Are You Using or Abusing Your Batteries


When you head off to remote locations power is critical, so keeping your batteries charged should be at the top of your mind when you’re preparing for your next trip.

As you head off on summer adventures, it’s important to ensure you have a reliable power supply to keep living the good times. As well as keeping your appliances working, if you run out of power when off the grid, you could find yourself stranded in the middle of nowhere placing your safety at risk and ruining your trip. I speak to many 4WDers and find common mistakes when it comes to using 12v batteries.


It’s all too common for users to misuse their batteries by unknowingly discharging their batteries too deeply. Like all batteries, deep-cycle batteries have a limited number of cycles. Correct use and maintenance of your battery will ensure you receive the maximum amount of cycles and lifespan out of your battery. This information can be found in the manufacturer’s battery specifications listings. As a rule of thumb – allow one complete cycle of charge and discharge for a day’s use. A full battery cycle is one complete cycle of charge and discharge. The 50% discharge point is often chosen as a general purpose performance-optimum for easy calculation and attaining a reasonable life-capacity from your battery. It’s vital to prevent your batteries ever falling below this limit. Remember – the deeper the D.o.D the shorter the life of the battery.

To maintain healthy batteries, you must be able to replace the power you’ve drawn. Starting with fully-charged batteries after your drive to camp is best, and being conscious of your power draw throughout the day is essential to avoid killing your batteries. It’s important to remember that although your battery may be rated at 100amphour, exceeding a depth-of-discharge beyond 50% won’t do it any good. For a 100 amp-hour battery, you should base your amp draw calculations off a 50 amp-hour of useable capacity. If you have a 200 amp-hour battery, then the 50% D.o.D is 100 amp-hour of useable capacity. 50 amp-hours of usable capacity would mean that you could discharge 1 amp of current for 50 hours, or 10 amps for 5 hours, 6 amps for 8.3 hours – all depending on the amp draw of your accessories.



The best way to conserve power when we are away is measuring our power usage. Firstly, get a good quality monitor installed such as a Victron BMV700 which will give you more advanced information about volts, amps, percentage of energy consumed, and the amount of time you can continue to support the current load. You can also set an audible alarm for a specific battery voltage, record history readings and take the guesswork out of the calculations.

When measuring appliance current consumption using a monitor such as the Victron BMV700 or 702, simply turn off all appliances, and then turn on one appliance at a time and see what it is drawing. Continue to do this with all your appliances so you start to get a better understanding of your power usage. Multiply this current figure by hours gives you the amp-hours that your appliance draws from your battery.

NEW to the Baintech range is the LED volt meter. This easy to install voltmeter is capable of monitoring the voltage of your vehicle’s battery or electrical system. The voltage of a battery will let you know the usable power you have left and therefore it will give you an indication of run time remaining for your appliances


  • To avoid an unexpected delay or cutting short your trip.
  • The power load on your batteries can be large, so without regular charging they’ll die prematurely and cost you hard earnt money and time.
  • To improve the reliability of your batteries. Unhealthy batteries will discharge faster, you will find if you are running your batteries below their 50% D.OD point, the life of the battery will decrease.
  • To retain the usable capacity in your batteries which enables you to access more power before needing to recharge again.


  • Via your alternator as you drive along (without a charger). An alternator, by itself, isn’t going to fully charge your batteries. Alternator charging is becoming less of an option with the introduction of electronic smart-alternators being installed into vehicles.
  • Via solar: keep your batteries topped up with the BainTuff 180w Solar Blanket and Victron PWM. With a massive 180w power rating, the BainTuff solar blanket is one of the most powerful solar blanket options on the market today, generating up to 10amps an hour in sunny conditions.
  •  Via a DC-DC battery charger which will enable you to charge your batteries via your alternator (while you drive) or your solar (when at camp). The charger is designed specially to maintain your batteries.
  • Via an AC battery charger when you get back home to keep your batteries charged up for your next trip.

When your batteries aren’t in use, they will continue to discharge. Sulphation can occur when the battery is left sitting for long periods in an unused state, causing it to lose capacity. Unused fully charged lead-acid batteries should sit on a reading between 12.7-12.9 volts for a couple of weeks before needing any further recharge. Store in a dry, cool location.

For lead-acid batteries – the easiest way to calculate the type of charger you require is to remember the 10% rule. Select a charger that is equal to at least 10% of the battery capacity. For example, a 100Ah battery would require a 10-15A charger, whereas a 150Ah battery would require 15-20A.


If you have a summer trip planned, it’s important to remember heat can greatly affect the performance of your batteries and your onboard charging system. Most chargers are rated up to 40 degrees, and will start to lose efficiency once the temperature exceeds this. To prevent this, it is recommended that where possible, batteries and DC-DC charging set ups are installed in the rear of your vehicle in preference to the tightly packed and extremely hot engine bay.

Latest post
Share Post