Lithium battery installation after rash purchase???

[stav]

Hi All, HNY.

Before the festive season I was lured by a black Friday deal and bought two Lipo batteries for a good price. 100Ah each I have also bought a 60A DC to DC charger.

I have just semi retired (from teaching to being a carpenter) and my pension will kick in in a years time. I then hope to go off sailing for the summers, from UK, to perhaps Spain, Ireland, Scotland etc. ,mostly singlehanded as my family are not interested.

Therefore I was interested in using the powered autohelm as don't feel a windvane is cost effective (although looking to see if I can build one such as the BB design). Also I have a ketch rigged Conway and a windvane will mix up with the mizzen boom.

Therefore I was thinking of getting Lipo batteries to drive the autohelm for up to 24 hours and then be able to recharge the batteries quickly from the engine or a small generator.

Hope that all makes sense?

Currently I have 3x 110AH lead acid in the domestic bank and 1x 100Ah starter battery. There is also an Adverc battery management system which seems to do a good job of keeping them at 100% but I rarely let them discharge below 80%. I also have a good sized shore charger 80 or 100amps??

Therefore I am seeking advice on the best way to incorporate the Lipo in to my system? Currently thinking of taking out two of the domestic LA batteries and putting them together as the starter batteries (to act as reserve domestic if need be and there is space for two batteries in the locker with the one battery).

Then to add the two Lipo batteries to the single LA with a switch between the LA positives and the parallel Lipo each with a separate voltage display to check the voltages are not miles apart? Then engine off connect the switch and run domestic services from the LA and Lipo. Before switching on engine disconnect switch, start engine and DC to DC will charge the lipo batteries (or the shore charger will).

Hope that makes sense. Biggest problem is switch but will change the manual switch for a remote battery switch so can operate from cockpit.

I will add some pictures if I can..................

I have searched the internet and youtube but seem to find so much contradictory advice and most seem to involve solar panels in warm clims...... But looking for a solution for our climate without solar and not needing air-conditioning or freezers.....

Thank you if you have worked through all of that and for any suggestions!!!!!

 

[Tranona]

Suspect you will get a variety of suggestions, but my first thought would be why you think you need a house bank of more than the 330Ah that you have now? Have you done an audit of daily consumption and your estimated power generation in that period? The biggest challenge on passage is probably generation rather than storage capacity - in other words minimising your net consumption. So adding solar is probably the first step to reduce your reliance on the engine. I assume you have an old style alternator as you have an Adverc to boost the voltage and if the current batteries are in good condition I suspect your current setup would more than cope with your autopilot, basic instruments and fridge in the typical mix of sailing and motoring.

The lithium will of course give you greater usable capacity and faster charging in a smaller space, but what really pays off is if you have solar which even in northern latitudes in the summer will provide a useful amount - and that works with LA as well.

 

[Spanjaard]

I was researching this for a while on Youtube.

But instead of going from the battery pack these guys are installing LiFeP04 independent cells interconnected as required to a fraction of the price.

This is a very explicative video of a guy setting a LiFeP04 battery bank with over 60 battery cells:

 

[Spanjaard]

Part 2:

And this another guy with diagrams for installation:

 

[garymalmgren]

Therefore I was thinking of getting Lipo batteries to drive the autohelm for up to 24 hours

There is an alternative to the 24 hour autohelm. Sheet to tiller.
Takes a bit of fiddling but satisfying when you get it going.
Even if not used as often as an autopilot it is a great backup.
gary

 

[Refueler]

Boy - I was really worried for you till I looked at your picture of the batterys ...

Why ? You typed LiPo ... which is a completely different battery to LifePo .. and totally unsuitable for what you wanted.

LiPo would need a LiPo programmable charger to service it ... with balancing and management. LiPo can easily power items on board as a 3S pack sits at 12.6V max charged .. but should not be maintained at full charge when resting ... they need to be reduced to 3.7 - 3.8V per cell when not in use.

But LiFePo is getting more common and suitable management systems are available ...

I will leave that part to others ...

 

[B27]

I suggest measuring the capacity of the existing house batteries.
If they are past their 'use by date', it simplifies the problem perhaps?

 

[lustyd]

Some very weird responses on this thread, wildly off topic and very unhelpful to the OPs actual question.

@stav I would suggest you don't mix your battery types. Your two 100Ah lithium will give more usable capacity than the current bank, so just remove the current bank. Remove any connection to the alternator other than through the B2B charger (hopefully it's a charger, not power supply!). This includes split charge relays and VSRs, be sure to look closely at your wiring so you're certain these are not present.

If you want to have two lead batteries for start then better to match them and use the existing house ones if they are a suitable type of lead battery.

