rotate batteries?

[ALAN/ALAN D]

Ref. " Rotate Batteries "

Years ago I would have said Don't Rotate them.

Today Got my third bank of 16 304 Ah LIFeP04 installed today from Colin.
48 batteries in total.

My old Lead Acid batteries are going to be Rotated Upside down to drain the acid out before they go for scrap.

LIFeP04. Fit and forget.

[Stinsy]

Not sure this is the right place. However I don’t usually let that stop me…

Lead batteries last 4-5 years if you’re lucky and you look after them. I just replaced a couple in a UPS that I last replaced 4 years ago (you might’ve seen the thread on here) the original ones lasted 2 years.

The recieved wisdom is that lithium batteries last twice as long as lead but unlike lead they don’t become less efficient with age, the capacity reduces though.

Has anyone managed to measure any deg in their lithium batteries? Mine are 4 years old now and capacity is the same as new, so far as I’m able to measure. If they were lead I’d be looking for replacements now. What can I expect in another 4 years?

[Oliver90owner]

Lead batteries last 4-5 years if you’re lucky and you look after them. I just replaced a couple in a UPS that I last replaced 4 years ago (you might’ve seen the thread on here) the original ones lasted 2 years.

Just not true. You may be correct re a lot of lead/acid batteries, but good quality traction batteries can last many years longer.

Cheap automotive type batteries used in a cyclic charge- discharge mode is an utter waste of resources, IMO. They are designed for minimum discharge and almost immediate return to full charge.

Batteries made up with 2V cells can have huge storage capacity and were not changed like you suggest. They were maintained and regularly serviced (including regular equalising charging cycles).

I agree that replacements should, these days, be LIPO4 cell/batteries. But until existing lead/acid batteries are worn out, just keep using them. Changing, for the sake of change, is not s sensible use of resources.

[Stinsy]

Lead batteries last 4-5 years if you’re lucky and you look after them. I just replaced a couple in a UPS that I last replaced 4 years ago (you might’ve seen the thread on here) the original ones lasted 2 years.

Just not true. You may be correct re a lot of lead/acid batteries, but good quality traction batteries can last many years longer.

Cheap automotive type batteries used in a cyclic charge- discharge mode is an utter waste of resources, IMO. They are designed for minimum discharge and almost immediate return to full charge.

Batteries made up with 2V cells can have huge storage capacity and were not changed like you suggest. They were maintained and regularly serviced (including regular equalising charging cycles).

I agree that replacements should, these days, be LIPO4 cell/batteries. But until existing lead/acid batteries are worn out, just keep using them. Changing, for the sake of change, is not s sensible use of resources.

When to replace Lead with Lithium is an interesting topic. Should you wait until the batteries have failed (unlikely with the thick/heavy plates in “traction” batteries), how much efficiency dropoff should you tolerate? How much maintenance should you tolerate?

I get that you shouldn’t replace perfectly working devices for the latest-and-greatest just because. But I think we’ve reached the point where price, performance, maintenance differentials are so great that you should recycle your lead and buy lithium in all cases.

[Oliver90owner]

Stinsy,

Your first post was rational, the second was definitely irrational. Your latest post is your experience re your UPS - not necessarily storage/traction batteries as per which the OP may have installed.

As a scientist all my life, I deal with sensible facts, details and real results, not conjecture, assumptions, etc. Without knowing the particular Rolls range (although as they are not separate cells, they are not likely the highest quality that Rolls can provide) my current thinking is that due consideration should be involved in any decision, not just because lead/acid batteries are ‘horrible and dangerous’).

I have used lead/acid batteries for the best part of 70 years and never yet had one explode - although a friend did have experience of an exploded battery whilst charging a ‘long-past-its-best’ battery and angle grinding steel immediately in line with the open cells. His fault entirely. There are millions of cars and millions of security systems using them, still. Not many reported fires, explosions or other dangerous situations - as far as I can ascertain.

The acid will not be boiling, of course. Exaggeration is not required to try to make a point. It would be the mixture of hydrogen with oxygen that is explosive (and very hot) - but only when ignited by a spark or some flame, etc. The acid would burn skin, but is not as concentrated as the normal battery acid SG in a heavily sulphated or discharged battery. The eyes are the most important things to avoid permanent damage.

Even Alan, in his post, is really posting about cells, not batteries I think. I expect his battery is, in fact, a 48V battery made up of three separate strings providing 900Ah of capacity?) - but I am only guessing here, of course. A lot of others would not understand what he really means and would give it no real thought. He may even mean he has a 15kWh installation - a much better metric than Ah, IMO.

Lots of people read these threads. Please lets stick to the facts and make enlightening posts, not scaremongering to the un-knowing Joe Public.

[Stinsy]

Stinsy,

Your first post was rational, the second was definitely irrational. Your latest post is your experience re your UPS - not necessarily storage/traction batteries as per which the OP may have installed.

As a scientist all my life, I deal with sensible facts, details and real results, not conjecture, assumptions, etc. Without knowing the particular Rolls range (although as they are not separate cells, they are not likely the highest quality that Rolls can provide) my current thinking is that due consideration should be involved in any decision, not just because lead/acid batteries are ‘horrible and dangerous’).

