long lasting battery

[James Arthur]

The choices are lithium, lithium, or lithium.

NiCads seem to last an awfully long time if you never discharge them
more than 30%--that's what most satellites have used. Some are now
using Ni-H2, whatever that is. (NiMH? I don't know how the H2 is
stored.)

I know of lead-acid batteries that've been in float service nearly
20 years.

And lithium-ion cells, at least, last a long time if the
temperatures are low and you never fully charge them, as Marte Scharz
suggests.

Not mentioned yet are the environmental specs--an important
omission.

Cheers,
James Arthur

 

[John Barrett]

----- Original Message -----
From: "Robert Baer" <[email protected]>
Newsgroups: sci.electronics.design,sci.chem.electrochem.battery
Sent: Monday, February 26, 2007 10:31 PM
Subject: Re: long lasting battery

Now where in the heck did you manufacture the voltage he needs as well
as the power/current he needs?
Maybe he needs 3V at a microamp (max); a Lithiumcoin cell will do for at
least 5 years.
Maybe he needs 440VAC three phase at 10,000 amps continuous load.
There is no clue.

Off the top of my head which is why I left the current draw as a
variable, since I didnt know what type of converter he would be using to get
his target output.... And I assumed that there would be at least a fair
amount of current draw because he mentioned AC mains power as his primary
power source... we found out later that the load was 1/2 watt or so, which
makes some of the features I tossed in unneccessary -- but the overall
architecture of the system still applies to his application. And for his
specifications.. he still needs a system that can deliver 100 watt/hours ...
which, in my opinion, still puts him in SLA territory based on the costs for
the large quantity of cells needed to provide the capacity with other
battery technologies.

12v is a pretty good general choice for a core bus voltage because there are
plenty of converters for 12v in to just about anything you want out --
including 3 phase AC -- the Outback inverters can be ganged in multi-phase
parallel arrangements for just about any arrangement of 120 single phase,
240 single phase, 120 3 phase, etc, and syncronized so that each leg can
have multiple 3000 watt inverter modules sharing the load.... run the output
through a transformer if you need 3 phase at 440v -- though if the target
were high current AC output, I would prefer to up the core bus voltage to 48
to hold the current and wire sizes down to something reasonable -- but which
is still within the input voltage range of the outback inverters -- the
additional costs for the 48v charging system are nothing compared to the
cost of the inverters in that scenario

 

[jasen]

I have a few remote sensors that needs 'embedding' in inaccessible
positions but which have to last for years (ideally 10 years).
The problem is that the mains supply will be cut off for 8 to 14 hours
every day and completely for 3 days or so every 4 to 6 weeks.
I thus need a battery that will spasmodically (4-6 weekly) be
discharged down to (say) 30% of capacity (or whatever is prudent) and
daily be discharged a few percent and subsequently recharged.


What battery chemistry am I looking at here and how must it be
electronically handled.

it depends how much power you need, it's conceivalble that a 6V alkaline
lantern battery would last the distance.

Otherwise you're looking at some sort of rechargable, and lead-acid
of some sort will be the cheapest way to go - probably a sealed or
gel type.

 

[John Fields]

The choices are lithium, lithium, or lithium.

 

[mpm]

that might be a good idea for carrying some of the load during those
planned 3 day outages -- but I wouldnt count on it as part of the load
handling capacity,

I agree. Recognizing we don't yet have enough from the original
poster to go on....
Solar power, when done correctly, is about as reliable as anything
else I've seen.
Unless you have a constant source of sunlight (or equiv), then yes,
you would still need a storage mechanism (batteries, caps, etc..)

Our own product uses solar. Other than the occasional dead panel that
arrives from China, we have ZERO problems in the field. (That
includes ice and snow, BTW) AND, our design can run simultneously via
a wall-wart, though it is never necessary to do so. There's a
blocking diode in the panel, so it's rather trivial to parallel them
with a switcher, etc... You put the regulator downstream. No big
deal.

Note to OP: For onesiew-twosies, try www.powerupco.com (USA).
They have a pretty good product, and a pretty good selection of lower-
wattage panels.
(Most vendors start at 50W and go up from there.)