Your shore charger will charge either the lithium or the lead if it's a single output, and even if not it will almost certainly only do one charge profile at a time so you need to choose. You can connect it to the start bank and let the B2B charge the house, but this is slow and inefficient usually. If you charge the house bank, there's no way to charge the start from that - not a problem but something to be aware of. You also shouldn't leave the lithiums charging, they don't like to be full and topped up so make sure you switch off when you leave the boat or you'll kill the lithiums. In theory the BMS will prevent issues here, but until lithium gets cheaper better safe than sorry! Set the max voltage on the charger to 14.2 and use a lithium profile, you won't lose much capacity but it's kinder to the batteries.

 

[Refueler]

Some very weird responses on this thread, wildly off topic and very unhelpful to the OPs actual question.

@stav I would suggest you don't mix your battery types. Your two 100Ah lithium will give more usable capacity than the current bank, so just remove the current bank. Remove any connection to the alternator other than through the B2B charger (hopefully it's a charger, not power supply!). This includes split charge relays and VSRs, be sure to look closely at your wiring so you're certain these are not present.

If you want to have two lead batteries for start then better to match them and use the existing house ones if they are a suitable type of lead battery.

Your shore charger will charge either the lithium or the lead if it's a single output, and even if not it will almost certainly only do one charge profile at a time so you need to choose. You can connect it to the start bank and let the B2B charge the house, but this is slow and inefficient usually. If you charge the house bank, there's no way to charge the start from that - not a problem but something to be aware of. You also shouldn't leave the lithiums charging, they don't like to be full and topped up so make sure you switch off when you leave the boat or you'll kill the lithiums. In theory the BMS will prevent issues here, but until lithium gets cheaper better safe than sorry! Set the max voltage on the charger to 14.2 and use a lithium profile, you won't lose much capacity but it's kinder to the batteries.

I would caution all responses - with greatest respect - OP has mixed up LiPo with LiFePo ... this indicates a lack of knowledge on Lithium base ..

He has come here to get advice ... no disrespect intended to OP at all.

 

[stranded]

Some very weird responses on this thread, wildly off topic and very unhelpful to the OPs actual question.

@stav I would suggest you don't mix your battery types. Your two 100Ah lithium will give more usable capacity than the current bank, so just remove the current bank. Remove any connection to the alternator other than through the B2B charger (hopefully it's a charger, not power supply!). This includes split charge relays and VSRs, be sure to look closely at your wiring so you're certain these are not present.

If you want to have two lead batteries for start then better to match them and use the existing house ones if they are a suitable type of lead battery.

Your shore charger will charge either the lithium or the lead if it's a single output, and even if not it will almost certainly only do one charge profile at a time so you need to choose. You can connect it to the start bank and let the B2B charge the house, but this is slow and inefficient usually. If you charge the house bank, there's no way to charge the start from that - not a problem but something to be aware of. You also shouldn't leave the lithiums charging, they don't like to be full and topped up so make sure you switch off when you leave the boat or you'll kill the lithiums. In theory the BMS will prevent issues here, but until lithium gets cheaper better safe than sorry! Set the max voltage on the charger to 14.2 and use a lithium profile, you won't lose much capacity but it's kinder to the batteries.

Slight thread hijack but hopefully helpful to the op as well… On the setup I am planning, in winter I expect to need to leave the lifepo on solar charge when I leave the boat - will it be safe (for the battery) to do that if I set the Victron moot controllers to single stage charging with max voltage somewhere in the half full range?

 

[Tradewinds]

The OP might find this of interest.

 

[Tranona]

Therefore I was thinking of getting Lipo batteries to drive the autohelm for up to 24 hours

There is an alternative to the 24 hour autohelm. Sheet to tiller.
Takes a bit of fiddling but satisfying when you get it going.
Even if not used as often as an autopilot it is a great backup.
gary

Can you explain how that would work on a centre cockpit wheel steered ketch such as the OP has?

 

[geem]

I would not advice anybody to install the type of lifePO4 batteries you have purchased. These are poor quality batteries. They have no bluetooth or active balancer. They are suitable for a camper van but not a yacht.
On cheap poorly matched cells, such as those in this type of battery, there is a risk of a single cell going rogue. The cheap passive balancers installed in these battery types, often can't cope with a large voltage deviation from one cell to another. For this you need an active balancer. Bluetooth, that allows you to see the individual cell voltages would alert you to a problem. You have neither with these batteries. The risk is battery shut down. When this happens you have no clue as to why its happened.
One of the reason why these batteries tend to go out of balance is aggressive charging. Using a shore power charger at high amps would increase the risk of a cell imbalance that the passive balancer could not correct. They would run more happily on solar with its more gentle charging characteristics.
If anybody reading this thread is contemplating lithium batteries, please do not buy the cheapest batteries you can find for your boat. Buy batteries with bluetooth and an active balancer or build your own batteries from gradeA cells and use a good BMS like a JK with 2A active balancer.
You need to be able to insure your boat. Read the American standard ABYC tm13 or the equivalent ISO standard for installation of lithium in boats. These standards demand a high quality of installation. Complying with the requirements is expensive and time consuming but they do ensure a safe and reliable installation. Sorry to the OP. There is a lot to learn and understand when converting to lithium from lead.

