Battery Regulator

Prevents Charging Or Discharging Too Much

Your solar system needs a battery regulator to extend the working life of your storage batteries to the maximum.

A good battery regulator can charge the battery system quickly when the solar panels are catching maximum sunshine, but will switch to a trickle charge when the battery capacity is full. By doing this, the battery regulator prevents over charging, which would damage your battery and shorten its life dramatically.

Some battery regulators will also prevent your storage battery from being damaged by being discharged (emptied) too far. These regulators can be programmed or adjusted to stop draining the battery once it reaches a dangerously low voltage. For example, on a 12 volts DC home system, the danger point might be around the 11.5 volt mark. Once the DC voltage gets that low any further discharge could effectively kill the battery. So in this case, the battery regulator would just switch off the battery ... by taking it out of the citcuit until it could be recharged.

Remember, not all DC low voltage systems are 12 volts. Some systems, especially for refrigerators and other heavy-load home appliances, use 24 volts or even 48 volts DC (direct current). 12 volts DC is popular because it is used in all modern cars, while 24 volts is common in trucks (lorries). Since there is considerable voltage drop in long cable runs in DC circuits, having a higher voltage minimizes the problem. It is for this reason that AC mains electricity is so popular and universal... the higher voltage makes voltage drop almost inconsequential. But in low voltage DC circuits, you need short runs of electrical wiring, or very thick wire.

While having no electrical output from the battery would be an inconvenience, for sure, it could also save you from having to replace your storage batteries after they had been destroyed. So if you find you ran out of "juice" from the battery bank, it would be time to assess and re-calculate the number of solar panels your system requires and to calculate if the battery can store enough Amp-hours to do the job you require of it.

Amp-Hours are one way of quantifying the amount of electricity that can be stored in a battery or a cell. A 40 Amp-hour battery can, in theory, suppy 1 Ampere (1 Amp) for 40 hours, or 40 Amperes for 1 hour. I say in theory because in actual use it will always be less than the theoretical amount. So bear this in mind when you do your calculations for your solar home's actual requirements.

Next: Storage Batteries