HOWEVER, if the poster's application is outdoors, you have other more
important things to worry about which may not be immediately obvious:

#1 - Lightning Damage - which small solar panels definitely do a
better job with IMO.
#2 - Local building codes would likely require a GFCI breaker or
outlet to "wet" locations (i.e., outdoors).
Anyone whose played with these knows about nuisance tripping. (A
solar panel overcomes this.)
#3 - It is often much cheaper to install solar. No electricians, no
permits (usually), etc...

Not to mention, over the long term, it might even be environmentally
friendly!
So, with that said, don't be so quick to rule out Solar.

(I do admit however, that none of this addresses the issue of a 10-
year storage battery.)

-mpm

 

[Evgenij Barsukov]

You might need to handle multiple banks of backups.


NiMH.
Just monitor the discharged level and recharge when necessary.

NiMH does not last 10 years, just because of alloy electrode corrosion,
even if you don't do any cycling.

Regards,
Evgenij

 

[Evgenij Barsukov]

Hi RHRRC h.lewis


Sounds like LiPo with a max voltage below 3.9 V. Sure, you don't have 100%
of capacity then but no breakdown after 5 years.

LiPo - 10 years service? You must be kidding. It will be down by 30% of useable
capacity in 2-3 years.
The only real shot at 10 years service he has are special grade
lead-acid batteries, assuming they will be most of the time in charged
state, and occasionally maintained by adding water (although glass-mat
or gel cells might work even without maintenance).

Regards,
Yevgen

 

[Ian Stirling]

NiMH does not last 10 years, just because of alloy electrode corrosion,
even if you don't do any cycling.

NiCd - at least many of them - lasts 10 years.

I'd first ask if the 'sensor' really needs 400mW all the time.
Or if it'd work for 400mW, 1 second a minute.

 

[Gibbo]

you will need:
AGM (absorbed glass mat) sealed lead acid gel cells
a 4 stage automatic charger (bulk, boost, top, and float stages)
a load controller
a voltage stabilizer with low voltage cut-off.

given the current draw for your equipment, you need a battery bank that will
delivery (draw * 200) amp/hours of capacity... that is approx 72 hours * 3
so you never take the batteries below 1/3 discharge except in extreme
contitions

the voltage stabilizer is a 13.8 volt boost converter that will run on 10-14
volts in... as your batteries discharge, their output voltage will drop..
the stabilizer will make sure you have a precise output voltage no matter
the condition of the batteries for equipment that is sensitive to input
voltage fluctuations. The stabilizer you choose should have a low voltage
cut off so that if the battery voltage drops to 10v, everything gets cut
off -- this protects the battery from over-discharge which will cause damage
and shorten the life of the battery. Stabilizers are readily available for
up to 40 amps load.

Lastly you will need a load controller to make sure that when mains power is
up, the battery system is isolated from the load.. this should cut over when
the voltage from the mains power supply drops below 11 volts. Depending on
how criticaly your supply voltage must be regulated, you may want to put the
stabilizer after the load controller.

That entire post is just *so* wrong I wouldn't know where to start to
put it right.

 

[jasen]

NiCads seem to last an awfully long time if you never discharge them
more than 30%--that's what most satellites have used. Some are now
using Ni-H2, whatever that is. (NiMH? I don't know how the H2 is
stored.)

At a guess i'd say as a metal hydride

Bye.
Jasen

 

[James Arthur]

At a guess i'd say as a metal hydride

And for NiMH you'd be right. How 'bout in the Ni-H2 of spacecraft-
literature mention though -- is that the same thing? I'd guess it
likely is, but couldn't confirm it.

Best,
James Arthur

 

[Evgenij Barsukov]

And for NiMH you'd be right. How 'bout in the Ni-H2 of spacecraft-
literature mention though -- is that the same thing? I'd guess it
likely is, but couldn't confirm it.

It is not. They could not afford to carry heavy metal-hydride (and
good alloys were not available at that time). So they just used
H2 pressurized in a cylinder. It was half-fuel cell, half battery.
Anode was porous, set with Pd catallyst and exposed to H2, while
anode was NiO(OH)2.
These batteries are awesome in terms of longevity, but rather
expensive due to catalyst and overall balance of plant (BOP) - cylinder,
pipes, manometers etc that handling of high pressured H2 requires.

