[EVDL List]

Hi Folk's,

I bought for a UPS a couple A123 standard form factor 12V (actually 13.2=3.3x4cells) 6L x 4H x 2.5W batteries that have internal balancing circuitry & arrived DOA at 0V. I was curious if anyone has experimented with them, they're 4.6ah instead of the standard lead 7.2ah counterpart used in emergency lighting and my electric lawnmower.

I wonder why the LiFePO4 has *less* capacity than lead? I assume that they put in 4 cells and have a lot of air space inside with the balancing circuitry and 30A fuse to mimic a lead battery.

It indicates 14.4 max float charge on it which is the same as lead so they're markiting it as a direct drop in replacement for lead but at 63.8% of the capacity, I doubt it will sell well. I bought 2 in the Phoenix Contact enclosure 2320351 for $790 (120whr for 2 @ 24V) and the lead counterpart that's 7.2ah is $220 (173whr for 2 @ 24V).

Have a renewable energy day,
Mark
www.REEVA.info community service RE & EV's
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[quote] Mark Hanson <marke.xxx@xxx.xxx>wrote:

>
> Hi Folk's,
>
> I bought for a UPS a couple A123 standard form factor 12V (actually
> 13.2=3.3x4cells) 6L x 4H x 2.5W batteries that have internal balancing
> circuitry & arrived DOA at 0V. I was curious if anyone has experimented
> with them, they're 4.6ah instead of the standard lead 7.2ah counterpart
> used in emergency lighting and my electric lawnmower.
>
> I wonder why the LiFePO4 has *less* capacity than lead? I assume that
> they put in 4 cells and have a lot of air space inside with the balancing
> circuitry and 30A fuse to mimic a lead battery.
>
> It indicates 14.4 max float charge on it which is the same as lead so
> they're markiting it as a direct drop in replacement for lead but at 63.8%
> of the capacity, I doubt it will sell well. I bought 2 in the Phoenix
> Contact enclosure 2320351 for $790 (120whr for 2 @ 24V) and the lead
> counterpart that's 7.2ah is $220 (173whr for 2 @ 24V).


Not sure if this relates to your UPS battery application, but the latest *
Motorcyclist* magazine has a short article on lithium replacements for
motorcycle starting/ignition batteries. There was a mention that lithium
can be susceptible to shock and vibration, and though these replacement
batteries can be much smaller than OEM lead, some manufacturers are putting
them in OEM-size cases to keep them from rattling around in the standard
battery box. In this application the big appeal is several pounds of
weight savings while still having plenty of juice to crank it over.
Capacity is rarely a concern.

Sure seems like it would be important in a UPS application though. Maybe
this is just an ill-conceived attempt at getting sales from the wrong
market? Maybe I'm missing something, but what's the advantage of lithium
in a UPS?

Chris
LeSled is for sale!
http://www.evalbum.com/274
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[EVDL List]

[quote] Chris Tromley <xxx@xxx.xxx> wrote:
> Sure seems like it would be important in a UPS application though. May=
be
> this is just an ill-conceived attempt at getting sales from the wrong
> market? Maybe I'm missing something, but what's the advantage of lithi=
um
> in a UPS?

Peukert's can really subtract run-time from a medium to heavily loaded
UPS. Lithium won't be - I wouldn't be surprised to see similar
run-times to lead under medium to heavy load. Hopefully battery life
would be better, but typically UPS batteries live their life warm and
fully charged which isn't good for calendar life.

-Dave

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