I have used lead/acid batteries for the best part of 70 years and never yet had one explode - although a friend did have experience of an exploded battery whilst charging a ‘long-past-its-best’ battery and angle grinding steel immediately in line with the open cells. His fault entirely. There are millions of cars and millions of security systems using them, still. Not many reported fires, explosions or other dangerous situations - as far as I can ascertain.

The acid will not be boiling, of course. Exaggeration is not required to try to make a point. It would be the mixture of hydrogen with oxygen that is explosive (and very hot) - but only when ignited by a spark or some flame, etc. The acid would burn skin, but is not as concentrated as the normal battery acid SG in a heavily sulphated or discharged battery. The eyes are the most important things to avoid permanent damage.

Even Alan, in his post, is really posting about cells, not batteries I think. I expect his battery is, in fact, a 48V battery made up of three separate strings providing 900Ah of capacity?) - but I am only guessing here, of course. A lot of others would not understand what he really means and would give it no real thought. He may even mean he has a 15kWh installation - a much better metric than Ah, IMO.

Lots of people read these threads. Please lets stick to the facts and make enlightening posts, not scaremongering to the un-knowing Joe Public.

Sure the hydrogen given off by lead acid batteries can cause explosions. However you’re missing another method. Where an internal or external fault results in a short the acid can boil and cause an explosion spraying boiling acid in your face.

[nowty]

Excellent, the return of the battery wars we used to have at St Elsewhere.



Lead Acid (proper traction cells) Vs Lithium, they both have their pro's and con's, i've had both, there is no black and white answer.

Choose wisely,

Lead Acid - Pros
Cheaper outlay.
Recyclable and money back.
No BMS required.
Can be abused on overcharge.
Can use automatic watering and EQ charging systems to reduce maintenance burden.

Lead Acid - Cons
Regular overcharge required.
Difficult to move and full of liquid sulphuric acid.
Need a lot of distilled or deionised water as a consumable, can be reduced on hydrocaps.
Gives off hydrogen and noxious gasses, can be reduced with hydrocaps.
Risk of acid leaks.
Much lower life with repeated deep discharges or partial charges.
Sulfation of plates if left at partial changes.
Needs significant absorption charge time to get to full charge and to stir up the acid.
Once down to 80% life capacity they are fecked in no time.
Voltage sag under high loads.
Requires use of PPE, goggles and rubber gloves.

------------------------------------------------------------------------------------

Lithium - Pros
Once down to 80% lifetime capacity they are still useable.
Double or treble the cycles of lead acid.
More efficient, less DC in to DC out round trip loss.
Capable of very high charge / discharge rates with little voltage sag and no long absorption phase.
Maintenance free.
Stay clean.
Can be installed sideways or upside down.
Half the weight of LA.
Can be left at low SOC for long periods.

Lithium - Cons
More expensive outlay although if a DIY pack is built, can be similar in price.
If BMS fails, the pack is fecked unless you can fix it, or re-use the cells with another BMS.
Can burn or explode if abused, some chemistries like LFP are safer.
Cells become stressed (reduced life) if left at high SOC for long periods.
Currently difficult to recycle, no money back, you might have to pay to dispose.
Can be damaged by low temperature charging (lower than zero degrees).

[Sunrisemike]

Thanks all for your feedback. I have been around batteries, mostly on yachts, since the 1960's, first with ex submarine knife batteries, but mostly lead acid. Some large banks on the big sailing yachts, single cell in series to 120 volts. Since 2000, gel and AGM (one bank that melted, due to over charging form a Victron Centaur charger). In the house here, I have 4 Rolls x 6CS 27P 929 AH batteries in series. Previously, second hand Exide single cell lead acid, which lasted in total, 15 years (5 with me, they were free!). I religiously do not let them fall below 24 volts and give them a regular equalise in the summer, when there's enough solar. I think topping up every 6 weeks is ok, in my experience, and they hold there charge without a problem. However, I would like to explore the possibility of moving over to lithium batteries, happy to have 2 banks (one, the present bank) which should reduce generator time in the winter. I can see it will be a problem with the charger settings, presently set for lead acid, but perhaps there is a way round this.
so the question is, what type of battery and where to buy them?? Any advice would be most welcome...

Cheers,

Mike

[Joeboy]

Thanks all for your feedback. I have been around batteries, mostly on yachts, since the 1960's, first with ex submarine knife batteries, but mostly lead acid. Some large banks on the big sailing yachts, single cell in series to 120 volts. Since 2000, gel and AGM (one bank that melted, due to over charging form a Victron Centaur charger). In the house here, I have 4 Rolls x 6CS 27P 929 AH batteries in series. Previously, second hand Exide single cell lead acid, which lasted in total, 15 years (5 with me, they were free!). I religiously do not let them fall below 24 volts and give them a regular equalise in the summer, when there's enough solar. I think topping up every 6 weeks is ok, in my experience, and they hold there charge without a problem. However, I would like to explore the possibility of moving over to lithium batteries, happy to have 2 banks (one, the present bank) which should reduce generator time in the winter. I can see it will be a problem with the charger settings, presently set for lead acid, but perhaps there is a way round this.
so the question is, what type of battery and where to buy them?? Any advice would be most welcome...

Cheers,

Mike

Colin Deng in China was supplying grade A LFP batteries to multiple members. He worked for a company called Deriy well worth a look up.

https://camelot-forum.co.uk/phpBB3/view ... 588#p37588

[Sunrisemike]

will do, thanks.