Regards,
Evgenij

 

[Evgenij Barsukov]

It is not. They could not afford to carry heavy metal-hydride (and
good alloys were not available at that time). So they just used
H2 pressurized in a cylinder. It was half-fuel cell, half battery.
Anode was porous, set with Pd catallyst and exposed to H2, while
anode was NiO(OH)2. ^^^^^^cathode

These batteries are awesome in terms of longevity, but rather
expensive due to catalyst and overall balance of plant (BOP) - cylinder,
pipes, manometers etc that handling of high pressured H2 requires.

Regards,
Evgenij

 

[joseph2k]

In sci.chem.electrochem.battery Evgenij Barsukov


NiCd - at least many of them - lasts 10 years.

I'd first ask if the 'sensor' really needs 400mW all the time.
Or if it'd work for 400mW, 1 second a minute.

NiCd lasts when really really deep cycled (discharged 99%) at least 50% of
the time. Of course if your transponder must stay up, you need two battery
packs and sufficient recharge capability for the deep cycling required.

NiMH handled similarly might last as long.

LiPoly (phosphate) a relatively new battery type may be the ticket, but they
are very expensive and do not tolerate discharge below 60% very well.

 

[joseph2k]

LiPo - 10 years service? You must be kidding. It will be down by 30% of
useable capacity in 2-3 years.
The only real shot at 10 years service he has are special grade
lead-acid batteries, assuming they will be most of the time in charged
state, and occasionally maintained by adding water (although glass-mat
or gel cells might work even without maintenance).

Regards,
Yevgen

Not by track record; see "battery university".

 

[joseph2k]

NiCads seem to last an awfully long time if you never discharge them
more than 30%--that's what most satellites have used. Some are now
using Ni-H2, whatever that is. (NiMH? I don't know how the H2 is
stored.)

Not true. Maximum life from NiCd comes from deep cycling every cycle. My
dad did the reliability studies 40 years ago. A lot of existing sattelites
use two banks of of NiCd this way.

NiMH questions? Google for it.

I know of lead-acid batteries that've been in float service nearly
20 years.

Yep, that is their forte. Possibly in a decade some variation on Lithium
will beat it is watt-hours per pound-year life.

 

[James Arthur]

James Arthur wrote:

It is not. They could not afford to carry heavy metal-hydride (and
good alloys were not available at that time). So they just used
H2 pressurized in a cylinder. It was half-fuel cell, half battery.
Anode was porous, set with Pd catallyst and exposed to H2, while
anode was NiO(OH)2.
These batteries are awesome in terms of longevity, but rather
expensive due to catalyst and overall balance of plant (BOP) - cylinder,
pipes, manometers etc that handling of high pressured H2 requires.

Regards,
Evgenij

Thanks for that concise, lucid clarification.

Best wishes,
James Arthur

 

[James Arthur]

Not true. Maximum life from NiCd comes from deep cycling every cycle. My
dad did the reliability studies 40 years ago. A lot of existing sattelites
use two banks of of NiCd this way.

I'm not an expert, I'm simply repeating what I've read. For
example, the table on page 4:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870012878_1987012878.pdf

NiMH questions? Google for it.

Since you're the second person to misinterpret my remark, I'll
explain it: I wasn't sure how Ni-H2 cells stored their hydrogen,
whether as a metal hydride--as NiMH cells do--or some other way. With
help from my internet friends, it turns out "some other way" is the
case: Ni-H2 <> NiMH.

Best regards,
James Arthur

 

[Jeff L]

The batteries I use for reserve power for my ham radio systems come from
cell phone tower reserve power systems and are rated for 10 years life --
the cell companies regulary replace them after 4 years, and they show up on
the surplus market with plenty of life left in them.

PowerSafe SBS C11

with your slow discharge rates, and if you dont deep discharge them
regularly, they would probably last a bit longer than that !!

Lead Acid car batteries often last 7 to 10 years or more here in our abusive
Canadian climates.

 

[krw]

Lead Acid car batteries often last 7 to 10 years or more here in our abusive
Canadian climates.

Yes, it's not cold that kills LA batteries, rather heat. It's only
that you don't know it's dead until it gets cold. ;-) As long as
your car is in reasonable condition car batteries will last a long
time in the frozen North (mine's six years old now). OTOH, three or
four years is about it in AZ.
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