Lead Batteries (Pb) - ROBBE PROFI Notice D'utilisation

13.3

LEAD BATTERIES (PB)

In the field of model construction, lead batteries as drive batte-
ries are being superseded more and more by quick-charge
and lighter NC batteries. However, they are indispensable as a
starter battery, a power source for mobile 12 volt charge devi-
ces, and for high start winds as well as in the field of model
ship construction.
The charge procedure for lead batteries is completely different
than for NC/NiMH batteries, they are charged with the con-
stant voltage procedure. This charge procedure is very similar
to the Li-ion batteries (see Chp. 12.4).
Charge rate
A charge current limit is only rarely necessary as normally the
lead batteries have a high capacity and a high internal resi-
stance. In most cases, the maximum available charge current
can be set. When the target voltage has been reached, the
charge current sinks; it should be interrupted at about 0.01-
0.02 C to prevent the battery gassing (it is automatically inter-
rupted with the Profi Homecharger at about 10% of the charge
current).
Charging
Quick charging of lead batteries is critical as the charge vol-
tage is increased to 2.4 volts per cell for this which simultane-
ously represents the gassing limit and which is very dependent
on the surrounding temperature.
Charge voltage
In cycle operation, the charge end voltage can be set to 2.35
volts per cell at a surrounding temperature of 20°C (this is
automatically calculated by the Profi Homecharger via the cell
count).
Charge dependency
Lead batteries with gel-formed electrolyte are mostly charged
independent of position; in contrast, lead batteries with liquid
electrolytes must be charged in a standing position.
Self-discharging
Self-discharging of lead batteries is in the lower range with
approx. 0.2...05 % per day (at 20°C). After approx. 300 days
the battery is exhausted without even being used. Charge up
lead batteries every 10-12 months.
Storage
Storage of lead batteries in not critical and can be carried out
at - 15...+40 °C. You must make sure that lead batteries are
charged up before storage. Storage of uncharged lead batte-
ries leads to the destruction of the battery.
Service life
Depending on the application and use of the charge proce-
dure, lead batteries have a service live of approx. 500-1000
cycles. After this the battery is used up and must be disposed
of in an appropriate manner.
Discharge end voltage, exhaustive discharge
Lead batteries are very sensitive to exhaustive charging, which
leads to loss of capacity and shortening of the service life and
they must be fully recharged immediately after use to avoid
long-term damage.
The discharge end voltage should not fall short of 1.75 volts
per cell (at 20°C) (this is automatically calculated by the Profi
Homecharger via the cell count).
Profi-Home-Charger
26
When handling lead batteries, some safety precautions must
be observed to prevent bodily injury or material damage.
You assume responsibility when using these batteries.
- The gel-lead batteries most common in model construction
are mostly gas-tight and are therefore less dangerous.
- In contrast, car batteries with liquid sulphuric acid as elec-
trolyte are very dangerous because of the corrosive sulphu-
ric acid and the quick gas formation if they are overcharged.
- Never allow lead batteries to come into contact with open
flames as there is a risk of explosion.
- Never open lead batteries with force as there is a risk of
acid burn.
- Never short-circuit lead batteries as there is a risk of bur-
ning and explosion.
- Never allow secreted electrolyte to come into contact with
skin or eyes. If this should happen by accident, rinse gene-
rously with water and find a doctor. Never put batteries in
your mouth as there is a risk of poisoning.
- A charged lead battery is not a toy. Batteries should be kept
out of the reach of children.
- Observe the information from the corresponding battery
manufacturer when charging and discharging.
- Gassing of lead batteries can occur during the charge pro-
cess. For this reason, make sure there is sufficient ventila-
tion. Overcharging creates a "detonating gas" (oxyhydro-
gen gas) from a mixture of water and oxygen.
There is a risk of explosion.
Order No.
8194