At 60 posts in I’d call it a slow burner (no batteries were harmed in the writing of this post).
Ian
How difficult is to add a Lithium battery?
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At 60 posts in I’d call it a slow burner (no batteries were harmed in the writing of this post).
Ian
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Firstly, I’d like to thank gus-lopez for the inspiration.
That’s certainly not the case in the narrowboat world. There, the hybrid bank (entirely separate from the engine battery) uses no B2B; the LiFePO4 battery and the lead acid battery are both connected directly to the alternator.
The B2B will certainly fulfill that role provided that the current is limited to a level that is appropriate to the alternator; if not, the alternator would still overheat.
Not necessarily, there’s more than one way to limit the current being drawn from the alternator. One, simple, first principles, method is to add resistance to the charge path. This can be achieved by increasing the length of the alternator cable (thereby adding resistance); problem solved.
Wise move! Clearly, you had no/insufficient means of limiting the current draw - see above.
If you’re referring to the Victron video, that has been debunked many times. It was an unrealistic test designed to destroy the alternator.
Indeed.
It is why they charge more quickly, irrespective of the charge source.
that rather depends on which boats you compare them with.
A spilt charge system simply connects the starter and leisure batteries together when the engine is running. And, yes, usually, as soon as LiFePO4 batteries are used as the leisure bank a B2B is fitted to:
- provide an appropriate charge profile
- limit the current drawn
- protect against a BMS disconnect spike that would damage the alternator (this function is performed by the lead acid battery in a hybrid bank)
No, you are not describing a hybrid bank, you are describing a conventional LiFePO4 installation.
It protects against a voltage spike not excess current.
There is no voltage spike/excess current when a B2B is fitted.
Without suitable protection, that is a risk.
The LiFePO4 will also supply the large loads.
Indeed it does.
No, because of its lower internal resistance, the LiFePO4 battery charges first (and quickly).
Indeed it does.
It’s ideal for all loads and is indeed perfectly happy to sit in a partial SoC.
Indeed it does.
Indeed it does but not because it charges preferentially but because the LiFePO4 charges preferentially and whose voltage rises to a level that will allow a trickle charge through to the lead acid battery. Once the LiFePO4 is fully charged the lead acid will complete its charge cycle.
Well, he is wrong then.
AI (and Google) are wonderful resources but they are often inaccurate.
As I said earlier, not in the narrowboat world it isn’t.
Ian
Apologies as I don't know how to quote/respond to individual segments of text.
To be honest I'm not sure its really necessary anyway, and it would bore everyone to tears.
I can say that I disagree with a few of your comments.
E.g. on the point about whether the term 'hybrid' can include the use of B2Bs, I'm going to stick with the information from Google AI and my BSS inspector.
I think some other comments added useful detail (that I personally was already aware of), but did not contradict points I raised (e.g. the comment that a B2B would only help keep the alternator cool if it was rated at the appropriate current, which I think is kind of implied during my earlier posts).
Unfortunately it isnt usually appropriate or required to give full and detailed explanations and qualifications to all of one's comments, or we would spend all day writing these things.
I could have added more detail about the 'long wire' method of adding resistance in order to manage current, but again my thoughts was that it was just too much detail. But thanks for the clarifications.
Your comment about the the burning alternator is moot really, in my view. Clearly an alternator that is running at over 125 degrees (and rising fast) is going to suffer damage if that situation continues for a significant length of time. My own experience was that two of my alternators died after only 4 years charging via B2Bs, both running at about 80 degrees.
My point is that the alternator doesnt have to actually catch fire for overworking it to be a bad idea.
Thanks also for the clarification about not needing a Sterling alternator protector if I have a B2B, that is really helpful.
Can I also get rid of the lead acid battery from that charging setup, and just connect directly from alternator to the B2B charger?
PS - one thing I am curious about though, since you took the trouble to mention it at the top of your post - what was the nature of the inspiration provided to you by Mr Lopez?
MichaelT
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Blimey you been taking quote lessons off Gus LopezFirstly, I’d like to thank gus-lopez for the inspiration.
That’s certainly not the case in the narrowboat world. There, the hybrid bank (entirely separate from the engine battery) uses no B2B; the LiFePO4 battery and the lead acid battery are both connected directly to the alternator.
