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Battery Charging 'Concept' advice


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12 hours ago, Pompey said:

You go full Li-On or nothing really.

 

I disagree.

 

I think there is a lot to be said for a small lithium battery being used to bring the LA bank up from 85% to 100% every few nights, totally SILENTLY.

 

This reduces engine running time substantially thus massively saving on fuel and will be vastly cheaper than a full-sized lithium-only installation.

 

 

Edited by Mike the Boilerman
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13 hours ago, Pompey said:

You go full Li-On or nothing really.

I don’t agree. For the reasons already given, a hybrid system can offer worthwhile advantages. 
 

What LifePo4 system have you installed?

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53 minutes ago, WotEver said:

I don’t agree. For the reasons already given, a hybrid system can offer worthwhile advantages. 
 

What LifePo4 system have you installed?

 

Judging by the spate of incorrect information in a number of posts on various battery subjects, I would question anything he suggests unless the information is supported by  at least one other member who has a history of giving correct advice.

Edited by Alan de Enfield
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17 hours ago, Pompey said:

You go full Li-On or nothing really.

 

 

 

I'm going to add to the disagreement on this...

 

I already run something of a hybrid system - laptop, phone, radio, tv, mp4 player + speakers are all run from their own internal batteries (charged during the time it takes to charge the lead acid batteries) thus reducing the draw on the LA batteries making sure they don't ever get too depleted on a given day.

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1 hour ago, StationMaster said:

I'm going to add to the disagreement on this...

 

I already run something of a hybrid system - laptop, phone, radio, tv, mp4 player + speakers are all run from their own internal batteries (charged during the time it takes to charge the lead acid batteries) thus reducing the draw on the LA batteries making sure they don't ever get too depleted on a given day.

Me too :)

 

Ive just installed 530Ah of LiFePo4 batteries, and have retained my much reduced capacity Lead Acid Bank.

 

The Li Bank are connected to the domestics, and charge only from the 240v charger at present. The LA bank are connected to the inverter, and charge from the alternator and solar. If I want to charge the Li bank from the alternator, I’ll fire up the inverter and connect the 240v charger to a 240v socket - no danger of frying the alternator with this setup :) 

 

Things will no doubt evolve as time passes. I will definitely want the Li bank charged by solar when Spring comes, and I may even want it to power the inverter in time.

 

My point is that it is a very hybrid system, which resolves some of the issues with a purely Li system, and shows that it is definitely not all or nothing, when it comes to lithium :) 

 

I also can’t see any problem with charging/topping up the LA bank from the Li bank. Seems very sensible!

 

 

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And of course nearly all of the members here using lithiums (peterboat excepted) have connected them in parallel with at leat one LA battery anyway, as a rough and ready way of protecting the alternator in the unlikely event of an emergency disconnect during charging from the alternator.

 

So a hybrid system is actually forum 'received wisdom'. 

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38 minutes ago, Mike the Boilerman said:

So a hybrid system is actually forum 'received wisdom'. 

Not just this forum. It’s a widely adopted practice. Even Kevin at Onboard Energy does it. 

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On 05/01/2020 at 00:04, rogeriko said:

Your perfect Concept Battery system would be a Li-Ion battery bank from an electric car. These hold around 50kwh+ of power, enough to run a narrowboat for a week. This could be charged by a 50kw generator coupled to the engine in an hour. Just imagine only running the engine one hour once a week. Of couse most engines could only run a 10kw generator but this would still only need to be run for an hour or two every 3 or 4 days.  14hp is about 10kw.  Of course a proper generator would need to be coupled to the engine with a clutch system at a 1 to 1 ratio running at 1500 rpm.  Batteries from crashed electric cars are available for a couple of thousand and generators are cheap. Lets see who will be first to build it???

Er....there are quite a few of us doing this already.

 

Ok, I only have 6KWhr pack but its from a crashed car and was cheap second hand. No drama at all!

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On 04/01/2020 at 19:00, StationMaster said:

 

This leads me to think that when the washing machine isn't running and the engine/generator is running, lots of power is being wasted. Was thinking maybe I could store this power in a Lifepo/lithium type of battery connected to the 240v and say connected via a switch to run the freezer or fridge which run on 12v. I don't want to convert the whole boats battery system and charging system until prices come down for people who would need others to take on that level of work.

 

 

On 08/01/2020 at 23:05, Pompey said:

You go full Li-On or nothing really.

 

A complete waste of money mixing the two systems. 

 

Some peeps post some very bad advice on here. A waste of money mixing LAs with LiFePO4s? Nah. Excellent cost benefit. I would love to hear Pompey's experience to back up his statement.

 

In response to Stationmasters OP, I think what I have done is pretty near to what he is wanting. The outline of my system was in this thread (page 9, post 212) although there have been some changes since posting.

