Drop in Lithium Batteries - the basics?

[noelex]

I think that is the biggest. I would need 4 to get near the 140a which the alternator is supposed to produce.

Maybe the Sterling outputs more? And that explains the cost?

One of the aims of using a battery to battery charger with lithium batteries is to reduce the risk of the alternator overheating and becoming damaged. Unfortunately, the vast majority of stock alternators cannot put in anything like their nominal rating on a continual basis.

By deliberately selecting a battery to battery charger of lower capacity, the alternator output is capped at a level where it can operate continuously without overheating.

The safe level depends on the quality of the alternator, the installation (degree of airflow) etc, but somewhere around 50% is often chosen as a maximum value.

Thus with a stock 140A you should not be looking for a 140A battery to battery charger, but rather something like 70A or lower.

 

[lustyd]

By deliberately selecting a battery to battery charger of lower capacity, the alternator output is capped at a level where it can operate continuously without overheating.

While I agree with most of what you’re saying this isn’t actually quite right. The B2B usually goes to the house bank but the alternator also charges the start battery so is not limited by the B2B. Often the windlass and bow thruster connect direct too.

 

[dgadee]

Do you actually need 140A of charging?
On the past two years I've only used engine charging twice. With a little 18A DC-DC.
You don't have to cover every possibility.

Only the watermaker is power hungry. If I didn't have it I would not have a problem and follow your lead. Or rather I would have a water problem. We rarely use harbours.

 

[kwb78]

The B2B usually goes to the house bank but the alternator also charges the start battery so is not limited by the B2B.

A start battery will probably not pull large currents for sustained periods unless it’s really flat though. You might get 10-20A for the first 10 minutes or so, but on a small lead acid battery that will quickly tail off to a much lower value. That’s part of the reason that alternators alone are not a very efficient way of charging a lead acid battery.

 

[noelex]

While I agree with most of what you’re saying this isn’t actually quite right. The B2B usually goes to the house bank but the alternator also charges the start battery so is not limited by the B2B. Often the windlass and bow thruster connect direct too.

Yes, normally the alternator charges the start battery, and the battery to battery charger charges the house bank from the start bank.

The start battery is a small lead acid battery usually at a high SOC even after starting the main engine. The current the start battery will accept rapidly decreases after the engine starts and poses no risk of overheating the alternator.

The risk of overheating is only due to the house bank (especially if lithium, as the battery will accept a high current for long periods). The small amount of energy demanded by the start battery is insignificant. The current (and therefore the alternator heating) supplied to the house bank is limited by the size of the battery to battery charger. This is why it is important to select a battery to battery charger that is not too large, otherwise this protection is lost.

If you have a windlass and/or a bow thruster connected to the start battery rather than the house or a dedicated battery this does needs to be taken into account, although the duty cycle is quite short. Long periods of high current is what is likely to damage the alternator.

There are alternative approaches that involve a smart regulator monitoring the actual alternator temperature. These can extract more energy than a battery to battery charger, but these solutions are more involved and usually more costly.

 

[roaringgirl]

The little I know about lithium batteries says that there's no such thing as a 'drop in' replacement and I'd be wary of advice from those selling or recommending them.

 

[dgadee]

The little I know about lithium batteries says that there's no such thing as a 'drop in' replacement and I'd be wary of advice from those selling or recommending them.

That's why I started this thread.

 

[Neeves]

My memory is failing me but this, like other Lithium threads is quite long, but I had always believed, possibly erroneously that the term 'drop in' did not refer to drop in as a replacement for Lead but drop in as a replacement for making your own Lithium battery from individual cells with a selected and separate battery management system. The 'drop in' has its own built into the box battery management system (that doesn't meet the approval of many here - I think because it is less selective).

The term 'drop in' is then correct if it is assumed that the rest of the components are selected for a Lithium house bank - NOT a drop in for a direct replacement for, say, an old Lead system.

My guess, based purely on visiting a single caravan/camping/RV show and mail shots I get from retail suppliers of Lithium batteries is that most people buy 'Drop Ins'. It is simply more convenient to buy a 'Drop Ins' than order up the cells and build your own. Lithium is the next big thing for caravans and RV (much bigger than I would have thought - I was surprised) as it is for yachts but the shear volume of retailers pushing Lithium suggests a large uptake in RVs etc. A difference in the markets is that caravans don't last very long and most Lithium installations go into new builds. Some Lithium will go into older units - that maybe had no battery at all - lithium appears to have opened new market opportunity.

