Lithium Ion Leisure batteries. (1 Viewer)

Feb 27, 2011
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I have looked at these before and was put off by cost and fire risk but I have recently started looking at them again.

The advantages are;
They charge at a constant rate. When you charge a lead acid battery the bulk stage is fine but when it gets to the absorption stage your solar panels output current is not totally used and is therefore wasted. When you charge a lead acid battery it is at best 85% efficient a lithium battery is 99%. So you get more out of your solar panels.

A lead acid battery needs to be regularly fully charged to maintain its capacity. A lithium based battery can run between 50%-95% and anything in between without needing a full charge.

A lithium battery happily works on a depth of discharge down to 85% whereas a lead acid battery only gives 50%. So a 100AH lead acid is effectively only a 50AH battery a 100AH Lithium based battery is 85AH.

A lithium based battery is less than half the weight usually for it's rated capacity . So you can either have twice as many for the same weight or have less weight for the same capacity. Please see previous paragraph though.

A lithium battery doesn't suffer from Peukert’s losses. So if you pull a large current for an inverter you don't lose the capacity of the battery like you do with lead acid.

A lithium based battery appears to have a lifespan in excess of twice the number of cycles of a lead acid battery if not more.

Finally the fast charge rate. If you have charger capable you can fully charge a Lithium battery in half an hour and the charge rate doesn't slow down.

ok. The downsides are they cost a bleeding fortune which is where this post comes in.
I have been looking at a lot of youtube videos where people have been using 18650 batteries to make battery packs for their e-bikes. I am now looking into doing the same using batteries from recovered laptop batteries.

I am aware of the need for BMS and specialised charger etc etc.

I am just wondering if anyone else on here has done anything similar before. Also thought it might make an interesting thread for people who are interested in the techy stuff.

@Techno I don't know why you but your name popped to mind :p
 
Last edited:
OP
OP
Gromett
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There are quite a few videos on youtube. but this guy has done a series. This one is worth a watch.


He creates a battery bank to power his VW camper van using recovered laptop batteries..
 
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Gromett
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I am looking at building lot of small packs of 20 batteries in each using a pair of these for each one.

Broken Link Removed

20 batteries at 2Ah (2,000mAh) gives 40AH at 3.7 V. I would need 3 or 4 of these packs in series to give me the 12V. I am still trying to figure out if I need 3 x 4.2V or 4 x 3.7v depending on whether you measure the nominal voltage or max voltage. Research on going.

But if I use 4 that will be 40AH a pack and require 80 batteries. I am looking at paying no more than 50p a battery so total cost £40.

A 100AH lead acid will cost me about £100 but will only give me 50AH. so that is £2/AH of usable. If I can get the used Lipo batteries at 50p each and get 80% usable capacity I am looking at about £1.20/AH usable.

Check my maths someone please :p

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Snowbird

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I converted 2 mobilty scooters from lithium batteries to SLA. I have 3 Lithium chargers here if they are any good to you. The downside is they are 24 volt, but are freebies.
 
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Gromett
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I converted 2 mobilty scooters from lithium batteries to SLA. I have 3 Lithium chargers here if they are any good to you. The downside is they are 24 volt, but are freebies.

I will be doing these at 12V. I already have an expensive 50A sterling charger which has profiles for Li batteries. Thanks for the kind offer though (y)

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Snowbird

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Save me one of them Dave (y) No Idea what I will do with it yet but if it's for free I will figure something out
terry

They are yours pal. Am having a clearout whilst am home.
 

Techno

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I have looked at these before and was put off by cost and fire risk but I have recently started looking at them again.

The advantages are;
They charge at a constant rate. When you charge a lead acid battery the bulk stage is fine but when it gets to the absorption stage your solar panels output current is not totally used and is therefore wasted. When you charge a lead acid battery it is at best 85% efficient a lithium battery is 99%. So you get more out of your solar panels.

A lead acid battery needs to be regularly fully charged to maintain its capacity. A lithium based battery can run between 50%-95% and anything in between without needing a full charge.

A lithium battery happily works on a depth of discharge down to 85% whereas a lead acid battery only gives 50%. So a 100AH lead acid is effectively only a 50AH battery a 100AH Lithium based battery is 85AH.

A lithium based battery is less than half the weight usually for it's rated capacity . So you can either have twice as many for the same weight or have less weight for the same capacity. Please see previous paragraph though.

A lithium battery doesn't suffer from Peukert’s losses. So if you pull a large current for an inverter you don't lose the capacity of the battery like you do with lead acid.

A lithium based battery appears to have a lifespan in excess of twice the number of cycles of a lead acid battery if not more.

Finally the fast charge rate. If you have charger capable you can fully charge a Lithium battery in half an hour and the charge rate doesn't slow down.

ok. The downsides are they cost a bleeding fortune which is where this post comes in.
I have been looking at a lot of youtube videos where people have been using 18650 batteries to make battery packs for their e-bikes. I am now looking into doing the same using batteries from recovered laptop batteries.

I am aware of the need for BMS and specialised charger etc etc.

I am just wondering if anyone else on here has done anything similar before. Also thought it might make an interesting thread for people who are interested in the techy stuff.

