Want to get the most out of your deep cycle AGM battery?
Hi guys, Andrew here from Accelerate Auto Electrics & Air Conditioning on the Sunshine Coast.
Knowing how to correctly charge and look after your deep cycle AGM battery is crucial for optimising its performance and life span. In today’s video, we’re gonna run you through few of our tips on how to correctly use and maintain your deep cycle AGM battery.
Now just to clarify, these tips only apply to the AGM deep cycle and not your starting battery. Starting batteries are a completely different composition and are design to be used or maintained in a very different way.
So now that we’ve got the disclaimer out of the way, let’s get into the good stuff.
Okay, so let’s get into discharging, first up. If you want this guy to live a while, the last thing you want to do is discharge it too much or run it too flat. Basically, the lower the depth of discharge you take it to, the shorter its life span is gonna be.
We recommend trying not to go below 11 volts. Anything below 11 volts and you’re really causing damage to the battery. Any sort of dual battery system we wire up, we’ll always recommend using a low volt, some sort of low voltage cut out or protection system to stop this guy getting discharged too much.
Now that we’ve covered discharging, a second thing really is storage. When you store the battery, you always want to store it at a fully charged state. If you leave the AGM battery stored for a long period of time, say anything over a month in a discharged state, sulphation will always occur.
We’ll go into sulphation a bit later, but just remember, if you want this guy to last a long time, fully charge it before you store it for any amount of time.
Okay, we covered discharging, we’ve covered storage, let’s talk about charging. An AGM battery has a different internal resistance to your old school battery and it also requires a different charging method.
Whenever you charge an AGM battery, you really need a late model multistage charger. A charger that will go through an absorption, bulk and float phase.
The old charger you got, the old Arlec one that you’ve probably got in the back, will just cook this guy and destroy it and turn it into a balloon. So, whenever you charge this guy, you want to look for a modern battery charger that has an AGM setting or will detect an AGM, and shows a multistage curve. You’ll generally see five, seven to 11 stages are normally covered by your good brand chargers.
When it’s in the vehicle, it’s a different chemistry to your normal starting battery. So, your alternator isn’t really designed to charge this style of battery. Whenever you fit an AGM deep cycle battery to a vehicle, we always recommend using a DC-DC charger that again, either detects the AGM battery or can be modified to suit the AGM battery.
It requires a different charge rate your normal start battery. A DC-DC charger generally will always protect the start battery against any discharge on the AGM battery. So, the old VSR solenoid that people used to use, not such a good idea. These guys, DCDC charger, and you’ll get a much longer life span out of them.
Sulphation – Enemy of the AGM Battery
Sulphation occurs when sulfuric acid within the lead acid battery reacts to a lead sulphate on the battery’s negative plates. This reduces the surface area of the acid on the plate and makes it difficult for the battery to hold charge. The best way to prevent sulphation, once again, is to leave this guy fully charged.
We hope these tips have helped you understand how to correctly use and maintain your deep cycle AGM battery.
If you have any further questions about battery care and maintenance, give us a call on 1300 227 353, or email us at [email protected] or you can even comment below.