If 'Drop ins' have a failing it does not seem evident in the Australian 'leisure' industries.

Jonathan

 

[B27]

I think the 'drop in' label refers to these batteries being marketed as a direct replacement in things like golf carts, invalid chariots, fork lifts and the like where there is a huge established market of batteries being charged from the mains. Also, there is a pretty big market for back-up batteries in alarms, UPS's, emergency lights, sign lighting and so-on where charging is mains or solar.

Charging from a vehicle alternator is not their main market.
Reading the specs from battery makers, they don't want to know about it.
Yachts were never the main market for deep cycle batteries either.

 

[Neeves]

I think the 'drop in' label refers to these batteries being marketed as a direct replacement in things like golf carts, invalid chariots, fork lifts and the like where there is a huge established market of batteries being charged from the mains. Also, there is a pretty big market for back-up batteries in alarms, UPS's, emergency lights, sign lighting and so-on where charging is mains or solar.

Charging from a vehicle alternator is not their main market.
Reading the specs from battery makers, they don't want to know about it.
Yachts were never the main market for deep cycle batteries either.

Not disagreeing with B27, at all but

Excuse my total ignorance - I was not aware at all that the term 'drop in' used by us is a common term in a host of other applications - why would anyone here be up to date on golf carts, invalid chariots, fork lifts and the like. 'Drop in' means other things in different circumstances.

My understanding here, PBO/yachting, in terms of Lithium batteries is that a 'drop in' is characterised by an internal battery management system. (Finish, full stop - what happens in other industries may not be relevant).

Maybe those who have used 'drop ins' can comment - and clarify.

Or we need a new terminology and more clarity.

Jonathan

 

[B27]

Not disagreeing the B27, at all ut

Excuse my total ignorance - I was not aware at all that the term 'drop in' used by us is a common term in a host of other applications - why would anyone here be up to date on golf carts, invalid chariots, fork lifts and the like. 'Drop in' means other things in different circumstances.

My understanding here, PBO/yachting, in terms of Lithium batteries is that a 'drop in' is characterised by an internal battery management system. (Finish, full stop - what happens in other industries may not be relevant).

Maybe those who have used 'drop ins' can comment - and clarify.

Or we need a new terminology and more clarity.

Jonathan

Actually, not many battery makers/sellers are using the term 'drop in'.
Here's an example of one who does:
Archief Toepassingen - Battery Supplies
Their list of applications is significantly devoid of caravans, floating or otherwise.

If you google 'drop in battery' you get a lot of returns for power tool batteries and the like which 'drop in' to the charger. And not much which looks like a 'car battery'.

 

[Kelpie]

The 'drop in' has its own built into the box battery management system (that doesn't meet the approval of many here - I think because it is less selective).

Good quality 'pre assembled' batteries are not a problem.
I chose to build my own almost entirely due to the cost savings.
Back in early 2021 when I built the first one, the cost savings were significant. My more recent one is still about a third cheaper.
A DIY battery is also significantly more compact. A friend bought some batteries at the same time as me and his 300Ah units are about twice the volume of my 280Ah DIY one.
Another important point is that you can specify the BMS and cables to suit your needs- if you only need low current then you can save some money.
Finally, if running a high power BMS you can have much better ventilation and cooling, because it's not all sealed up in a box.

 

[st599]

Please Google Lithium Batteries and airlines. You may only carry anything with Lithium batteries as hand luggage, you are not allowed under any circumstances to place them in your suitcases. I wonder why???

This isn't correct. You can put Li-Ion batteries in the hold, provided they are less than 100Wh, they are connected to equipment and they have a UN/IATA restricted goods test certificate.

Then you can hand carry up to 20 more certificated batteries.

Air Transportation of Li-Ion Batteries | PAG Ltd - Intelligent Linking Batteries

 

[Neeves]

Good quality 'pre assembled' batteries are not a problem.
I chose to build my own almost entirely due to the cost savings.
Back in early 2021 when I built the first one, the cost savings were significant. My more recent one is still about a third cheaper.
A DIY battery is also significantly more compact. A friend bought some batteries at the same time as me and his 300Ah units are about twice the volume of my 280Ah DIY one.
Another important point is that you can specify the BMS and cables to suit your needs- if you only need low current then you can save some money.
Finally, if running a high power BMS you can have much better ventilation and cooling, because it's not all sealed up in a box.

