The end of lead acid batteries

[Dave_P]

A typical 110ah cheap leisure battery might cost £70. That's roughly 60p per amp hour.

 

I've just bought this: https://www.amazon.co.uk/dp/B00F5Q4F0U/ref=pe_1909131_77697001_tnp_email_TE_AMZLdp_1

 

It's a 22ah li-ion battery which I can use as a back up for phone/tablet/mifi charging. I got it on a deal for £12.99. The usual price is £19.99.

 

That's 90p per ah usually or 59p per ah for me.

 

Other benefits is that it will discharge down to 0% and has its own outputs 3xUSB.

 

It outputs at 5v but how long before someone sells a cheap, scaled up version of this which outputs at 12v and can run all your boat electrics.

 

Or am I missing something obvious?

[frangar]

Just like most things you tend to get what you pay for.

 

In my experience with "cheap" li ion batteries they don't last nearly as long as the originally supplied units either in capacity or life expectancy.

 

Cheers

 

Gareth

[DaveP]

It's getting there, but. Better to compare the Wh cost rather than the Ah since they're differing voltages - its still 2.4x (usually 4x) the lead-acid cost. And, I presume, it doesn't come with the gubbins to charge from an alternator. The time is coming though, I fully expect the next time I replace my leisure batteries in a few years to have to weigh up the alternatives more closely. (And I'd say that 110ah lead-acids are 55-60ish rather than 70).

[nicknorman]

Don't forget that an AH rating in itself is pretty meaningless, you have to take into account the voltage as well. Of course normally we expect 12v in which case looking at the AH is fine. But otherwise one should look at the WH (watt hours). The battery you link to looks like it is around 5v so stores less than half the energy of a 12v battery rated at the same AH.

 

Another issue is that charging has to be very precisely controlled, you typically need a charging connection to each cell to ensure equalisation without overcharging the other cells

 

Anyway, Li-Ion cells do have a lot of potential but I think there is a way to,go before we see them in regular use on boats due to the cost. One of the advantages is low weight which isn't much of an advantage on a narrowboat.

[Guest]

Don't forget that an AH rating in itself is pretty meaningless, you have to take into account the voltage as well. Of course normally we expect 12v in which case looking at the AH is fine. But otherwise one should look at the WH (watt hours). The battery you link to looks like it is around 5v so stores less than half the energy of a 12v battery rated at the same AH.

Another issue is that charging has to be very precisely controlled, you typically need a charging connection to each cell to ensure equalisation without overcharging the other cells

Anyway, Li-Ion cells do have a lot of potential but I think there is a way to,go before we see them in regular use on boats due to the cost. One of the advantages is low weight which isn't much of an advantage on a narrowboat.

Leisure batteries of course are not just for Narrowboats and the low weight factor would be a big advantage in caravan applications.

[nicknorman]

Leisure batteries of course are not just for Narrowboats and the low weight factor would be a big advantage in caravan applications.

Not mine, I doubt it will move again! But yes you are right, on the other hand this is a boaty forum. As an aside having experienced caravan leisure batteries for a while (they don't seem to last long when you are "off grid") I'm planning to get a pair of Trojans for my new caravan.

[Guest]

Not mine, I doubt it will move again! But yes you are right, on the other hand this is a boaty forum. As an aside having experienced caravan leisure batteries for a while (they don't seem to last long when you are "off grid") I'm planning to get a pair of Trojans for my new caravan.

No you won't get much out of them. or rather it. Modern 'vans are really set up primarily for regular 'on grid' connection. We have a small solar panel on the roof but that really is just to keep a trickle going in while in storage and to keep on top of the demands of the alarm.

 

i suppose the only real advantage in boats of a lighter set up comes at installation time and the potential to avoid having to trim a boat taking account of the weight. Ours had a quite noticeable list with no batteries on board.

[mrsmelly]

Not mine, I doubt it will move again! But yes you are right, on the other hand this is a boaty forum. As an aside having experienced caravan leisure batteries for a while (they don't seem to last long when you are "off grid") I'm planning to get a pair of Trojans for my new caravan.

 

Cecil and Eric?

 

Tim

[Dave_P]

I've definitely seen the prices for these li-ion batteries tumbling in the last couple of years. If the electrical bods on here are saying that the real cost of li-ion is around 2x lead acid due to 5v against 12v then look at factoring in the maximum rate of discharge and it's a very close call IMO. Does anyone currently manufacture a 12v li-ion battery which can be charged from an alternator?

 

If there isn't one now, I predict that an off-the-shelf product will be available in the next couple of years.

 

I know there's the Tesla power wall but that's I different thing really. I'm thinking of a 100ah battery which retails for around £100-£150 pounds.

