it. But that is the opposite of what LFP needs. And they are so used to micromanaging AGMs, they are totally lost on how easy LFP is because they never give it a chance.

What is this extra complexity? It's a pos and neg wire from the LA to the LFP. I am not sure AGMs are great for house banks. I prefer FLA which don't require micromanaging.

Originally Posted by wholybee

I get the desire to not throw away good AGM. But AGM is so heavy and huge compared to LFP. It only really makes sense if you have say a 2 year plan to buy half an LFP bank now, and the other half next year for budgetary reasons. And even then I would strongly discourage it.

Again, no need for AGM in a hybrid bank. We need to get away from the idea that AGM is wonderful tech. In a hybrid bank many of the advantages of AGM aren't needed. Indeed save the $$$ and either use FLA or SLA.

Originally Posted by wholybee

When not onboard or away, just set the full charge voltage of the solar to 3.8V or less. Then it is just as good as an AGM in that situation.

3.8v per cell is way too high for either LFP or AGMs. Therefore no I will not be following that piece of advice and should others tread with caution before making any changes.

You seen very anti hybrid. What was your experience of running a hybrid bank? You have tried it haven't you? Perhaps the reader would prefer the advice from those who have been running hybrid for some time. Three years in our case.

Clearly we have different view points, but then it would be very boring if there was only a "Hobsons Choice".

[HeinSdL]

I probably would not design a hybrid system from the ground up but I have my old lead acid batteries so I keep them, for now. The optionality presented by them I find interesting (an option might have value 0 but that's the minimum, it cannot have negative value).

Then the question remains, what to do with them.

When not on board, the lfp is disconnected at around 50% SOC and the solar panels keep the lead acid batteries topped up while powering the bilge pump. This is a happy situation for me.

When on board there is more optionality. To start with by just only using the lfp. This is proving handy for me while I get to know how the lfp works in conjunction with solar/shore/dcdc chargers and a smart shunt, all Victron except the battery which is a 300Ah Litime. I find the improvement so far spectacular, as mentioned up thread.

And then the lead acid is there should something happen to the lfp. Just switch. I am still getting familiar with lfp so I like the fall back option, for now.

Or, I could just add the lead acid into the system, down stream of the smart shunt. Then SOC calc of the lfp will not be effected though I might not know precisely what's going on with the lead acids. But since they're mainly seeing 13.2V+, presumably they sit there in good shape.

I should also say that originally I had space for 4x 120Ah batteries, now 2 spaces are still lead acid, under a bunk somewhere, while the other 2 spaces now hold the single lfp, in the main saloon. I would not have created more space for the lead acid batteries, but since I was already set up with space and cabling, my reasoning was, why not?

So, like I said I would not advocate for such a setup from scratch, but I really don't see any downside.

[Tortuga's Lie]

Originally Posted by wholybee

The actual LFP battery/cells can withstand huge currents, much more than lead-acid. The limitation is that the BMS in most drop-in batteries can't. So, typically, a lead-acid is retained for starting, but not as a hybrid, as the 2 banks would be kept isolated from each other. And starting is really the perfect application for lead-acid, as starting uses almost no capacity(Ah) so quickly gets back to 100% and stays there. Lead-Acid sucks for a deep cycle house bank, so that bank should be 100% LFP.

As an alternative there are a few drop-in LFP batteries that are built for starting and have a BMS that can take it. Expensive, but a few people spring for them. Or, if you opt to not use a drop-in but build a bank from scratch, then it's relatively easy to build one that can be used for starting.

The MC-618 will protect your alternator from overheating, yes. Make sure that the alternator temperature probe is installed, and make sure it is set for a Lithium profile. It would also be a good idea to add the Balmar APD to protect from an unexpected BMS disconnect.

Thanks Warren, very helpful and sounds like some good guidance. My AGM battery bank is still very healthy as it's only a couple of years old and since the LFP technologies aboard boats is relatively young, perhaps when I am ready for an upgrade, LFP's will have worked out all of the issues??? Or maybe there will be some positive developments with sodium-ion batteries, which will be interesting. https://pubs.acs.org/doi/10.1021/acsenergylett.0c02181
Cheers

[wholybee]

Originally Posted by Tortuga's Lie

Thanks Warren, very helpful and sounds like some good guidance. My AGM battery bank is still very healthy as it's only a couple of years old and since the LFP technologies aboard boats is relatively young, perhaps when I am ready for an upgrade, LFP's will have worked out all of the issues??? Or maybe there will be some positive developments with sodium-ion batteries, which will be interesting. https://pubs.acs.org/doi/10.1021/acsenergylett.0c02181
Cheers

I think the exotic chemistries like sodium are still a ways off. LFP is now a mature technology and the issues *are* worked out. They have been installed in boats for 15 years now in some cases. Prices have come down and there are hundreds of products to choose from at whatever your budget. Mostly the issue is that people are stubborn and refuse to learn about them and/or are scared of them.