1/3 cheaper is still significant. I don't know how you determine if pre-assembled batteries are good ..... or not. Most of this kit, except Victron, is new, new players or old players entering a new market. They might be reputable but whether they know the detail on lithium - I don't know. I can already pick holes in the background to specific 'retailers' which does make me wonder.

I'm not so concerned about size. My 200Ah Lithium with internal management is about 2/3 the size of one of my 200Ah Lead batteries but the single Lithium's available power is roughly similar to that produced by the 2 Leads we had as house. The big saving is between Lead and Lithium and that saving on space, in terms of usable power, with Lithium is huge. I also like the large savings on weight.

I've been checking temperature of the Lithium and its been always cold or 'room' temperature - nothing to be excited about. But I'm not stressing the Lithium yet, simply running a big ice box, as we had to wait for success with the meter to know what we were doing. Now that we have the meter up and running - we would not be without it (which is what I had anticipated) we will slowly stress the Lithium by using more of the available power - and then the battery may warm up. I have computer fans 'ready' if we feel we are generating too much heat.

I'm not knocking making your own, nor praising batteries with an internal BMS - but I recognise I'm not an expert and building a battery is outside my job description (or
CV).

I may change my mind over building - but one step at a time.

My next little project as part of this project is making a second bus bar, this time for the positive battery pole (thanks to Paul Rainbow, and someone whom I have forgotten) who both said restrict a single cable to the battery pole. I'm happy to be doing all this as I have found my original ideas were wrong, or bad practice, and my original arrangement does not allow me to sensibly add the positive bus bar, no room - but because its 'experimental' I can the change it when it is eventually installed (currently its in a big box with the esky in another box - with the solar panel on the roof). I have already added a computer fan to the esky box as it does get warm - it had no ventilation and sat in the sun.

Jonathan

 

[noelex]

I'm not so concerned about size. My 200Ah Lithium with internal management is about 2/3 the size of one of my 200Ah Lead batteries but the single Lithium's available power is roughly similar to that produced by the 2 Leads we had as house. The big saving is between Lead and Lithium and that saving on space, in terms of usable power, with Lithium is huge. I also like the large savings on weight.

For a camper trailer the most important factor is to maximise solar input.

Unlike on sailboats, solar panels can be arranged on the ground around a camper trailer. Solar panels are not expensive so this is generally the best solution. This is not practical on a sailboat because the water is in the way.

Sailboats unfortunately can’t arrange solar panels "on the ground" around a campsite.

 

[Neeves]

For a camper trailer the most important factor is to maximise solar input.

Unlike on sailboats, solar panels can be arranged on the ground around a camper trailer. Solar panels are not expensive so this is generally the best solution. This is not practical on a sailboat because the water is in the way.

Sailboats unfortunately can’t arrange solar panels "on the ground" around a campsite.

You seem to have a fetish about camper trailers (and also about what we are doing). I don't think our one, 250 watt, folding, solar panel would be difficult to arrange on a yacht, foredecks are usually empty. I can assure you climbing onto the roof of a house to maximise the farming of solar energy is not easy - and I do not do it. The panel sits up there and is not moved - a bit like a solar panel on a yacht (except we have trees instead of a mast and boom shading part or all of the panel.

My wife has pointed out you mentioned, here on YBW, we had sold our catamaran, I recall 3 times, as the ink on the contract was drying. Your news was so new we were still waving good bye to 'Josepheline' and the new owners as I read the first update from you. What prompted you, at all, to update forum members - so quickly. Why was it so important.

It is not unusual for people to sell their yacht and then take their time in deciding what they will replace her with. You are now desperate to know why we are working on a Lithium power bank. To me, with minor differences, a lithium power bank in a motor home would have more similarities than differences to one in a yacht. There is a huge resource here, from people I know of, trust and respect, with knowledge of lithium installations. As a member here for some time now I am asking the advice of that expertise - its up to me to decide if the information is relevant - which is the case for anyone asking advice. Reading the posts on Lithium installations there are members here who are voluntarily sharing their experiences with Lithium, they obviously enjoy sharing (or they would not post in such detail).

I know that my choice of a battery monitor is small beer - but it makes a change to have someone buy a cheap as chips unit, and try it, instead of the factorially more expensive Victron everything - not everyone lives under a Pagoda tree.