@Techno I don't know why you but your name popped to mind :p

Lithium is only held back by the price. Leisure batteries are best thought of as best bang for buck.
I'm using Lithium Polymer batteries in my Lego models but a 7.4volt battery weighs a few grams and costs £42.99 :ROFLMAO:
 
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Gromett
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Lithium is only held back by the price. Leisure batteries are best thought of as best bang for buck.
I'm using Lithium Polymer batteries in my Lego models but a 7.4volt battery weighs a few grams and costs £42.99 :ROFLMAO:

I am looking at using recovered cells from laptop batteries. I have 3 bids on ebay for job lots at the moment. Currently the bids are at < 20p a cell.
I need 80 Cells to make a 40AH battery in 4s20p format. At current bids this would be £16.... I doubt I will get all my packs that cheap but I should get a couple.
Even at my upper limit of 50p that still works out £40 if my maths is correct?

There are loads of these batteries coming to market now and every single youtube video I have seen has had the vast majority of cells still giving between 2.2 and 2.4 AH of remaining life. I am basing my calcs on only getting 2AH per cell.

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Nov 30, 2009
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The downsides are they cost a bleeding fortune which is where this post comes in.

Your not Joking......BROKEN LINK

They do tick all the boxes though ;)
 

Lee Fryer

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I don't think hobby king will do batteries that resemble a Lego product in any way shape or form BUT stand to be corrected (y)
Sorry thought they would hidden in battery box.
Lee

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Steve

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As you know lipo cells are 3.7v so x4 = 14.8v. may be a little high for a 12v system. And lipo cells keep a steady voltage for nearly all their capacity. Unlike a Lead Acid. I have quite a few lipos of various cell sizes which I use on my rc trucks. When you start mixing cells things can go wrong with a bang and a nice fire (done that) There are lipo 12v car type batteries on the market but the price is still high. But it’s the BM side that will really cost. I have had a play around with some of the bits I have and the charger I have needs a pc to run it. You only need a cell to have the wrong resistance and things get hot very quick. Please be careful and NEVER leave them charging unattended. But its good fun being a kid again.:)

Steve

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Techno

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Looks like that might contain 2 x 18650 batteries? When you get a knackered one it might be worth opening to see what is inside?
From the weight I think its empty :LOL:

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Techno

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For Lego to embark on LiPo batteries where children are involved is quite a bold move so their product must be pretty well tested.
 

Terry

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Hi Karl check these out
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THERE ARE LOADS MORE AT SIMILAR PRICES is it worth going down the second hand route -plus Like @Steve SAYS @3.7 V MUTIPLES OF 4 WOULD GIVE YOU 14.8V?????
That may give/make a good jump starter pack or would that be to much ?I am sure both Steve and Andy @Techno will be along to advise (y):D
terry
 

Steve

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They do make great boaster power packs as they can discharge very quickly. But as Ralph-n-Bev said you can get voltage droppers but good ones arnt cheap. I have used a 4 cell 14v 10amp to start my freelander. it is marked up as discharging at 50c which beens 50x its capacity. so 500amps from some thing the size os a beer can!!!!!!!

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TheBig1

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its going to be a fair few years until lithium leisure batteries are more cost effective. just this afternoon i ordered 2 new batteries for our van. 2 lead calcium batteries rated at 225ah for £330 delivered. the lead calcium batteries are rated for double the recharge cycles of standard lead acid, so are very cost effective. the equivalent lithium battery bank would be more like £3500 so ten times the cost

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OP
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Gromett
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I ended up putting this project on the back burner. I bid on 10+ different bulk packs of batteries and all of them went over my price limit. I wasn't prepared to spend £100's for an experiment/test.

Once they come down in price further I will look at it again.
 
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Gromett
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One of the youtube channels I follow has just bought a bunch of second hand Tesla battery modules and what he is doing with them is amazing.
He said he buys off ebay and on ebay.com there are loads of them for sale. I didn't think there would be any on the UK ebay.co.uk but.....


That is £900 for a 500AH lithium Ion battery which is close to equivalent to a 1,000Ah Lead acid battery. The advert states it is 250AH at 24V if you convert this to 12V you half the voltage but double the AH. A lead acid battery shouldn't be discharged to below 50% whereas a Li-Ion can be discharged practically all the way.

At this price it is very competitive with Lead Acid and has loads of advantages....

By my maths it weighs about 34KG in comparison to my old 1,000Ah battery bank which weighed in at 300KG...

So tempted to save up and take a trip to Belgium... Maybe a project for next year once I get all my welding sorted and the trailer fully kitted out....
 
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Robert Clark

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One of the youtube channels I follow has just bought a bunch of second hand Tesla battery modules and what he is doing with them is amazing.
He said he buys off ebay and on ebay.com there are loads of them for sale. I didn't think there would be any on the UK ebay.co.uk but.....


That is £900 for a 500AH lithium Ion battery which is close to equivalent to a 1,000Ah Lead acid battery. The advert states it is 250AH at 24V if you convert this to 12V you half the voltage but double the AH. A lead acid battery shouldn't be discharged to below 50% whereas a Li-Ion can be discharged practically all the way.

At this price it is very competitive with Lead Acid and has loads of advantages....

By my maths it weighs about 34KG in comparison to my old 1,000Ah battery bank which weighed in at 300KG...

So tempted to save up and take a trip to Belgium... Maybe a project for next year once I get all my welding sorted and the trailer fully kitted out....

Did you see these ?

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