[CaptainRivet]

Originally Posted by Pete7

Agreed.



You don't loose those advantages. Running heavy loads is exactly the same as is charging. This is because the lead-acid (LA) doesn't do much until the LFP is nearly flat. Even during heavy loads we see very little power coming from the LA. The SOC can be estimated by voltage as we all used to do, but actually its normally full. Not aware of any requirement to calibrate a lead acid battery but yes a couple of times a year I have to check the fluid levels and add a several tea spoons of water to my FLA, hardly a difficult task.



Oh we are quite aware of how life changing this is. Particularly for smaller yachts which don't want to or can't carry huge LA banks. The "lights out" situation is one that does worry me. Arriving at a strange harbour at night with no lights or chart plotter and VHF is a concern and something I want to avoid. The LA provides the extra re-assurance that in the event of running out, I still have some capacity to run systems. Yes the lights might go dim and the chart plotter complain of low voltage, but it still works giving breathing space to do something about it.



What is this extra complexity? It's a pos and neg wire from the LA to the LFP. I am not sure AGMs are great for house banks. I prefer FLA which don't require micromanaging.



Again, no need for AGM in a hybrid bank. We need to get away from the idea that AGM is wonderful tech. In a hybrid bank many of the advantages of AGM aren't needed. Indeed save the $$$ and either use FLA or SLA.



3.8v per cell is way too high for either LFP or AGMs. Therefore no I will not be following that piece of advice and should others tread with caution before making any changes.

You seen very anti hybrid. What was your experience of running a hybrid bank? You have tried it haven't you? Perhaps the reader would prefer the advice from those who have been running hybrid for some time. Three years in our case.

Clearly we have different view points, but then it would be very boring if there was only a "Hobsons Choice".

fully agree all on that...i am forced to run hybrid on the BB engine as i cannot get LFP or LTO deliveried here to canaries but cannot wait to get rid of them as soon as i am in a location i can get LTOs shipped too the order goes out. all is already prepared for that...
manage to get rid of STB lead starter and start from LFP house...its a joy not to think about these b.. lead starters anymore, floating, fill up water...


and for the ones they float with DC2DC charger well i done that due to factory spec of battery and the 2 sealed FLA 3 month old overcharged or had an internal cell short and boiled to death...since doing it via an Ip43 Phönix 1/1/50 (in 110V) with proper 5 stage charging and storage mode no issues anymore but was a 550Euro invest to get these lead properly charged and floated so they are worth the weight to stay onbaord. the phönix runs via inverter which is always on anyhow due to freezer and starlink, due to BMV712 more effective then the b.. DC2DC 30A from victron which have a lot losses due to heat. That phönix is then shorepower charge for Lithium house on a 230V boat in 110V countries for the future..now taking properly care of leads with a 110 to 230V adapter i already had.

[wholybee]

Clearly we have different view points, but then it would be very boring if there was only a "Hobsons Choice".

Boring it would be. If we ever meet on the water I will happily enjoy a beer with you and I expect the hybrid topic won't even come up. I am pretty sure your boat will be working just fine.

[HeinSdL]

Originally Posted by wholybee

Boring it would be. If we ever meet on the water I will happily enjoy a beer with you and I expect the hybrid topic won't even come up. I am pretty sure your boat will be working just fine.

Amen to that! Sitting on my X here in Genoa where it has been pretty rough (wind) the last days now calm but pouring down, I do miss the proper human contact from time to time: most of the issues here on CF are only issues because we cannot readily talk about them over a beer!

[CaptainRivet]

Originally Posted by HeinSdL

Amen to that! Sitting on my X here in Genoa where it has been pretty rough (wind) the last days now calm but pouring down, I do miss the proper human contact from time to time: most of the issues here on CF are only issues because we cannot readily talk about them over a beer!

agree but its also you, grab the dingy drive over to your neigbours and invite them for a sunddowner beer or longdrink...if that doesn't fit them today it will on the next 2 or 3 days. or if i go ashore i dirve to my neigbour and ask him to have a look at my vessel...as thank you i invite them for sundowner...hardly anyone said no...

[HeinSdL]

Originally Posted by CaptainRivet

agree but its also you, grab the dingy drive over to your neigbours and invite them for a sunddowner beer or longdrink...if that doesn't fit them today it will on the next 2 or 3 days. or if i go ashore i dirve to my neigbour and ask him to have a look at my vessel...as thank you i invite them for sundowner...hardly anyone said no...

