Li-ion UPS battery substitution in UPS

On Wednesday, October 19, 2022 at 5:03:37 AM UTC-4, Robert Roland wrote:
> On Tue, 18 Oct 2022 10:43:25 -0500, Bert Hickman 
> <be...@capturedlightning.com> wrote: 
> 
> >Does anyone have any experience swapping out old lead-acid batteries for 
> >Li-ion equivalents in a UPS?
> Why would you want to? There are several parameters to consider. 
> 
> Li batteries age quite fast if kept at full charge. Lead-Acid 
> batteries last the longest when kept at full charge. 
> 
> LA's biggest disadvantages, compared to Li, is that they are heavy and 
> large. For a UPS, those disadvantages are normally not important. 
> 
> LA is simply the best choice for standby applications such as UPS, 
> emergency ligting and similar. 

Looks like a lot of people never got the memo because lithium is about all you see in standby applications these days. That doesn't mean it's right, it just means that's what just about everybody is doing.

> -- 
> RoRo

On Wednesday, October 19, 2022 at 5:52:37 AM UTC-4, a a wrote:
> On Wednesday, 19 October 2022 at 11:03:37 UTC+2, Robert Roland wrote: 
> > On Tue, 18 Oct 2022 10:43:25 -0500, Bert Hickman 
> > <be...@capturedlightning.com> wrote: 
> > 
> > >Does anyone have any experience swapping out old lead-acid batteries for 
> > >Li-ion equivalents in a UPS? 
> > Why would you want to? There are several parameters to consider. 
> > 
> > Li batteries age quite fast if kept at full charge. Lead-Acid 
> > batteries last the longest when kept at full charge. 
> > 
> > LA's biggest disadvantages, compared to Li, is that they are heavy and 
> > large. For a UPS, those disadvantages are normally not important. 
> > 
> > LA is simply the best choice for standby applications such as UPS, 
> > emergency ligting and similar. 
> > -- 
> > RoRo
> wrong 
> in your car you use exactly: lead-acid batteries 
> but you don't use car lead-acid batteries in UPS 
> since in UPS you use Gel batteries

You could most certainly use wet cell lead acid in the UPS if you're not afraid of spillage and explosion hazards.

The ultimate lead acid batteries are the AGM. You see them used a lot in solar backup applications, the reason being they can withstand very deep discharge that would destroy a lesser battery. There are automotive versions available too, and they cost top dollar, as in ???x ( changes all the time, price is coming down though) the ordinary battery, last time I checked. In addition to surviving deep discharge, they pack a helluva wallop peak current. That's why they're the battery of choice in all those compact car starter accessories you see for sale.

On 10/21/2022 5:51 PM, Fred Bloggs wrote:
> On Tuesday, October 18, 2022 at 5:10:35 PM UTC-4, Don Y wrote:
>> On 10/18/2022 8:43 AM, Bert Hickman wrote:
>>> Does anyone have any experience swapping out old lead-acid batteries for
>>> Li-ion equivalents in a UPS?
>>> 
>>> I see these batteries advertised as replacements, but I'm concerned
>>> about their safety in this application. New Li-ion UPS systems seem to
>>> be extremely expensive.
>> I wouldn't trust them -- unless the UPS manufacturer had blessed them (and
>> dubious, even then).
>> 
>> If you are having problems with battery life in UPS, look to see how it is
>> being charged. Many "cook" their batteries (poor circuit tolerances).
>> Also, they seem intent on recharging QUICKLY (in case another outage??)
>> instead of trying to prolong the batteries' service life.
>> 
>> Finally, note that many places will pay you for the lead in your old
>> batteries. If you're just using 12V7.2AHr batteries, then there's not much
>> money there (~$0.20/pound). OTOH, if you have a bigger UPS, you can get a
>> fair bit back (I got over $100 for the dead batteries in my biggest UPS)
> 
> Do you really think the modern lithium battery is just a dumb collection of
> cells. The products going after the SLA market almost certainly have
> built-in BMS ( battery management system) that cuts off the charging current
> when fully charged. And that BMS is probably made by Analog Devices. Last
> time I looked the charge management cuts off the float mode charge current
> when it has fallen to 25% or so of the initial Ipk delivered to the
> uncharged battery. And there's a sensitivity of 100:1 state of charge to the
> temperature dependent open terminal voltage, so the process requires great
> precision. Nonetheless, it's simple to very reliably put the lithium into
> the SLA charge circuit- within reason.

Do you really think a UPS treats a battery as an ideal voltage source?