[nicknorman]

http://www.mastervolt.com/products/li-ion/mli-ultra-12-2500/

Around £2000

 

Victron do something similar, around £1000 per 100AH

Edited March 22, 2016 by nicknorman

[MtB]

Does anyone currently manufacture a 12v li-ion battery which can be charged from an alternator?

 

 

 

Wouldn't a better question be "Does anyone currently manufacture an alternator capable of charging Li Ion batteries?"

 

How do you charge your 5v Li Ion battery Dave?

[Guest]

OK I'll ask.

 

What differences are there between charging the two types?

[Giant]

It would be quite straightforward to build an aftermarket alternator regulator that would allow charging lithium ion batteries from a standard alternator.

 

It would need to be connected to a shunt, so it can do the constant current phase of the charge, and would need balancing connections to the midpoint connections between cells, as well as temperature sensors to be safe. But none of that is particularly difficult.

[MtB]

OK I'll ask.

 

What differences are there between charging the two types?

 

 

See Nick's post No 4

 

Another issue is that charging has to be very precisely controlled, you typically need a charging connection to each cell to ensure equalisation without overcharging the other cells

[Loafer]

Each cell in a LiPo battery needs its own charge supply. Otherwise it is impossible to charge correctly and one cell is likely to overcharge while the rest are catching up. This ensures each cell is charged and discharged correctly.

 

Misuse ends in tears!

[WotEver]

Misuse ends in tears!

... and the release of copious amounts of magic smoke plus impressively high temperatures.

[Guest]

See Nick's post No 4

 

Another issue is that charging has to be very precisely controlled, you typically need a charging connection to each cell to ensure equalisation without overcharging the other cells

Missed it cheers. Surely that is possible to achieve relatively cheaply? - we have after all put a man on the moon..

[MtB]

It would be quite straightforward to build an aftermarket alternator regulator that would allow charging lithium ion batteries from a standard alternator.

 

It would need to be connected to a shunt, so it can do the constant current phase of the charge, and would need balancing connections to the midpoint connections between cells, as well as temperature sensors to be safe. But none of that is particularly difficult.

 

 

Yes but no-one has done it yet, and brought it to market.

 

Further, I suspect batteries and alternators would need to be sold as matched pairs.

Missed it cheers. Surely that is possible to achieve relatively cheaply? - we have after all put a man on the moon..

 

 

Cheap once the economies of scale kick in.

 

How much did the Apollo program cost, by the way?

[RLWP]

Or am I missing something obvious?

 

You may remember the aeroplane fires a coupe of years ago from Li-Po batteries. Laying aside the fires, it shows that large capacity batteries are already out there

 

Richard

[nicknorman]

Missed it cheers. Surely that is possible to achieve relatively cheaply? - we have after all put a man on the moon..

It is much more sensible to put all that in the battery, not in the alternator. Otherwise you would have to have a different alternator for each type and number of batteries. This is what is in the Victron and Mastervolt offering I linked to.

 

I suspect part of the cost issue is the degree of take up, ie low manufacturing volume. Which is not too surprising considering the price. Vicious circle! But I'm sure they will come down, and soon you'll probably be able to buy Chinese ones, that may double as boat heaters.

[Guest]

How much did the Apollo program cost, by the way?

No idea - but I know my phone has more computing power than was on that spacecraft and it didn't cost anywhere near as much....

[PaulG]

Each cell in a LiPo battery needs its own charge supply. Otherwise it is impossible to charge correctly and one cell is likely to overcharge while the rest are catching up. This ensures each cell is charged and discharged correctly.

 

Misuse ends in tears!

It probably would end in tears.

IMHO, LIPOs are a definite no-no for boats.

They should never be charged unattended.and should ideally be placed in a fireproof container while charging.

Discharge below a certain voltage (from memory around 3v per cell) kills them permanently.

[nicknorman]

It probably would end in tears.

IMHO, LIPOs are a definite no-no for boats.

They should never be charged unattended.and should ideally be placed in a fireproof container while charging.

Discharge below a certain voltage (from memory around 3v per cell) kills them permanently.

However all that should be handled by the internal electronics. We are not talking about raw cells here, but a package that includes charging control and cuts the output off when the cells get to their minimum SoC.

[MartinC]

For those who are interested in the current state of research http://journals.cambridge.org/download.php?file=%2FMRS%2FMRS39_12%2FS0883769414002851a.pdf&code=b2a525ca6ec883f7ff41ae708a1ef5e1

[Dave_P]

 

 

Wouldn't a better question be "Does anyone currently manufacture an alternator capable of charging Li Ion batteries?"

 

How do you charge your 5v Li Ion battery Dave?

I charge it whenever I'm somewhere with mains leccy. Work mostly.