Charging in Excess of 1C Rate:
Every Hyperion lithium polymer battery ever produced is capable of reliable charging in excess of 2C. Yet, until
recently
,
Hyperion has only ever specified 1C charge rates. Why? Because extensive test and our experience have shown the following:
•
Charge voltage in excess of 4.2V/cell is damaging to high-rate (15C+) lithium cells in particular
•
The potential for damage from over-volt charging increases with charge rate
•
Tests of other-brand chargers prove that many are poorly regulated, and that even some of the more expensive units
regularly overcharge batteries.
•
We can only be assured that Hyperion chargers will regulate properly (test one
, to see
…)
Therefore it was
best
to specify 1C max until this time, as now we have the powerful 1210i charger with 2C max rate, TCS, and
Hyperion’s typically excellent voltage regulation.
Note: These are the charge C rates for which less than 0.3% degradation was found in Hyperion Lithium Packs:
(50-cycle tests completed at 1.0, 2.5, 2.75, 3.0C rates, 0.3% is within measurement
error
,
so not significant
,
esp
if charged at lower rate)
HP VX: 3.0C
HP CL 16C: 2.75C
HP CL 20C+: 3.0C
If 2C is Good… Why not 3C?
2C is the sensible limit for fast charging lithium polymer. Due to the CC/CV nature of the lithium charging process, the returns
from increasing charge rate diminish very quickly after 2C. That is, total charge time is only a couple minutes shorter at 3C
compared to 2C, yet charge rate has to increase 50% for that small gain. Given this, the risk/benefit equation lands squarely on
the side of 2C max rates. Additionally,
s
ince many batteries are not capable of charging reliably past 2C, chargers which do
allow 3C charging are much more likely to cause damage to batteries, or even accidents. It is simply too easy to make a mistake
with the Charge Rate setting, and there are no electronic safeguards which can be reliably employed against making such a
mistake. Finally, most chargers that are theoretically capable of 3C charging can only do so for relatively low-S, low-capacity
packs, due to inadequate max power and/or current capability. (
see below for more on max power)
If using other than
Hyperion lithium packs, consult your battery’s documentation for allowed C rates, before exceeding 1C charge rate.
Charge Amps vs. Charge Watts
The EOS 1210i is rated for 12S, 10A, with
max
power limit of 180W. These
ratings make it one of the most powerful battery chargers in the world today.
However, please note that a 10A maximum does NOT mean that every battery
pack can be charged at 10A. The total power limit of 180W will determine
where the current limits lie at higher cell counts, and the 10A limit determines
total power output at low cell counts. The table at right assumes that the pack
is fully depleted at start of charge, and the capacities shown have been
rounded up/down slightly to make it easy to follow. Variations in pack type,
state of charge, wiring employed, or presence of balancer devices
will
all
impact on the observed charge rate initially, but will not affect total charge
time greatly in most cases.
If your battery is not FULLY
depleted
, you will not
observe max CURRENT in most cases, due to CC/CV curve.
The left column shows the lithium cell count in the pack. The middle column
shows the CAPACITY that can be charged at 1C per number of cells (S). The
right column is the same, but at 2C rate. Taking 6S packs as an example, you
could charge a pack of 7900mAh at 1C, or a pack with half that capacity -
3950mAh - at 2C. Either way, the charger will be putting out about 7.9A avg.
during the initial portion of the charge curve…
So, you can see that even with a single EOS 1210i, you can charge at 2C, or nearly 2C, for some large lithium packs. For
example, packs in the range of 4S~6S, 3700~5000mAh are typically used for models in the “engine” .40ci to .90ci range, or
their equivalent (lighter versions) in Electric, such as Hyperion Extra 260 40e or Super Chipmunk 70e…
You can even charge a 4000mAh 12S pack at 1C. However, if you need a high-S, high-capacity lithium pack AND want to
charge it in 27 to 40 minutes, the Hyperion system of two packs wired in series really becomes helpful. That allows you to
separate the packs for charging on two sets of EOS1210i chargers mated to separate EOS LBA10 balancers, and charge each half
at 2C, or very nearly 2C.
As an aside, the 1210i Cooling Fan will turn on if needed. Don’t worry if it doesn’t!
A123 2300mAh: The 1210i can charge A123 2300mAh packs at their max suggested rate of 8A~10A for all packs 1S to 6S. For
a 12S A123 2300mAh pack, charge rate would be roughly 4A~5.5A, depending on state of the battery initial charge state. Note
again that A123 REQUIRE use of a balancer during charging, so a 12S pack would have to be two 6S packs charged in series
with two LBA10-A in Network Mode. (
see LBA10 manual) NOTE THAT FOR ALL LIPO and A123 CHARGING, initial charge current
depends on many factors, especially the capacity remaining in the pack before starting (partially charged packs start at lower
peak current), and state of balance.
LBA DATAPORT FEATURE
The DataPort is a 3-pin output which fits the option cable #HP-EOSLBA10-DPC. See the label to locate the DataPort on the right
side of your EOS charger. There are two main functions of the DataPort connection to LBA10 balance adapter:
*The LBA communicates with the charger, giving notification when balance charging is completed, or when an error is detected.
In both cases, the LBA tells the charger to shut down. This insures maximum safety, and saves the user from having to
manually push the charger STOP (enter) button to stop the charge-end or error tones. The lithium battery should be
disconnected from the LBA as soon as possible after charging is completed.
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