 

[Tranona]

I suggest measuring the capacity of the existing house batteries.
If they are past their 'use by date', it simplifies the problem perhaps?

Indeed.

Very much a question of "I would not start from here". No suggestion so far that the current batteries need replacing so the basic question is whether the current set up is appropriate to the proposed usage pattern. If not then what is the best way of improving it. Adding 2 lithium to what is at the moment not a particularly good system is maybe not the right way to go.

 

[lustyd]

I would caution all responses - with greatest respect - OP has mixed up LiPo with LiFePo ... this indicates a lack of knowledge on Lithium base ..

He has come here to get advice ... no disrespect intended to OP at all.

They bought the right thing, I think arguing the detail is pointless. They are asking for help on how to implement what they have, and that doesn't require power calcs, capacity planning or attaching a tiller to a sheet, it requires advice on where to put things and what else they may need. I answered the direct question and have to assume they are competent enough to wire it in.
I suggest if not, then OP should ask for more detail about fuses etc. and we can help further, but it's too late to talk about capacity - the batteries have been purchased and have greater usable capacity than the current bank so all good.

 

[lustyd]

Slight thread hijack but hopefully helpful to the op as well… On the setup I am planning, in winter I expect to need to leave the lifepo on solar charge when I leave the boat - will it be safe (for the battery) to do that if I set the Victron moot controllers to single stage charging with max voltage somewhere in the half full range?

If there's a BMS in the battery it'll be safe enough and if you leave the voltage low enough it won't overcharge. I left mine on the solar this winter and it's usually at 99% when I return. Time will tell whether I'm shortening the battery life

 

[dunedin]

You are right to go with an electronic autopilot - particularly if there is any way of installing a below deck system (not sure if your boat is wheel or tiller steered). We have done at least 15k miles coastal cruising under autopilot in the areas you are planning

However, we have never bothered (yet) with changing the batteries. Instead the first priority I would suggest is finding a way to install some solar power, We have just 150w of panels plus MPPT controller, but so far never had an issue keeping up with demands of autopilot, twin chart plotters etc and a fridge on 7x24. If on anchor for more than a day we tend to run the engine anyway, but that is necessary to get hot water for the showers.

One thing I would suggest you check out carefully is insurance, for two reasons. You mention singlehanding and running the autopilot for 24 hours. You may struggle to get insurance for more than 18 hours solo.
Also, many insurers are suggesting that they may not cover DIY Lithium battery installations, unless inspected and signed off by a qualified professional. This seems to be increasingly common for DIY batteries intended for electric propulsion, but also heard sometimes applied to domestic batteries only. It certainly could be considered a modification which should be reported to the insurers. Many of the YouTube video types may be on third party only insurance, or risking it.

Enjoy your voyage, should be great experience.

 

[geem]

If there's a BMS in the battery it'll be safe enough and if you leave the voltage low enough it won't overcharge. I left mine on the solar this winter and it's usually at 99% when I return. Time will tell whether I'm shortening the battery life

You are shortening thr battery life. By how much, I am not sure. They are best stored at 50%. There are a number of other factors that influence this. The temperature being the main one. Since you are storing at low temperature and close to 100% SOC it won't be as bad as high temperature and 100% SOC.
It will lose some capacity but maybe not so bad in the scale of things. If you are not using the boat over the winter dropping the SOC to 50% would be prudent

 

[lustyd]

You are shortening thr battery life. By how much, I am not sure. They are best stored at 50%. There are a number of other factors that influence this. The temperature being the main one. Since you are storing at low temperature and close to 100% SOC it won't be as bad as high temperature and 100% SOC.
It will lose some capacity but maybe not so bad in the scale of things. If you are not using the boat over the winter dropping the SOC to 50% would be prudent

We use the boat all year around. It's not practical or desirable to leave them at 50% so this is the best compromise I could come up with. They're not being rammed with power so unlikely to puff up, and a bit of capacity loss is better than starting every trip with a lengthy recharge. Either way it's a million times better than the old lead system
I don't tend to charge them while on the boat so most of the time they will be lower than that as in winter it'll take days/weeks to get them up to 99%.

 

[geem]

Deleted. Duplicated post