Installation manual

Once the controller recognizes that your battery charge rate has reached the highest safe

level it diverts any additional incoming power to a diversion load. Such controllers normally

allow you to set the voltage threshold at which power diversion starts according to the type

of battery in use. This threshold will also be automatically adjusted for the stages of battery

charging (absorb, equalise, float) and the battery temperature.

A non-MPPT controller should never be placed between the hydro turbine and

the battery. This is normal practice for solar PV and a battery only. Many clients

new to hydro think the same applies for hydro - it does not. Installing a solar

controller that is not designed for MPPT between the turbine and the battery will

usually destroy the controller through the hydro's high Voc off load.

Low cost solar controllers are NOT suitable for micro-hydro and wind applications as they do

not have a diversion mode option.

5.6.1. Multiple energy sources and diversion load controllers

A PowerSpout turbine can charge the same battery as a solar PV array, wind turbine and/or

other sources. This is a very normal arrangement, with many advantages for the user.

Diversion load controllers need to be sized large enough to divert all of the current from all

unregulated sources (such as direct-connected hydro and wind turbines).

If your solar system has its own controller then the diversion controller can work alongside

this but you may see some error indications on one of the two controllers as they are unlikely

to exactly agree on the best charging voltage. This need not be a problem so long as the

battery charge rate is effectively regulated.

When charging the battery from an engine driven generator you may find that the energy is

being diverted into a heater by the controller. If this is unwelcome (waste of fuel) then you

may need to adjust downward the charge voltage settings of your inverter/charger unit so

that the diversion control is not triggered. It's also possible to use a relay on the generator

output to modify the 'battery sensing' voltage to the controller so as to defeat it during

generator operation.

5.6.2. Backup diversion load controller

A secondary or backup controller is recommended in all hydro energy

systems where the turbine connects directly to the battery. Since PWM

controllers are relatively inexpensive components, redundancy will protect

the higher value components in your system in the event of failure of the

primary controller.

This picture illustrates two PWM controllers and their diversion

resistors. If there is a controller failure, the expensive battery

bank will remain protected from overcharging. Over-charging

batteries can dry out and even explode if the problem is not

recognised. Check controller operation on a regular basis by

monitoring the battery voltage and electrolyte levels and

observing the indicator lamps and load temperature.