The B2B will certainly fulfill that role provided that the current is limited to a level that is appropriate to the alternator; if not, the alternator would still overheat.
Not necessarily, there’s more than one way to limit the current being drawn from the alternator. One, simple, first principles, method is to add resistance to the charge path. This can be achieved by increasing the length of the alternator cable (thereby adding resistance); problem solved.
Wise move! Clearly, you had no/insufficient means of limiting the current draw - see above.
If you’re referring to the Victron video, that has been debunked many times. It was an unrealistic test designed to destroy the alternator.
Indeed.
It is why they charge more quickly, irrespective of the charge source.
that rather depends on which boats you compare them with.
A spilt charge system simply connects the starter and leisure batteries together when the engine is running. And, yes, usually, as soon as LiFePO4 batteries are used as the leisure bank a B2B is fitted to:
- provide an appropriate charge profile
- limit the current drawn
- protect against a BMS disconnect spike that would damage the alternator (this function is performed by the lead acid battery in a hybrid bank)
No, you are not describing a hybrid bank, you are describing a conventional LiFePO4 installation.
It protects against a voltage spike not excess current.
There is no voltage spike/excess current when a B2B is fitted.
Without suitable protection, that is a risk.
The LiFePO4 will also supply the large loads.
Indeed it does.
No, because of its lower internal resistance, the LiFePO4 battery charges first (and quickly).
Indeed it does.
It’s ideal for all loads and is indeed perfectly happy to sit in a partial SoC.
Indeed it does.
Indeed it does but not because it charges preferentially but because the LiFePO4 charges preferentially and whose voltage rises to a level that will allow a trickle charge through to the lead acid battery. Once the LiFePO4 is fully charged the lead acid will complete its charge cycle.
Well, he is wrong then.
AI (and Google) are wonderful resources but they are often inaccurate.
As I said earlier, not in the narrowboat world it isn’t.
Ian
If you have a lead acid leisure battery connected directly in parallel with your LiFePO4 battery then it is not required if you use a B2B.
Ian
PS I think that we have drifted this thread much too far already.
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We have drifted it, but no so much that I cant add a thank you for that helpful information.
I've mentioned this a couple of times during discussions on the Canal World Discussion Forum, but I wasnt able to get a conclusion that I had full confidence in.
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That google AI crap will have people believe anything these days, it was bad enough just google but jeeps AI puts anything up.yup, google is always right, isn't it
I've been running a Lead/Lithium mix for over 4 years now, and I have supplied a special controller of my own design to optimize the combination to people virtually all over the world for their own Hybrid setups.
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Must be the Fogstar drift pro for how far threads drift lolFogstar Drift?
Mike.
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Firstly, I’d like to thank gus-lopez for the inspiration.
That’s certainly not the case in the narrowboat world. There, the hybrid bank (entirely separate from the engine battery) uses no B2B; the LiFePO4 battery and the lead acid battery are both connected directly to the alternator.
The B2B will certainly fulfill that role provided that the current is limited to a level that is appropriate to the alternator; if not, the alternator would still overheat.
Not necessarily, there’s more than one way to limit the current being drawn from the alternator. One, simple, first principles, method is to add resistance to the charge path. This can be achieved by increasing the length of the alternator cable (thereby adding resistance); problem solved.
Wise move! Clearly, you had no/insufficient means of limiting the current draw - see above.
If you’re referring to the Victron video, that has been debunked many times. It was an unrealistic test designed to destroy the alternator.
Indeed.
It is why they charge more quickly, irrespective of the charge source.
that rather depends on which boats you compare them with.
A spilt charge system simply connects the starter and leisure batteries together when the engine is running. And, yes, usually, as soon as LiFePO4 batteries are used as the leisure bank a B2B is fitted to:
- provide an appropriate charge profile
- limit the current drawn
- protect against a BMS disconnect spike that would damage the alternator (this function is performed by the lead acid battery in a hybrid bank)
No, you are not describing a hybrid bank, you are describing a conventional LiFePO4 installation.
It protects against a voltage spike not excess current.
There is no voltage spike/excess current when a B2B is fitted.
Without suitable protection, that is a risk.
The LiFePO4 will also supply the large loads.
Indeed it does.
No, because of its lower internal resistance, the LiFePO4 battery charges first (and quickly).
Indeed it does.