Don't you have anything better to do?

I would prefer, as might other members, that instead of interrogating me in a manner that you do not do of others and you considered answering the outstanding questions on your choice of anchor and its unusual characteristic of shallow setting. If this is not easy why not tell us about your current anchorage, any problems you have had since the new yacht was launched, how your own power bank has been as good as you envisaged etc.

My wife does wonder if you are stalking us.

Jonathan

 

[Neeves]

I was mulling over Lithium installations and considering the similarities to our Lead installation on Josepheline and installation in, lets call them Leisure Vehicles. I thought outside these perameters and included my thoughts on one of our newer members Gifth who has both a motor home and a trailer yacht which he uses 'together'.

My first thought was that some installations are large enough to power a small family home - so what happens to this resource when the owners are not in the Caribbean, Mediterranean or ....Australia. The investment has been made and this small power station sits idle - but maybe they have thought of this and plug their power station into the grid....?

Grifth is not alone in owning a Motor Home and a Yacht - and using both regularly. So Grifth, and others, could have 2 power stations, both largely solar powered (most motor homes have a flat roof (like a catamaran) but space for solar does not seem an insurmountable problem for some (but maybe they have big yachts....?)

So we have small, privately owned, power stations that may sit idle - in times when we are being urged to be environmentally friendly and energy prices are rising.

The other wasted resource is the duplication of systems - a live aboard yacht, whether lead or Lithium (but this post is really focussed at new installations so Lithium) has much the same kit as a motor home and many are big enough to power a small home - so why not make a domestic power station that can be simply moved from home to motor home to yacht - a power station in a box, or couple of boxes.

I accept the idea may work better in places known for lots of sun, Australia comes to mind - So plug the motor home into the house (and/or electric car).....?

Build the hardware into a box with quick connect inlet/outlets for cables, another box with batteries but have separate solar panels.

Daft idea....?

Jonathan

 

[noelex]

You seem to have a fetish about camper trailers

Jonathan

The electrical system of a camper trailer is not the same as a yacht. Before starting cruising full time I owned a camper trailer in Australia for many years and installed most of the electrical and solar system, so I am familiar with both.

There are some areas of similarity, but there are also some important differences. Some of these differences can create safety problems if different practices are not followed.

I do not understand why you want to hide from forum members that this lithium system is for a camper trailer (If this is correct). You will receive the incorrect advice trying to disguise this information. Of greater concern, members will be encouraged to follow your advice and copy aspects of your lithium system without realising your experiences are based on what works well on a different platform.

Why not simply point out that this is a camper trailer system? Why do you not want forum members to know this? I don’t think anyone will object to giving you advice, even though this is not a marine system. More importantly, armed with that knowledge their advice is more likely to be helpful. When members are weighing up if they should take into account your views and experiences, with a lithium electrical system such as your recent thread on installing an inexpensive battery monitor they will be able to correctly consider if this advice is applicable to their installation on a yacht.

 

[noelex]

My wife has pointed out you mentioned, here on YBW, we had sold our catamaran, I recall 3 times, as the ink on the contract was drying. Your news was so new we were still waving good bye to 'Josepheline' and the new owners as I read the first update from you. What prompted you, at all, to update forum members - so quickly. Why was it so important.
Jonathan

I first noticed your catamaran was listed for sale over five months ago. It was already sold at this stage so must have been sold earlier than this. I did not say anything for many months. I was surprised in the meantime to see you post in multiple threads about lithium batteries, wiring practices and solar panels directly indicating these questions were about installing these systems on (your now sold) catamaran. Many members took the time to answer these questions assuming this was the case. Upon finding out the real situation Paul Rainbow summed up the feeling of many members when he posted:


"Now you say it's going to be used in a house. This, to my mind, is dishonest. You have allowed to thread to go on for 49 posts, with all contributors under the impression that you plan to use the cable for a roving panel on deck, in fact that is also what you said.
That's bad."

Paul is a specialist in marine electronics. In my opinion, you owe him (and other members) the courtesy of pointing out any questions and observations that do not relate to marine installations. As well as a simple courtesy, the answers provided will be better and members conclusions based on your experiences will be more accurate.

When posting questions or observations about non marine systems in the Practical Boat Owner forum you should make this clear in my view.

Now let’s get back to discussing lithium drop-in batteries.