Do you really think a product designed years ago can just tolerate
a replacement battery chemistry?  That the charger isn't actively
monitoring charge current?   And determining state of charge by
noticing its relationship to open cell voltage over time?

How do you think the UPS decides that the battery needs replacing?

"Gee, battery stopped taking charge current.  Has it become disconnected?
Has it failed?"

Why are lithium based solutions MULTIPLES of the price of lead-acid
solutions?  Surely they could just take an EXISTING lead acid design
and drop in a "lead-acid emulator" for the incremental cost of the
"emulator battery" over the lead-acid original.

Maybe there's more to the technology than you think!

On Saturday, 22 October 2022 at 02:15:25 UTC+1, Fred Bloggs wrote:
> On Wednesday, October 19, 2022 at 5:52:37 AM UTC-4, a a wrote: 
> > On Wednesday, 19 October 2022 at 11:03:37 UTC+2, Robert Roland wrote: 
> > > On Tue, 18 Oct 2022 10:43:25 -0500, Bert Hickman 
> > > <be...@capturedlightning.com> wrote: 
> > > 
> > > >Does anyone have any experience swapping out old lead-acid batteries for 
> > > >Li-ion equivalents in a UPS? 
> > > Why would you want to? There are several parameters to consider. 
> > > 
> > > Li batteries age quite fast if kept at full charge. Lead-Acid 
> > > batteries last the longest when kept at full charge. 
> > > 
> > > LA's biggest disadvantages, compared to Li, is that they are heavy and 
> > > large. For a UPS, those disadvantages are normally not important. 
> > > 
> > > LA is simply the best choice for standby applications such as UPS, 
> > > emergency ligting and similar. 
> > > -- 
> > > RoRo 
> > wrong 
> > in your car you use exactly: lead-acid batteries 
> > but you don't use car lead-acid batteries in UPS 
> > since in UPS you use Gel batteries
> You could most certainly use wet cell lead acid in the UPS if you're not afraid of spillage and explosion hazards. 
> 
> The ultimate lead acid batteries are the AGM. You see them used a lot in solar backup applications, the reason being they can withstand very deep discharge that would destroy a lesser battery. There are automotive versions available too, and they cost top dollar, as in ???x ( changes all the time, price is coming down though) the ordinary battery, last time I checked. In addition to surviving deep discharge, they pack a helluva wallop peak current. That's why they're the battery of choice in all those compact car starter accessories you see for sale.

Not in mine.  It uses lithium cells, is easy to hold in one hand and has started
a variety of large engines including diesel vans and a Ferrari FF.  One of the nice things
about Li cells is that the starter pack can sit on the shelf for a year without any
attention and then "just work".  (I do leave it slightly discharged to help preserve
battery life.)  It was very reasonably priced about 3 years ago, mostly because
I bought it on an Amazon "flash" sale.  I had been browsing for such things but
considered all the good ones to be too expensive.  Then an offer of a 40% discount,
valid for 1 hour, popped up and I took it.

John

On 10/22/2022 12:52 AM, John Walliker wrote:
> Not in mine.  It uses lithium cells, is easy to hold in one hand and has started
> a variety of large engines including diesel vans and a Ferrari FF.  One of the nice things
> about Li cells is that the starter pack can sit on the shelf for a year without any
> attention and then "just work".  (I do leave it slightly discharged to help preserve
> battery life.)  It was very reasonably priced about 3 years ago, mostly because
> I bought it on an Amazon "flash" sale.  I had been browsing for such things but
> considered all the good ones to be too expensive.  Then an offer of a 40% discount,
> valid for 1 hour, popped up and I took it.

But is *it* really starting the car *or* simply quickly replenishing
(topping off) the charge in the existing lead acid battery?  I.e.,
converting "unusable" coulombs to useful ones?

Most of the units I've seen have ~16AWG leads -- hardly enough to
carry the current required to turn over the engine.

Said another way, if the lead-acid battery was REMOVED from the car,
would you expect to be able to turn it over?

