Battery tech

[clissold345]

Thanks for the link. I've simplified the data (page 24) slightly but hopefully Ive not made mistakes.

Levelised estimates of costs of electricity generation for projects commissioning in 2025, in real 2021 prices:

- Gas £114/MWH
- Offshore wind £44/MWH
- Onshore wind £38/MWH
- Large scale solar £41/MWH

Returning to the subject of batteries, if we assume a BESS project built as part of one of the above wind or solar projects, it should be possible to produce a levelised estimate of costs of generation for the BESS project? Does anyone know a link for such a levelised estimate?

[hiriskpaul]

Does anyone have info on what is likely to happen to LiFePO4 battery prices over the next year or 2?

I would like to buy around 300 AH at 12V for my boat, but I might get by with a smaller one if prices are likely to drop substantially and/or limp on with lead-acid for a while longer.

[clissold345]

Does anyone have info on what is likely to happen to LiFePO4 battery prices over the next year or 2?

I would like to buy around 300 AH at 12V for my boat, but I might get by with a smaller one if prices are likely to drop substantially and/or limp on with lead-acid for a while longer.

I bought my LiFePO4 batteries two years ago from a UK reseller. The UK reseller price for similar batteries hasnt apparently dropped much (£430 two years ago, £380 now?). If you can identify a reliable Chinese seller, you can buy them much cheaper direct from China.

[hiriskpaul]

Does anyone have info on what is likely to happen to LiFePO4 battery prices over the next year or 2?

I would like to buy around 300 AH at 12V for my boat, but I might get by with a smaller one if prices are likely to drop substantially and/or limp on with lead-acid for a while longer.

I bought my LiFePO4 batteries two years ago from a UK reseller. The UK reseller price for similar batteries hasnt apparently dropped much (£430 two years ago, £380 now?). If you can identify a reliable Chinese seller, you can buy them much cheaper direct from China.

What Ah was that?

[clissold345]

What Ah was that?

I bought two 105AH LiFePO4 batteries (JBD BMS) two years ago. They were £430 each.

[odysseus2000]

Does anyone have info on what is likely to happen to LiFePO4 battery prices over the next year or 2?

I would like to buy around 300 AH at 12V for my boat, but I might get by with a smaller one if prices are likely to drop substantially and/or limp on with lead-acid for a while longer.

I bought my LiFePO4 batteries two years ago from a UK reseller. The UK reseller price for similar batteries hasnt apparently dropped much (£430 two years ago, £380 now?). If you can identify a reliable Chinese seller, you can buy them much cheaper direct from China.

Battery prices rose in 2022, but are back to falling again:

https://about.bnef.com/blog/lithium-ion ... f-139-kwh/

Unless something unexpected happens, like a war, it seems likely that prices will head down & may drop like falling off a cliff if the rumoured slow down in Chinese consumer spending is real, but buy decisions usually come down to what one needs & when it can’t be put off.

Regards,

[hiriskpaul]

What Ah was that?

I bought two 105AH LiFePO4 batteries (JBD BMS) two years ago. They were £430 each.

Fogstar.co.uk do those for £369 each at present. I have been tracking cheaper eco-worthy battery on ebay for a while. No bluetooth or heating and probably lower quality cells, but about £220 for 100Ah. The discount varies all the time. I picked up a 50Ah Eco-worthy in their Black Friday offer for £109. I have run some tests and it seems OK. I plan to use it with a 480W Yamaha electric outboard.

[clissold345]

Fogstar.co.uk do those for £369 each at present. I have been tracking cheaper eco-worthy battery on ebay for a while. No bluetooth or heating and probably lower quality cells, but about £220 for 100Ah. The discount varies all the time. I picked up a 50Ah Eco-worthy in their Black Friday offer for £109. I have run some tests and it seems OK. I plan to use it with a 480W Yamaha electric outboard.

You've done some research. That's good. You may know more than me! Fogstar's batteries look good. They're grade A cells and the BMS settings can be changed.

[hiriskpaul]

I bought my LiFePO4 batteries two years ago from a UK reseller. The UK reseller price for similar batteries hasnt apparently dropped much (£430 two years ago, £380 now?). If you can identify a reliable Chinese seller, you can buy them much cheaper direct from China.

Battery prices rose in 2022, but are back to falling again:

https://about.bnef.com/blog/lithium-ion ... f-139-kwh/

Unless something unexpected happens, like a war, it seems likely that prices will head down & may drop like falling off a cliff if the rumoured slow down in Chinese consumer spending is real, but buy decisions usually come down to what one needs & when it can’t be put off.