 

The more upto date system was described in January's 2020 edition of Canal Boat Magazine. What I did was to bolt on 480Ahrs of LiFePO4 capacity in parallel to my 660Ahr LA bank. When I bought the 12 LiFePO4 cells I wasnt sure they would be compatible with the alternator charging and didnt want to disrupt the existing battery system and charging, so I just connected them up together with a big isolation switch between the two banks. The system has now been in use for 10 months. I run it between 12.8V and 13.2V on discharge so the LA bank is always at least 95% full. That means the Li bank always has the capacity to take whatever is thrown at it and could do SM's job of taking power from the TP etc. The benefit of leaving the LA's in place is that when I leave the boat, or one of our sprogs want a week out in it, I can isolate the Li's and let them use it just on the LA's. If we sell the boat I will just unbolt the wires and take the Li's with me.

I am now totally reliant on the LiFePO4s but have the option to switch back to LA's. I will never go back to LA's only. In time as the LA's die (no sign yet) I will take them out of circuit.

 

The system was put together using off the shelf stuff and was simple to do once I had got my head around making 50mm battery connections. Total cost was around £1250 but this could be reduced by going for just 240Ahr or 360Ahr Li cells. Even at £1250 this will pay back for itself in 5  years with much, much reduced engine running (cost of diesel only). Factor in engine hours, servicing and noise reduction and the benefits get much better.

 

The OP shouldnt be frightened of looking at a hybrid system like this if he understands the need to learn about lithium voltages and charging and be prepared to spend a bit of time monitoring in the first few months of operation.

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12 hours ago, Mike the Boilerman said:

And of course nearly all of the members here using lithiums (peterboat excepted) have connected them in parallel with at leat one LA battery anyway, as a rough and ready way of protecting the alternator in the unlikely event of an emergency disconnect during charging from the alternator.

 

So a hybrid system is actually forum 'received wisdom'. 

 

received wisdom indeed, Lithium burns with no air, along with a higher temperature than steel will remain intact.

 

it is inevitable we are going to recycle battery cells. I would 'IMHO' check a number of things, 1st your insurance policy.

 

 

 

 

 

 

 

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1 minute ago, Pompey said:

 

received wisdom indeed, Lithium burns with no air, along with a higher temperature than steel will remain intact.

 

it is inevitable we are going to recycle battery cells. I would 'IMHO' check a number of things, 1st your insurance policy.

 

 

LiFePO4 batteries being the exception to this, which is why they are being widely adopted in electric cars and in aircraft.

 

 

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On 05/01/2020 at 10:46, StationMaster said:

Your point was relevant. However if I reduced drain on the LAs to 5% per day then charge time would be reduced - IF I found a simple solution to running the fridge and freezer with built in protection that would charge quick enough and could be simply wired in by a 2 or 3 way switch then this would feasibly reduce chardging time significantly. However I don't think there is that solution available yet.

 

I didn't think there was a tv that would run for 10 hrs on a 2 hour charge until someone here mentioned it - perhaps in the future a fridge that runs for 24hrs on a 1 hour charge to it's own internal battery will be possible.

 

Incidentally a sunny winters day does make a difference to how well the batteries are charged so solar is not completely useless in the winter ?

Just to mention that LA batteries aren’t as simple as a “bucket model” (bucket which is full of water at 100%SoC and empty at 0% SoC.

The plates are a spongy material and as such, have depth - some of the reactive material is on the surface, some deep inside. Over time, the chemicals diffuse through the sponge so that the concentrations are equalises, but this takes quite a long time.

 

In other words, there is a big difference between discharging 5% in a short time, then immediately recharging, vs discharging 5% slowly, leaving the battery for a while, then recharging.

 

In the former case, only chemicals from the surface of the plate are used in the discharge, and these are easily and rapidly replenished on charge.

 

In the latter case, over time the chemicals from the interior of the plate slowly diffuse out to equalise the concentration throughout the plate. On recharge the surface of the plate is quickly replenished, but it takes a long time on charge before the charge diffuses into the interior of the plate.

 

So in the latter case, if the charge is stopped after the same time it took to charge the former case, some sulphate remains in the battery and over time and repeated cycles, this builds up to hard sulphate and the battery loses capacity.

 

In summery, recharge time is not just about the depth of discharge, it is also about the time the batteries are left partially discharged.

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3 hours ago, Pompey said:

 

received wisdom indeed, Lithium burns with no air, along with a higher temperature than steel will remain intact.

 

er..........Lithium burns with oxygen. It can burn "ie be consumed" by itself if you raise the temp to over 2 million degrees Kelvin. My bote does not get that hot.