On Saturday, 22 October 2022 at 09:06:33 UTC+1, Don Y wrote:
> On 10/22/2022 12:52 AM, John Walliker wrote: 
> > Not in mine. It uses lithium cells, is easy to hold in one hand and has started 
> > a variety of large engines including diesel vans and a Ferrari FF. One of the nice things 
> > about Li cells is that the starter pack can sit on the shelf for a year without any 
> > attention and then "just work". (I do leave it slightly discharged to help preserve 
> > battery life.) It was very reasonably priced about 3 years ago, mostly because 
> > I bought it on an Amazon "flash" sale. I had been browsing for such things but 
> > considered all the good ones to be too expensive. Then an offer of a 40% discount, 
> > valid for 1 hour, popped up and I took it.
> But is *it* really starting the car *or* simply quickly replenishing 
> (topping off) the charge in the existing lead acid battery? I.e., 
> converting "unusable" coulombs to useful ones? 
> 
> Most of the units I've seen have ~16AWG leads -- hardly enough to 
> carry the current required to turn over the engine. 
> 
> Said another way, if the lead-acid battery was REMOVED from the car, 
> would you expect to be able to turn it over?

I think it varied according to which vehicle.  A couple of weeks ago I used it
every time I started the engine (1.8l petrol) of my car because the car battery had
developed a very high internal resistance and probably also had a shorted cell.
The voltage dropped to 6V on trying (and failing) to crank the engine.  The
charging voltage was only about 12.5V.  With the Li starter pack the engine would
start immediately.  I have now replaced the battery.
In the case of the Ferrari FF (not mine, sadly) the battery was completely dead and
it took many attempts to get it started with the Li starter pack, so the Li battery
really was doing all the work.  However, this was a 6.3 litre, 650HP V12 engine.
It did start in the end.  Its battery accepted no charge whatsoever - it would not
even run its lights after a 20 minute drive.
In the case of the diesel van, it may well have added just enough charge to make
a difference in the 20 seconds or so between connecting it and starting the engine.
My unit has very short, very thick (6AWG) cables:

no.co/gb70

Usefully, it also has a regulated 12Vdc output.

John

On 10/22/2022 3:41 AM, John Walliker wrote:
> On Saturday, 22 October 2022 at 09:06:33 UTC+1, Don Y wrote:
>> On 10/22/2022 12:52 AM, John Walliker wrote:
>>> Not in mine. It uses lithium cells, is easy to hold in one hand and has started
>>> a variety of large engines including diesel vans and a Ferrari FF. One of the nice things
>>> about Li cells is that the starter pack can sit on the shelf for a year without any
>>> attention and then "just work". (I do leave it slightly discharged to help preserve
>>> battery life.) It was very reasonably priced about 3 years ago, mostly because
>>> I bought it on an Amazon "flash" sale. I had been browsing for such things but
>>> considered all the good ones to be too expensive. Then an offer of a 40% discount,
>>> valid for 1 hour, popped up and I took it.
>> But is *it* really starting the car *or* simply quickly replenishing
>> (topping off) the charge in the existing lead acid battery? I.e.,
>> converting "unusable" coulombs to useful ones?
>>
>> Most of the units I've seen have ~16AWG leads -- hardly enough to
>> carry the current required to turn over the engine.
>>
>> Said another way, if the lead-acid battery was REMOVED from the car,
>> would you expect to be able to turn it over?
> 
> I think it varied according to which vehicle.  A couple of weeks ago I used it
> every time I started the engine (1.8l petrol) of my car because the car battery had
> developed a very high internal resistance and probably also had a shorted cell.
> The voltage dropped to 6V on trying (and failing) to crank the engine.  The
> charging voltage was only about 12.5V.  With the Li starter pack the engine would
> start immediately.  I have now replaced the battery.
> In the case of the Ferrari FF (not mine, sadly) the battery was completely dead and
> it took many attempts to get it started with the Li starter pack, so the Li battery
> really was doing all the work.  However, this was a 6.3 litre, 650HP V12 engine.
> It did start in the end.  Its battery accepted no charge whatsoever - it would not
> even run its lights after a 20 minute drive.
> In the case of the diesel van, it may well have added just enough charge to make
> a difference in the 20 seconds or so between connecting it and starting the engine.
> My unit has very short, very thick (6AWG) cables:
> 
> no.co/gb70
> 
> Usefully, it also has a regulated 12Vdc output.

That's considerably beefier than the units I've seen -- which looked more
like DMMs with dinky little (thin) leads (shirt-pocket sized)!  Hence my
suspicion that they were just (rapidly) topping off a depleted battery.