Regards,

Thanks, interesting article. I have notice that retail prices for LFP batteries are now in the same ballpark as deep cycle AGM lead-acid. AGM is roughly half the price, but realistically AGMs get knackered very quickly if the state of charge frequently goes below 50%. LFP OTOH can go much lower without damaging the battery. LFP will last for far more charge cycles as well, so for equivalent useable capacity LFP is similar price, half the volume, quarter the weight and lasts much longer, so no brainer really especially as it looks as though price decline is not going to be so rapid as in the past.

[odysseus2000]

Battery prices rose in 2022, but are back to falling again:

https://about.bnef.com/blog/lithium-ion ... f-139-kwh/

Unless something unexpected happens, like a war, it seems likely that prices will head down & may drop like falling off a cliff if the rumoured slow down in Chinese consumer spending is real, but buy decisions usually come down to what one needs & when it can’t be put off.

Regards,

Thanks, interesting article. I have notice that retail prices for LFP batteries are now in the same ballpark as deep cycle AGM lead-acid. AGM is roughly half the price, but realistically AGMs get knackered very quickly if the state of charge frequently goes below 50%. LFP OTOH can go much lower without damaging the battery. LFP will last for far more charge cycles as well, so for equivalent useable capacity LFP is similar price, half the volume, quarter the weight and lasts much longer, so no brainer really especially as it looks as though price decline is not going to be so rapid as in the past.

It fascinates me how folk like the barge people on the canal near me are so reluctant to give up on lead batteries. Sure at one time lead was a lot cheaper, but not now & the advantages of lfp are so overwhelming. One of them ended up in hospital after pulling a muscle straining with his lead batteries from somewhere deep within his barge, but he still loves them. There may be even better technologies coming, but lfp are so superior to lead that installations now will serve well enough and for longer than most folk care to worry about, making them super attractive. I have never seen a clear analysis of what the ingredients & manufacturing cost are to give an idea of how far they can potentially fall, but coupled with solar they are now attractive for domestic use compared to grid power which in my case is over 30p per kWh plus the various other standing charges etc. A number of folk on YouTube have been demonstrating portable batteries for off grid applications. They are still more expensive than petrol generators, but quiet & free power if coupled to portable solar arrays. I imagine that as prices fall they will be a blessing to folk living in poor countries without grids who can for the first time have power without all the overheads of buying hydrocarbon & vexations of thieves steeling power wires & when coupled with satellite broad band and decentralised currencies offer the opportunity to transform the lives of people living in such nations all over the world.

Regards,

[hiriskpaul]

Thanks, interesting article. I have notice that retail prices for LFP batteries are now in the same ballpark as deep cycle AGM lead-acid. AGM is roughly half the price, but realistically AGMs get knackered very quickly if the state of charge frequently goes below 50%. LFP OTOH can go much lower without damaging the battery. LFP will last for far more charge cycles as well, so for equivalent useable capacity LFP is similar price, half the volume, quarter the weight and lasts much longer, so no brainer really especially as it looks as though price decline is not going to be so rapid as in the past.

It fascinates me how folk like the barge people on the canal near me are so reluctant to give up on lead batteries. Sure at one time lead was a lot cheaper, but not now & the advantages of lfp are so overwhelming. One of them ended up in hospital after pulling a muscle straining with his lead batteries from somewhere deep within his barge, but he still loves them. There may be even better technologies coming, but lfp are so superior to lead that installations now will serve well enough and for longer than most folk care to worry about, making them super attractive. I have never seen a clear analysis of what the ingredients & manufacturing cost are to give an idea of how far they can potentially fall, but coupled with solar they are now attractive for domestic use compared to grid power which in my case is over 30p per kWh plus the various other standing charges etc. A number of folk on YouTube have been demonstrating portable batteries for off grid applications. They are still more expensive than petrol generators, but quiet & free power if coupled to portable solar arrays. I imagine that as prices fall they will be a blessing to folk living in poor countries without grids who can for the first time have power without all the overheads of buying hydrocarbon & vexations of thieves steeling power wires & when coupled with satellite broad band and decentralised currencies offer the opportunity to transform the lives of people living in such nations all over the world.

Regards,

There are 3 reasons I can think of why barge people and other marine users are reluctant to switch to LFP.

The first is that LFP is of no use for cranking a marine diesel, unless someone has a very large LFP bank. Lead acid is great at this and will still be required.

