Batteries

At the heart of any good marine electrical installation lies a set of good batteries, but not just any batteries!

The days of conventional wet cell lead acid batteries have been consigned to the history books buy all but the most cost cutting builders, the average new owner having neither time nor inclination to spend time topping them up with distilled water or messing with hydrometers to confirm the batteries condition.

There is now an abundance of batteries designed for specific rolls and the marine world is just one of them but why many builders still insist on fitting non marine batteries to boats is a mystery.

We fit Squadron AGM marine batteries to all our boats these being one of the most efficient cost effective solutions the following will give a little explanation of why we choose them:-

All types of battery have a expected life cycle or Cycle Life a single cycle comprising of discharging the battery to a set point and then fully recharging it.. This point of discharge varies between different types of batteries a conventional lead acid battery would probably reach this point at around 40% discharged and discharging it further would in fact damage the battery. A modern Gel/AGM battery would probably reach this point until 70% discharged batteries of this type are know as “Deep Cycle”.

The number of cycles a battery can manage effectively dictates its life expectancy but this can be extended by avoiding discharging the battery through a full cycle by not permitting it to reach it’s discharge point. Obviously this is far harder to avoid with a conventional lead acid battery with only a 40% discharge point than a Gel/AGM battery at 70%.

Not only is this point of discharge dictated by the type of battery but also the number of cycles a battery can be expected to make in its life, the following is a indication:-

Type Of Battery Discharged Point Cycle Life Conventional Lead Acid 40% 100 Sealed Lead Acid 50% 100-200 AGM 70% 300-400 GEL 80% 400 -600

 

From this you can see that without the utmost care is taken both conventional and sealed lead acid batteries without they are managed with the utmost care are not very suitable for use on a boat where high levels of discharge need to be expected daily.

So why AGM and not GEL?

To be perfectly honest price! We along with most of the big electrical manufacturers feel that the sums don’t add up the difference in number of cycles that can be reasonably expected under the realistic conditions on a boat do not justify the difference in price.
A new generation of extra deep cycle AGM batteries is now being developed that should very much narrow the gap between AGM and GEL in the future.

Regardless of the choice of batteries they need to be treated with respect and the only way this can be achieved is with the use of a battery monitor like the Mastervolt MICC which enables you to see what is actually happening, installing an expensive set of batteries without this would be like buying an expensive car and driving it blindfolded!