On Friday, October 21, 2022 at 9:39:16 PM UTC-4, Don Y wrote:
> On 10/21/2022 5:51 PM, Fred Bloggs wrote: 
> > On Tuesday, October 18, 2022 at 5:10:35 PM UTC-4, Don Y wrote: 
> >> On 10/18/2022 8:43 AM, Bert Hickman wrote: 
> >>> Does anyone have any experience swapping out old lead-acid batteries for 
> >>> Li-ion equivalents in a UPS? 
> >>> 
> >>> I see these batteries advertised as replacements, but I'm concerned 
> >>> about their safety in this application. New Li-ion UPS systems seem to 
> >>> be extremely expensive. 
> >> I wouldn't trust them -- unless the UPS manufacturer had blessed them (and 
> >> dubious, even then). 
> >> 
> >> If you are having problems with battery life in UPS, look to see how it is 
> >> being charged. Many "cook" their batteries (poor circuit tolerances). 
> >> Also, they seem intent on recharging QUICKLY (in case another outage??) 
> >> instead of trying to prolong the batteries' service life. 
> >> 
> >> Finally, note that many places will pay you for the lead in your old 
> >> batteries. If you're just using 12V7.2AHr batteries, then there's not much 
> >> money there (~$0.20/pound). OTOH, if you have a bigger UPS, you can get a 
> >> fair bit back (I got over $100 for the dead batteries in my biggest UPS) 
> > 
> > Do you really think the modern lithium battery is just a dumb collection of 
> > cells. The products going after the SLA market almost certainly have 
> > built-in BMS ( battery management system) that cuts off the charging current 
> > when fully charged. And that BMS is probably made by Analog Devices. Last 
> > time I looked the charge management cuts off the float mode charge current 
> > when it has fallen to 25% or so of the initial Ipk delivered to the 
> > uncharged battery. And there's a sensitivity of 100:1 state of charge to the 
> > temperature dependent open terminal voltage, so the process requires great 
> > precision. Nonetheless, it's simple to very reliably put the lithium into 
> > the SLA charge circuit- within reason.
> Do you really think a UPS treats a battery as an ideal voltage source? 
> 
> Do you really think a product designed years ago can just tolerate 
> a replacement battery chemistry? That the charger isn't actively 
> monitoring charge current? And determining state of charge by 
> noticing its relationship to open cell voltage over time? 
> 
> How do you think the UPS decides that the battery needs replacing? 
> 
> "Gee, battery stopped taking charge current. Has it become disconnected? 
> Has it failed?" 
> 
> Why are lithium based solutions MULTIPLES of the price of lead-acid 
> solutions? Surely they could just take an EXISTING lead acid design 
> and drop in a "lead-acid emulator" for the incremental cost of the 
> "emulator battery" over the lead-acid original. 
> 
> Maybe there's more to the technology than you think!

Not really. I don't care what kind of battery charge management the UPS has, the replacement battery can be made to look identical to the original. Cutting off the charge current in float mode does not mean opening a relay switch or something crude like that. The replacement battery can present enough of a self-discharge current loading to make itself look real enough.

On Saturday, October 22, 2022 at 1:06:33 AM UTC-7, Don Y wrote:
> On 10/22/2022 12:52 AM, John Walliker wrote: 
> > Not in mine. It uses lithium cells, is easy to hold in one hand and has started 
> > a variety of large engines including diesel vans and a Ferrari FF. One of the nice things 
> > about Li cells is that the starter pack can sit on the shelf for a year without any 
> > attention and then "just work". (I do leave it slightly discharged to help preserve 
> > battery life.) It was very reasonably priced about 3 years ago, mostly because 
> > I bought it on an Amazon "flash" sale. I had been browsing for such things but 
> > considered all the good ones to be too expensive. Then an offer of a 40% discount, 
> > valid for 1 hour, popped up and I took it.
> But is *it* really starting the car *or* simply quickly replenishing 
> (topping off) the charge in the existing lead acid battery? I.e., 
> converting "unusable" coulombs to useful ones? .

My Leaf won't wakeup after 2 or 3 days sleeping.  It's mostly because of the 100W power relay.  I could just jumper short the relay output, when i open up the battery next time.  For now, i just added a 200Wh (3S9P) Li power brick (around 5 pounds) to the LA battery.  The Li BMS cutoff at 11.5V when charging.  It's fine in this case.  The Li battery mostly keep the LA battery from dropping too low.

> Most of the units I've seen have ~16AWG leads -- hardly enough to 
> carry the current required to turn over the engine. 
> 
> Said another way, if the lead-acid battery was REMOVED from the car, 
> would you expect to be able to turn it over?

Yes it does.  But better to keep the LA when close to fully charge, and less cycling on the Li.