The second reason is that LFP cannot simply be put in instead of lead acid, even though the voltages are similar. The way LFP is charged is quite different to lead acid and the charging system will need to be upgraded to avoid damaging LFP. This is particularly a problem if charging off an alternator and the alternator itself can be damaged if used to directly charge LFP due to the very low internal resistance of LFP and/or the LFP suddenly disconnecting when the BMS judges the cells are full.

The third reason is insurance. Many insurers do not like lithium batteries. This even applies to LFP, which IMHO is safer than lead acid. Insurers are slowly coming round to LFP but insist they are professionally installed along with upgraded electrics. Anathema to many with boats as they are often competent DIYers.

[odysseus2000]

It fascinates me how folk like the barge people on the canal near me are so reluctant to give up on lead batteries. Sure at one time lead was a lot cheaper, but not now & the advantages of lfp are so overwhelming. One of them ended up in hospital after pulling a muscle straining with his lead batteries from somewhere deep within his barge, but he still loves them. There may be even better technologies coming, but lfp are so superior to lead that installations now will serve well enough and for longer than most folk care to worry about, making them super attractive. I have never seen a clear analysis of what the ingredients & manufacturing cost are to give an idea of how far they can potentially fall, but coupled with solar they are now attractive for domestic use compared to grid power which in my case is over 30p per kWh plus the various other standing charges etc. A number of folk on YouTube have been demonstrating portable batteries for off grid applications. They are still more expensive than petrol generators, but quiet & free power if coupled to portable solar arrays. I imagine that as prices fall they will be a blessing to folk living in poor countries without grids who can for the first time have power without all the overheads of buying hydrocarbon & vexations of thieves steeling power wires & when coupled with satellite broad band and decentralised currencies offer the opportunity to transform the lives of people living in such nations all over the world.

Regards,

There are 3 reasons I can think of why barge people and other marine users are reluctant to switch to LFP.

The first is that LFP is of no use for cranking a marine diesel, unless someone has a very large LFP bank. Lead acid is great at this and will still be required.

The second reason is that LFP cannot simply be put in instead of lead acid, even though the voltages are similar. The way LFP is charged is quite different to lead acid and the charging system will need to be upgraded to avoid damaging LFP. This is particularly a problem if charging off an alternator and the alternator itself can be damaged if used to directly charge LFP due to the very low internal resistance of LFP and/or the LFP suddenly disconnecting when the BMS judges the cells are full.

The third reason is insurance. Many insurers do not like lithium batteries. This even applies to LFP, which IMHO is safer than lead acid. Insurers are slowly coming round to LFP but insist they are professionally installed along with upgraded electrics. Anathema to many with boats as they are often competent DIYers.

Thank you. Super good arguments showing how little I know.

Regards,

[clissold345]

The second reason is that LFP cannot simply be put in instead of lead acid, even though the voltages are similar. The way LFP is charged is quite different to lead acid and the charging system will need to be upgraded to avoid damaging LFP. This is particularly a problem if charging off an alternator and the alternator itself can be damaged if used to directly charge LFP due to the very low internal resistance of LFP and/or the LFP suddenly disconnecting when the BMS judges the cells are full.

This is not true. LiFePO4 batteries can basically be dropped in in place of lead acid batteries. There's a 12V boating group on facebook (administered by Phil Brooke-Little), where this has been discussed for 2 or 3 years. If you search around you can find all the details there.

[88V8]

The second reason is that LFP cannot simply be put in instead of lead acid, even though the voltages are similar. The way LFP is charged is quite different to lead acid and the charging system will need to be upgraded to avoid damaging LFP. This is particularly a problem if charging off an alternator and the alternator itself can be damaged if used to directly charge LFP due to the very low internal resistance of LFP and/or the LFP suddenly disconnecting when the BMS judges the cells are full.

This is not true. LiFePO4 batteries can basically be dropped in in place of lead acid batteries. There's a 12V boating group on facebook (administered by Phil Brooke-Little), where this has been discussed for 2 or 3 years. If you search around you can find all the details there.

It used to be that they could not be charged in sub-freezing temperatures, nor allowed to fully discharge. Is this no longer the case?

V8

[hiriskpaul]

The second reason is that LFP cannot simply be put in instead of lead acid, even though the voltages are similar. The way LFP is charged is quite different to lead acid and the charging system will need to be upgraded to avoid damaging LFP. This is particularly a problem if charging off an alternator and the alternator itself can be damaged if used to directly charge LFP due to the very low internal resistance of LFP and/or the LFP suddenly disconnecting when the BMS judges the cells are full.