And I agree too. But here it's winter in a very miserable Genoa and I am kind of in the middle of an industrial terrain, alone! Under normal circumstances I do meet plenty of fellow enthusiasts in the various marinas where conversations are usually more about destinations and life! Not so much about an LFP/FLA hybrid set up! :-)

[CaptainRivet]

Originally Posted by Tortuga's Lie

Thanks Warren, very helpful and sounds like some good guidance. My AGM battery bank is still very healthy as it's only a couple of years old and since the LFP technologies aboard boats is relatively young, perhaps when I am ready for an upgrade, LFP's will have worked out all of the issues??? Or maybe there will be some positive developments with sodium-ion batteries, which will be interesting. https://pubs.acs.org/doi/10.1021/acsenergylett.0c02181
Cheers

a very easy fix to that is buy the winston 40-90AH LFP batteries without a BMS and use them as starter,
https://shop.gwl.eu/en/By-Brand-Manu...f2cjjkmvbmo2ep


you can simply parallel them with an argofet to your house bank to main busbar but just connect the starter to it. the argofet so you get the charge in parallel but the starter is only connected to winston so it cannot share the spikes and surges to your house with mosfet BMS. Simple easy solution and the Winston in 60AH is cheaper then a good 140Ah AH AGM which deleivers the same cranking power, 10C=600A for 10sec straight.
all issues with LFP are already worked out, the winston above are sold for over 10years and i installed them in dozens of cars in last 10 years as only battery which run till today without any issue...and i am talking 7lV8 engines or V10 5.2l or 4.2l V10Tdi which need serious power to start and not small 4 cylinder downsize 2l Turbo jokes which a 10AH winston could start easily.

[CaptainRivet]

Originally Posted by HeinSdL

And I agree too. But here it's winter in a very miserable Genoa and I am kind of in the middle of an industrial terrain, alone! Under normal circumstances I do meet plenty of fellow enthusiasts in the various marinas where conversations are usually more about destinations and life! Not so much about an LFP/FLA hybrid set up! :-)

well that an unfortune place to be during winter...would leave the boat in the marina and crew in carrribean, that what i done last year. why suffer when you can have it better...


well the LFP is a total game changer and evertime i show a fellow sailor my 40ft the LFP install with full elecric galley, dishwasher and washing machine i even have the full attation of the admiral thats normally not interessted at all in topics like this...it a huge change and advantage for liveaboard on the hook. And if the system is simple that even the uninterested admiral gets interested because she feels secure to deal with it, she starts talking to other about it. happen to the admiral on 2 of my buddy boats...no we don't need a lithium, a washing machine and a dishwaher...3 month later, Christian that what we want to order...can you check if ok and help install...
well and after the bowtruster AGM nearly burned the boat down 3 days ago, the 2xwinston 60AH LFP ordered by the admiral are on its way to st. Martin to get rid of starter and bowtruster lead that needed to be there before at all costs...why because thats what she knew worked and LFP was new. that is the only reason people keep the lead till they screw them over and they see themselves how good and relaible LFP is. now i hear, why didn't we do this 3 years ago, would have saved us a lot hassle and bring a lot comfort which is also safety as you are relaxed instead of stressed.
and with prices of 90Euro for grade A 304AH EVE cell thats nobrainer now as even cheaper purchase cost then AGM...you don't even have to argue with cost of lifecycles...

[Pete7]

Originally Posted by CaptainRivet

well the LFP is a total game changer and evertime i show a fellow sailor my 40ft the LFP install with full elecric galley, dishwasher and washing machine i even have the full attation of the admiral thats normally not interessted at all in topics like this...it a huge change and advantage for liveaboard on the hook.

A friend has copied our install and gone hybrid after I gave him a 300w panel in return for a mornings work fitting the new 590w of panels. Another in the process of replacing his gas cooker changed direction and bought a double induction hob after seeing ours.

We have a washing machine on a 31ft yacht and I am the dishwasher on board

[RobertL]

Originally Posted by Sos

In answer to the OP's question, yes I have fitted two of them.

We have two Victron 160 AH batteries that were recently fitted as part of an insurance claim. I wanted more capacity but didn't want to replace the new batteries so went down this route. Keeps the Victron's fully charged and runs the fridge and soon the small freezer we are going to fit. We are a cat so have quite a bit of solar to keep everything topped up when sunny.
A good solution if you don't want to change your charging system and have good batteries already.

Thanks for sharing your experience. I’m not fully ready this year for LI, but I’m sure a change will come in the near future.

Thanks to all for their insights.

[Tin Tin]

Originally Posted by Pandor

Well, at least in the US you can likely replace your 300ah AGMs with at least that much LFP for around 469 Euros. This seems much easier, efficient and trouble-free to me. I found most of my existing chargers are LFP compatible. Only added a dc-dc charger from starter battery to house and left the alternator connected to LA starter.

Did the same, with recent price drop on Lithium the LifePO4 drop ins were same price as name brand AGM for same AH the only additional cost were the 2 DC DC chargers (on a Cat with standard alts and LA start ). Now got rid of propane stove and use induction.