On 10/22/2022 6:34 AM, Fred Bloggs wrote:
> On Friday, October 21, 2022 at 9:39:16 PM UTC-4, Don Y wrote:
>> On 10/21/2022 5:51 PM, Fred Bloggs wrote:
>>> On Tuesday, October 18, 2022 at 5:10:35 PM UTC-4, Don Y wrote:
>>>> On 10/18/2022 8:43 AM, Bert Hickman wrote:
>>>>> Does anyone have any experience swapping out old lead-acid batteries
>>>>> for Li-ion equivalents in a UPS?
>>>>> 
>>>>> I see these batteries advertised as replacements, but I'm concerned 
>>>>> about their safety in this application. New Li-ion UPS systems seem
>>>>> to be extremely expensive.
>>>> I wouldn't trust them -- unless the UPS manufacturer had blessed them
>>>> (and dubious, even then).
>>>> 
>>>> If you are having problems with battery life in UPS, look to see how
>>>> it is being charged. Many "cook" their batteries (poor circuit
>>>> tolerances). Also, they seem intent on recharging QUICKLY (in case
>>>> another outage??) instead of trying to prolong the batteries' service
>>>> life.
>>>> 
>>>> Finally, note that many places will pay you for the lead in your old 
>>>> batteries. If you're just using 12V7.2AHr batteries, then there's not
>>>> much money there (~$0.20/pound). OTOH, if you have a bigger UPS, you
>>>> can get a fair bit back (I got over $100 for the dead batteries in my
>>>> biggest UPS)
>>> 
>>> Do you really think the modern lithium battery is just a dumb collection
>>> of cells. The products going after the SLA market almost certainly have 
>>> built-in BMS ( battery management system) that cuts off the charging
>>> current when fully charged. And that BMS is probably made by Analog
>>> Devices. Last time I looked the charge management cuts off the float
>>> mode charge current when it has fallen to 25% or so of the initial Ipk
>>> delivered to the uncharged battery. And there's a sensitivity of 100:1
>>> state of charge to the temperature dependent open terminal voltage, so
>>> the process requires great precision. Nonetheless, it's simple to very
>>> reliably put the lithium into the SLA charge circuit- within reason.
>> Do you really think a UPS treats a battery as an ideal voltage source?
>> 
>> Do you really think a product designed years ago can just tolerate a
>> replacement battery chemistry? That the charger isn't actively monitoring
>> charge current? And determining state of charge by noticing its
>> relationship to open cell voltage over time?
>> 
>> How do you think the UPS decides that the battery needs replacing?
>> 
>> "Gee, battery stopped taking charge current. Has it become disconnected? 
>> Has it failed?"
>> 
>> Why are lithium based solutions MULTIPLES of the price of lead-acid 
>> solutions? Surely they could just take an EXISTING lead acid design and
>> drop in a "lead-acid emulator" for the incremental cost of the "emulator
>> battery" over the lead-acid original.
>> 
>> Maybe there's more to the technology than you think!
> 
> Not really. I don't care what kind of battery charge management the UPS has,
> the replacement battery can be made to look identical to the original.
> Cutting off the charge current in float mode does not mean opening a relay
> switch or something crude like that. The replacement battery can present
> enough of a self-discharge current loading to make itself look real enough.

And, you'll discover on one UPS the UPS won't turn on because it doesn't
see a battery; on another, it won't run it's self checks; etc.  You don't
know what "firmware A" expects of it's battery that "firmware B" doesn't.

All of the battery-backed products I've designed predated lithium.  Put
a lithium battery in them and they'll throw a fault -- because the
battery isn't discharging at the expected rate; or is charging at
the wrong rate (dv/dt); or, the monitoring circuitry appears defective; etc.

"Hey, let's make this lithium battery look EXACTLY like a lead acid -- so
it HAS NO ADVANTAGES over a lead acid battery!  But, we can charge more
for those non-differences!"

MSRP $1,865.88   <https://www.amazon.com/dp/B08QQRFQ4W>
MSRP $2,899.99   <https://www.amazon.com/dp/B09JR6ZCQX>

$1000 premium for lithium battery pack.  Same exact run-times,
same load capacity, same networking capability, same display
(literally the same module).  Ah, but the more expensive one has
a shiny front panel (and isn't intended to be floor-standing)!

[Latter has shallower aspect ratio and weighs less -- though at the cost
of an additional rack unit.  *Might* be important in a datacenter;
doubtful a SOHO user would bother with it as he'd likely not have
many such devices, many batteries to replace, etc.  Note the number
of lead-acid offerings vs. lithium -- why is that?]