This is not true. LiFePO4 batteries can basically be dropped in in place of lead acid batteries. There's a 12V boating group on facebook (administered by Phil Brooke-Little), where this has been discussed for 2 or 3 years. If you search around you can find all the details there.

Everything I have read on yachting forums, with links to RV experiences, says you should not simply replace lead acid with LFPs. Definitely not for engine starting as LFP cannot deliver the required cold cranking amps. For domestic use they are fine, but as I have mentioned, they have different charging requirements. That's why modern 12V chargers have a lithium or LiFePO4 setting. In particular, LFP batteries should not be left on float, but lead acid should. When fully charged, the LFP charging should stop. Charging LFP straight from an alternator will work but there is a risk that the BMS will suddenly disconnect to prevent overcharging. This can produce a high back EMF which may fry your alternator diodes. Another risk is that when running at low speeds the alternator may overheat as the LFP internal resistance is so low. It is like shorting your alternator. There are some examples of smoking alternators on YouTube.

A recommended way to avoid the issues, which I intend to follow, is to connect a battery to battery charger (eg Victron) between the alternator and the LFP bank. The alternator is also connected directly to a lead acid starter battery. This setup ensures any spikes from the alternator are absorbed harmlessly by the starter battery.

There are other ways of handling the issues, but everything I have seen says you should not just drop in LFP batteries where you used to have lead.

I will check out the Facebook group though. Have you just dropped in LFPs where you had lead acid without changing anything?


ps, this site is useful https://batteryuniversity.com/

[hiriskpaul]

This is not true. LiFePO4 batteries can basically be dropped in in place of lead acid batteries. There's a 12V boating group on facebook (administered by Phil Brooke-Little), where this has been discussed for 2 or 3 years. If you search around you can find all the details there.

It used to be that they could not be charged in sub-freezing temperatures, nor allowed to fully discharge. Is this no longer the case?

V8

Still the case. To mitigate the problem some battery packs incorporate heating elements. I guess BEV cars most do something similar. Not an issue in my case. I use greenhouse tubular heaters in the boat over winter, connected to the marina shore supply. I would not dream of taking the boat out in sub-zero temperatures in any case!

[clissold345]

Have you just dropped in LFPs where you had lead acid without changing anything?

Yes (basically). I had two lead-acid leisure batteries, which I replaced by LiFePO4 leisure batteries. I still have a lead-acid starter battery. I replaced the split charge relay by a dumb relay. I replaced the alternator cable. The new cable is about three metres long. It limits the amps from the alternator to 40A. Without the long cable my alternator might have overheated. (The cable is rated to exceed the max output of the alternator.)

[odysseus2000]

What confuses me are the statement that lithium ion batteries can not provide enough starting amps. At my local garage I watched a mechanic start a diesel with a flat battery using what appeared to be a small lithium ion battery pack. There are several similar sized devices on eBay, all saying they can produce around 400 amps to start a car & are lithium ion battery packs.

Are these devices not as described or is there some other “magic” that allows these starting feats to happen? Or are marine diesel in need of many more than 400 amps to start?

Regards,

[hiriskpaul]

What confuses me are the statement that lithium ion batteries can not provide enough starting amps. At my local garage I watched a mechanic start a diesel with a flat battery using what appeared to be a small lithium ion battery pack. There are several similar sized devices on eBay, all saying they can produce around 400 amps to start a car & are lithium ion battery packs.

Are these devices not as described or is there some other “magic” that allows these starting feats to happen? Or are marine diesel in need of many more than 400 amps to start?

Regards,

Lithium can produce very high current but the typical, off the shelf leisure batteries have BMSs to limit the maximum discharge current. Normally the maximum discharge rate corresponds to the battery capacity in Ah, so a 100Ah battery would be limited to 100A. Any more than that and the BMS disconnects until the load is removed. Those little LiFePO4 jump starters are specifically designed to deliver much higher currents, but for short periods.

[hiriskpaul]

Have you just dropped in LFPs where you had lead acid without changing anything?

Yes (basically). I had two lead-acid leisure batteries, which I replaced by LiFePO4 leisure batteries. I still have a lead-acid starter battery. I replaced the split charge relay by a dumb relay. I replaced the alternator cable. The new cable is about three metres long. It limits the amps from the alternator to 40A. Without the long cable my alternator might have overheated. (The cable is rated to exceed the max output of the alternator.)

I have read about the long cable trick to limit the charge current, but what I was confused about is what stops battery overcharging. Or do you really on the BMS for this?