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1 minute ago, Dr Bob said:

er..........Lithium burns with oxygen. It can burn "ie be consumed" by itself if you raise the temp to over 2 million degrees Kelvin. My bote does not get that hot.

Be careful - he has a sestificate that says he can connect wires to battery terminals !!!!!

 

Have you got one ?

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3 hours ago, Pompey said:

Lithium burns with no air...

How does it do that then? Burning with no oxygen is a pretty clever trick. 
 

Of course that doesn’t even address the fact that you’re wrong about LifePo4 batteries which are virtually impossible to ignite. 

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3 hours ago, Alan de Enfield said:

He is a professional boat electrician :

 

Screenshot_20200110-063055.png

You have to remember that to achieve this status requires a serious commitment of a whole day’s attendance on a course. 

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1 hour ago, WotEver said:

You have to remember that to achieve this status requires a serious commitment of a whole day’s attendance on a course. 

I have never doubted this. actually 3 days,  you only have to be competent to work on a boat that is not residential.. I havent got a problem with that, how do you determine competence ?

 

All the aircraft or ships I worked on have been retired. Some times it is worth a refresh.

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1 minute ago, WotEver said:

It’s generally derived from pertinent experience. That plus extensive learning from folks who know their craft. 

Which is why to do it properly takes years and years, especially in industries like the inland marine industry that almost totally consists of one offs and owner modified boats.

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49 minutes ago, Tony Brooks said:

Which is why to do it properly takes years and years, especially in industries like the inland marine industry that almost totally consists of one offs and owner modified boats.

I will never disagree with that, how many youngsters are coming into the inland marine industry ?

 

Under 55, I consider myself a youngster. it maybe an area thing.

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2 hours ago, Alan de Enfield said:

Be careful - he has a sestificate that says he can connect wires to battery terminals !!!!!

 

Have you got one ?

I've got 24.

There are 2 on each cell and I have 12 Li cells.

There are also terminals on the LA's but I have run out of toes and fingers and Mrs Bob would only lend me four.

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6 hours ago, Dr Bob said:

 My bote does not get that hot.

 

6 hours ago, Alan de Enfield said:

 

Have you got one ?

Of course he has. Pay attention. It is named Keith Harris!

 

ETA. Its a Orville name.

Edited by rusty69
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On 10/01/2020 at 10:24, Dr Bob said:

 

Some peeps post some very bad advice on here. A waste of money mixing LAs with LiFePO4s? Nah. Excellent cost benefit. I would love to hear Pompey's experience to back up his statement.

 

In response to Stationmasters OP, I think what I have done is pretty near to what he is wanting. The outline of my system was in this thread (page 9, post 212) although there have been some changes since posting.

 

The more upto date system was described in January's 2020 edition of Canal Boat Magazine. What I did was to bolt on 480Ahrs of LiFePO4 capacity in parallel to my 660Ahr LA bank. When I bought the 12 LiFePO4 cells I wasnt sure they would be compatible with the alternator charging and didnt want to disrupt the existing battery system and charging, so I just connected them up together with a big isolation switch between the two banks. The system has now been in use for 10 months. I run it between 12.8V and 13.2V on discharge so the LA bank is always at least 95% full. That means the Li bank always has the capacity to take whatever is thrown at it and could do SM's job of taking power from the TP etc. The benefit of leaving the LA's in place is that when I leave the boat, or one of our sprogs want a week out in it, I can isolate the Li's and let them use it just on the LA's. If we sell the boat I will just unbolt the wires and take the Li's with me.

I am now totally reliant on the LiFePO4s but have the option to switch back to LA's. I will never go back to LA's only. In time as the LA's die (no sign yet) I will take them out of circuit.

 

The system was put together using off the shelf stuff and was simple to do once I had got my head around making 50mm battery connections. Total cost was around £1250 but this could be reduced by going for just 240Ahr or 360Ahr Li cells. Even at £1250 this will pay back for itself in 5  years with much, much reduced engine running (cost of diesel only). Factor in engine hours, servicing and noise reduction and the benefits get much better.

 

The OP shouldnt be frightened of looking at a hybrid system like this if he understands the need to learn about lithium voltages and charging and be prepared to spend a bit of time monitoring in the first few months of operation.

I apologise, for 'Lithium burns with no air', comment, it does, however water increases the' rapid destruction' of a Lithium based battery, LiFePO4's have been attributed to fires, the main cause that I can see is excessive damage. IIRC, if a Lithium based battery has its separator compromised it will either go into 'thermal runaway', or 'rapid destruction'.

 

If using Cells from a write off electric vehicle, how electrically safe would they be, especially on a boat?

 

A lot of good advice on here. I haven't read it all, and I haven't learnt all the all the lessons that life has to give. 

 

 

 

 

 

 

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