It’s ideal for all loads and is indeed perfectly happy to sit in a partial SoC.
Indeed it does.
Indeed it does but not because it charges preferentially but because the LiFePO4 charges preferentially and whose voltage rises to a level that will allow a trickle charge through to the lead acid battery. Once the LiFePO4 is fully charged the lead acid will complete its charge cycle.
Well, he is wrong then.
AI (and Google) are wonderful resources but they are often inaccurate.
As I said earlier, not in the narrowboat world it isn’t.
Ian
That is a pretty good summary of how an actual Lead/Lithium Hybrid setup works
I think we have had a few discussions in the past and while we don't really see eye-to-eye on the methodology of using cable as a current-limiting device, clearly we agree on how a Hybrid system works in practice and useage
Totally off-topic for the thread of course, but, IMO, a Hybrid system can often be superior to both a 100% Lead system AND a 100% Lithium system (and of course, in the narrowboat world, the weight of Lead Batteries is not an issue but in fact a benefit as they can replace brick ballast for something that actually has an extra useful purpose
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You need a Battery at the 'alternator end' if you are using a B2B Charger. If you got rid of the Battery, then you would need to change your B2B to an A2B - An Alternator to Battery Charger
And yes, there is such a thing. I think the most common one in made by Sterling Power, is not very good by all accounts AND is pretty expensive compared to a comparable B2B. As far as I can tell, most folk with boats who install Lithium (or add Lithium or their 'house' Lead to make a Hybrid Bank) and wish to be able to limit the current load on their dedicated house alternator will actually introduce a Lead Acid battery at the alternator end in order to be able to use a B2B rather than having to get an A2B.
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You need a Battery at the 'alternator end' if you are using a B2B Charger. If you got rid of the Battery, then you would need to change your B2B to an A2B - An Alternator to Battery Charger
And yes, there is such a thing. I think the most common one in made by Sterling Power, is not very good by all accounts AND is pretty expensive compared to a comparable B2B. As far as I can tell, most folk with boats who install Lithium (or add Lithium or their 'house' Lead to make a Hybrid Bank) and wish to be able to limit the current load on their dedicated house alternator will actually introduce a Lead Acid battery at the alternator end in order to be able to use a B2B rather than having to get an A2B.
Thanks very much for that clarification.
My boat had one of those Sterling A2B chargers when I first got it 5 years ago. But when I replaced the lead acid leisure batteries with lithiums, I immediately realised that the A2B was not controlling the charging current put out by the alternators, and both alternators were starting to overheat. I tried a few different charging profiles (it didnt have a lithium profile as I recall), but I couldnt figure out a way to reduce the charging current using the A2B.
It was very disappointing, because an 'expert' friend had told me that I could simply swap in the lithiums and it would all work.
So I did a few experiments using a long length of wire to reduce the charging current (it was 10mm square I think). It did work (once I determined the correct length and width of cable), but it seem to get a bit hot, and tbh I didnt feel 100% comfortable with this length of cable hanging around in the engine bay.
I then tried installing a single Sterling B2B (with a lead acid in parallel with the lithiums), and that seemed to work better - and it looked a lot neater than 7 metres of cable. That said, I know a few boaters who have been use the 'long wire' method for a few years with no problem at all.
I would guess that most of the installations in the last few years (that I've spoken to anyway) have tended to use B2Bs of one sort or another. I tried a single Sterling B2B at first, and then another one. But I didnt like them, and I've ended up with Victrons.
About 6 months after the initial install I realised that my lithium batteries did not have built in BMS systems that would disconnect them in case a their voltage getting very high, or indeed very low. They were ex-EV batteries (Valence), and they needed an expensive external module to manage their high and low voltage disconnection functions.
So for me, installing lithium batteries was quite a journey, and not as cheap as I hoped it would be.
But five years ago lithiums were not very common on boats, and not many of the marine electricians knew how to work with them, so it wasnt that easy to get well-informed expert support.
But the lithiums perform so much better and in so many ways (in my view anyway), that I just couldn't go back to lead acids now, unless I was truly desperate.
I dont know how/where I'm going to fit a 460Ah Fogstar in my chosen campervan (I think it will be a Wildax Constellation 3XL), but I'll be spamming questions about it on this forum when the time comes, hopefully early next year, but depends on a house sale.
