# 12 Volt Sealed Lead Acid battery

Also called the SLA.

Very similar to the flooded battery except the acid has had a gel added to it to make it more or less solid and the pressure release lids are no longer needed.

A wide variety of capacities.

Update there is a thory that a SLA battery can be reconditioned by charging and then discharging (fast) about 10 times.

I have tried this technique with a few 6 Volt batteries with variable success, some batteries recharge and then begin to hold charge others are simply to damaged internally.

This became relevant for me as i recently found a large capacity 12 volt SLA and I’m attempting to recondition it using a battery charger and a 50W halogen bulb for discharging and I’m currently at the second discharge cycle.

So with a 50W bulb how much current will I be using?

P= V x I

50W = 12 V x ?A

50/ 12 = ?A

4.16 = A

Wires rated for 10A so no problem.

<pictures of SLA and cross section diagram>

A more portable version of the car battery weighing in at 1.5 Kg for a 7.2 amp hour battery.

Cost \$25 for 7.2 Amp hour battery

# Electrical Energy: The Inverter

400W 12V inverter with alligator clips and aluminum housing/heat sink. 240V 10A 50Hz

Simply put: the Inverter changes DC current into AC current.

Usually the voltage and frequency output are based on household AC but other voltage/frequency combos are possible.

Some inverters made for AC motors such as electric bicycles produce variable frequency 3 phase AC.

Because of the high current and voltage and current (240V 10A) produced by Inverters they are extremely dangerous.

Inverters are rated for a certain wattage output so when plugging in a device into an inverter check to make sure the inverters total wattage is not being exceeded.

Inverters usually make a alarm tone when they are running low on current, which is usually the sign the battery they are connected to is almost drained of current.

Inverters are quite inefficient with losses of 50% on inversion being typical.

If you have battery banks use DC wherever possible to effectively double your usable energy.

Some newer inverters are designed with a cigarette plug as the DC power connector.

these cannot be used for more than 150W rated devices because of the limitation of current flow through the cigarette plug.

For power consumption greater than 150W use large size alligator clips or heavy gauge battery terminal connectors.

Inverters are sold as square wave, modified sine wave or pure sine wave.

pure sine wave inverters are the most expensive and the extra expense (normally double the price of a modifies sine wave model of the same wattage) are only really noticed in someĀ  Hi-Fi and television equipment.

If the device you are plugging into an inverter contains a rectifier, the exact shape of the wave matters less at the wave is being recitficed to DC, so a modiifed sin wave would be perfectly acceptable here.

square wave inverters are acceptable for very simple application such as incandescent bulbs.