PI2500B & M 12V
6
VELLEMAN
Alternators and charging systems:
a good charging system is important for the health of your batteries. Batteries are
easily damaged by poor recharging methods. When possible, recharge your batteries when they are approx. 50%
discharged. This will ensure you a longer battery life than when you discharge the batteries completely. The charging
system should be capable of delivering a charging current equal to 25% of the amp-hr capacity of the battery. E.g. if you
have a 200 amp-hrs battery, the charging system should be able to deliver 50A. The charging system must also be able
to charge each 12V battery up to approx. 14.4V and then drop back to a 'float' voltage of 13.5 to 14V (or shut down).
A typical 12V engine alternator may not be able to meet these requirements if large capacity batteries are used.
Alternators are typically rated for the current they can deliver when they are cold. In actual use, alternators heat up and
their output current capability drops by as much as 25%. Thus standard alternators with ratings of 40 to 105A will only
deliver 30 to 80A max. in actual use and even less as battery voltage rises. Many alternators produce 13.6V max. when
they are hot. As a result, a standard alternator may not be able to charge a large battery quickly and completely.
One solution is to install an alternator controller that will bypass the voltage regulator and boost the alternator's output
voltage during charging. This will increase the alternator's charging rate at higher battery voltages and ensure quicker
and more complete charging.
Another solution is to install a high-output alternator. Heavy-duty alternators rated from 100 to 140A can directly replace
standard alternators but produce the higher current and higher voltage required to charge multiple battery systems.
When recharging from AC power, use a good battery charger; do not use chargers intended for occasional recharging
of automotive starting batteries; these chargers are not intended for continuous use.
Batteries can also be recharged from alternative energy sources such as solar panels, wind, or hydro systems - always
make sure that you use an appropriate battery charge controller.
Do not operate the
PI2500B & M
directly from a charging source such as an alternator or solar panel. The inverter must
be connected to a battery or a well-regulated, high-current DC power supply to work properly.
c. Battery Cables
Proper wiring is very important for safe operation or the inverter. Low resistance wiring between battery and inverter
is essential to deliver the maximum amount of usable energy to your load.
Use only copper wire, as it has about ¼ less resistance than aluminium wire. Keep the cable as short as possible;
this will keep the overall system efficiency as high as possible, and will restrict the voltage drop between the battery
and the inverter to a minimum. If a longer cable is needed, choose a thicker cable:
Cable length
Minimum size - single cable
Minimum size - double cables
3m
85mm²
2 x 42.4mm²
4.5m
135mm²
2 x 67.5mm²
6m
175mm²
2 x 85mm²
Strip approximately 1cm of insulation from the ends of the cables to be connected to the inverter. Attach 5/16" ring
terminals to the ends of the wires and crimp them with a proper crimping tool. Another option is to use Ilsco or
equivalent box-lug terminals. The bare cable end can then be inserted into the lug terminal.
The other ends of the cables must be terminated with battery terminals that clamp to the posts on the battery.
Do not tin cable ends with solder, as this will result in a poor long-term connection.
d. Connections
Ground Wiring:
there is a lug on the inverter's rear panel to ground the chassis, and therefore the output AC ground.
The chassis ground lug must be connected to the grounding point of the location where the inverter is installed. Use
a #8 AWG or larger copper wire (preferably with green/yellow insulation) to connect the chassis ground lug to the
location's grounding point.
Do not operate the
PI2500B & M
without connecting it to ground to avoid electric shock hazard.
DC Wiring:
see "
4.d. Connections
" on page 4 for the correct way to establish the DC wiring connections.
If you are using a battery selector switch (fig.5 #2), set it to select one of the batteries/banks. Switch the inverter on
(fig.2 #2). The battery voltage indicator (fig.2 #4) should indicate 12 to 13V, depending on the voltage of the battery.
If it does not, check your power source and the connections to the inverter. Other indicators should be off.