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All this talk of B2B's. If you don't have a smart alternator, do you need one?
MichaelT
LIFE MEMBER
We didn't on our last van and no problem. OK maybe not ideal with less output but it all worked with just changing the solar controller to lithium and mains charger to gel.
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It depends on whether you need to limit the current draw and that depends on the wiring on your van.
The risk if you don’t fit one is that you over stress your alternator (potentially damaging it) and/or overheat your wiring (with the attendant fire risk).
But you might not need one.
I hope that helps.
Ian
MichaelT
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I don't get the overstress alternator bit. If your set up say outputs 20a whatever battery you have it won't give more but if I fit a B2B at 50a it surely puts more stress on the alternator. Whatever you have it's the same alternator doing the work a B2B doesn't change that.
I know lithium can draw much more than a lead acid and wiring etc should be checked but I just dropped a lithium in made the changes and got up to about 20a going in the same as a lead acid.
If you have no means of limiting the current drawn by a LiFePO4 battery, the alternator will get stressed.
The output available depends on two things:
- The demand from the load
- The maximum output capability of the supply
The more current you demand the harder the alternator will work. Some B2Bs have the ability to limit the current drawn. But, remember, this discussion is related to the potential impact of NOT fitting a B2B.
No, but compared with not fitting a B2B the alternator may be trying to deliver its max output.
Indeed it should.
You must just be lucky then I guess.
Ian
MichaelT
LIFE MEMBER
Nope informed decision, all scared mongering IMHO. But based on the van I had and equipment fitted and talking to the battery maker.If you have no means of limiting the current drawn by a LiFePO4 battery, the alternator will get stressed.
The output available depends on two things:
If you connect a LiFePO4 without a B2B connected then you may be asking for more than the alternator can sustain.
- The demand from the load
- The maximum output capability of the supply
The more current you demand the harder the alternator will work. Some B2Bs have the ability to limit the current drawn. But, remember, this discussion is related to the potential impact of NOT fitting a B2B.
No, but compared with not fitting a B2B the alternator may be trying to deliver its max output.
Indeed it should.
You must just be lucky then I guess.
Ian
Great stuff.
Your initial response suggested a much more casual approach than the considered approach you describe above.
Ian
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MichaelT
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I wanted to try it as B2B were more expensive then but it all worked so no need to change.Great stuff.
Your initial response suggested a much more casual approach than the considered approach you describe above.
Ian
Coolcats
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Its not hard Dethleffs are doing the same as Hymer and utilising the BOS LE 300 in this link
it means you keep a GEL and add lithium its a straight add in no mess no fuss, not the cheapest but then again your dont have to change anything else so probably works out similar
Alternately add the BOS S which can be used in either Hybrid (with a GEL) or stand alone again nothing to change
It is entirely doable if there is sufficient resistance in the charge path. The ‘long lead’ method (used by narrow boaters) that I have discussed elsewhere is used simply to add resistance into the charge path. However, it is important to understand the issues associated with this approach in order that you can put necessary mitigations in place in the event that operating envelopes are challenged.
You have, effectively, a hybrid battery bank whereby your engine battery is connected in parallel with your LiFePO4 leisure bank. Having your engine battery in parallel (via the split charge relay) with your LiFePO4 battery provides spike protection for your alternator in the event that the BMS disconnects the charge source when the OVP (over voltage protection) activates.
Ian
MichaelT
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It all went thru the EBL.
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MichaelT
LIFE MEMBER
Yes I think it was and it was for 2 AGM batteries.
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The EBL will limit the charge to usually 18A, so adding Lithium will not create an issue on alternator overload.
However, a major benefit of Lithium (possible THE key benefit) is the ability to charge the batteries faster, so by keeping with the EBL is, IMO , a flawed decision. But each to their own.
However, a major benefit of Lithium (possible THE key benefit) is the ability to charge the batteries faster, so by keeping with the EBL is, IMO , a flawed decision. But each to their own.
MichaelT
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Why pay 500 or so for something I didnt need. Never ran out of power in 4 years and never used a mains charger.
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That is how it is designed. if you want more info, I suppose speak to Schaudt/Lippert?
I am guessing you think the EBL just contains a relay that flips with a D+ signal? It has a, albeit pretty basic, B2B charger internally
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