 

[Neeves]

I first noticed your catamaran was listed for sale over five months ago. It was already sold at this stage so must have been sold earlier than this. I did not say anything for many months. I was surprised in the meantime to see you post in multiple threads about lithium batteries, wiring practices and solar panels directly indicating these questions were about installing these systems on (your now sold) catamaran. Many members took the time to answer these questions assuming this was the case. Upon finding out the real situation Paul Rainbow summed up the feeling of many members when he posted:


"Now you say it's going to be used in a house. This, to my mind, is dishonest. You have allowed to thread to go on for 49 posts, with all contributors under the impression that you plan to use the cable for a roving panel on deck, in fact that is also what you said.
That's bad."

Paul is a specialist in marine electronics. In my opinion, you owe him (and other members) the courtesy of pointing out any questions and observations that do not relate to marine installations. As well as a simple courtesy, the answers provided will be better and members conclusions based on your experiences will be more accurate.

When posting questions or observations about non marine systems in the Practical Boat Owner forum you should make this clear in my view.

Now let’s get back to discussing lithium drop-in batteries.

You must be really bored, you follow advertising of Lightwave cats, you follow the sale on one specific cat, you feel the need to announce same here, 3 times, you then get a fixation on caravans, camping trailers - what a sad life you lead.


My lithium battery system is not to be used in a house. The solar panel on the roof was to power the system I was, am, developing. Coincidentally the panel failed and we are replacing it today, under warranty. The panel was located on the roof because that is 'unused' space and gets full sun from about 9am to about 2pm, before and after the roof is shaded by trees. I don't bother to align the panel to get the most of the sun - its too much of a faff to climb a ladder onto the roof and move the panel'. The panel is powering the Lithium system I have developed and I'm using a 65l esky to provide a power draw it uses around 6amps on its cycle. I could used the same panel, or multiples of same on a yacht, foredeck, hinged on stanchions.

The lithium battery system is being developed to be used in a 'mobile' application - one where I can move the base components, the battery and in this case one folding panel 250w (but could be more) to a yacht, motor home, trailer etc. I have specifically wired such that the base components are all arranged adjacent to each other and the inputs and outputs are via Anderson plugs. I can pick the base units up as one 'device', the battery, only 1 x 200amp/hr (so far) and the one panel. The battery is significantly lighter than the 200amp/h we had on Josepheline, the panel I find surprisingly heavy compared to the flexible panels we had on Josepheline.

I could pick up the whole assembly as 3 items - and put on a yacht or caravan tomorrow - its would probably take a day faffing about to get it secured and connected.

The ONLY unit I have described in any detail is the battery mon - and it is identical in how it performs to the one we used on Josepheline for 25 years. The one we bought is said to be waterproof - most make no such claims. I have made no comments on the components I am using, most are branded by Australian distributors (but made in China), so of little interest to most in the UK. The unit can be powered, or the battery can be powered, by a B2B off an alternator or solar. I'm not giving up on wind but have not included it so far. The battery has an internal management system. The unit has a small 1,500 watt inverter. When we extend we will use identical units.

You and Paul jumped to incorrect conclusions. If, when, I discover that my ideas need to be modified for use in a mobile home, camper trailer or yacht - I'll post same. Currently I can find not a single difference between the applications, except it needs to have, maybe another battery, matching the current battery, and definitely more solar panels. Based on recent development of thought processes I'm wondering about charging an electric car - if we increase the number of panels - but this would involve different components (not used in the other applications).

The cable thread was specifically for a yacht, as we are planning for the future. The conclusion Paul came to, domestic house was wrong, as are your guesses, and his response was unworthy of him and anyone else on this forum. I had misjudged him. You remain true to form, making wild guesses.

So my concepts include a yacht and our ownership of Josepheline and living on her for 3 months at a time is the foundation and remains the foundation of our ideas.

If this was all for a house I'd have approached differently to ensure I could benefit from the Government subsidy on home solar. We don't have an electric car - so its a long term and only a recent thought.


Hopefully now you can forget about me, though I think I am a thorn in your side having exposed your anchor error (and this is the main motivation for you and your negative thoughts. Sadly it seems that the sore you feel will never be healed - and that is YOUR burden). Maybe if you had allowed dissenting thoughts you would have known about the shallow setting angle - burning books never works - it comes back to bite you.

Jonathan