AGM vs traditional starting battery

Bigtalljv · 18 September 2013, 03:39

Hi,

I am at the point where I need to get a battery to think about starting my engine in the near future. I see that AGM batteries are the newer thing but did know what kind of results people have had with them. The alternatives are a traditional starting battery or an AGM. Both meet my engines electrical requirements. The AGM is twice the price. Is it twice as good? last twice as long? half the hassle?

I will eventually have two batteries, starting and house, with and automatic charging relay in between but currently have no electronics so no need to the house battery yet.

thanks,
jason

rik_elliott · 18 September 2013, 07:39

they tend to (but not necessarily) have lower capacities as they are acid starved. they can be used at any angle and stand up well to being shaken around as they cannot leak. if they get submerged somehow (bilge full of water??) it doesnt wreck them completely, as there is no way for water to get into the electrolyte. you never need to top them up. at normal charging currents they do not produce hydrogen gas so potentially lower explosion hazard.
other than that, they are lead acid batteries just the same as normal starting cells.

Dry Run · 18 September 2013, 08:38

I wouldn't bother unless you are planning on racing, or regularly taking on large amounts of water in to the battery compartment.

My experience is that they are certainly no more reliable than "normal" batteries and if they are allowed to "run flat" and left for any length of time, they will probably fail to ever take a charge again.

I don't think they recommend that you use them in conjunction with other "normal" batteries, so if you are planning on having a twin battery set-up, if you buy one, you'll have to buy another.

Pikey Dave · 18 September 2013, 09:53

I've got Optimas on BP, they've been in the console for 5 years & I've never looked at 'em. I had Optimas in the last boat for 7 years before I sold it. Fit & forget.

kubcat · 18 September 2013, 13:48

We have a pair of AGM batteries in our 2004 boat that appear original. Never had batteries last that long before. We do keep an automatic charger on them though.

Bigtalljv · 18 September 2013, 15:56

i will have an automatic charger and an automatic charging relay so they will be together but separate. The only other thing I thought of was i have read that they are sensitive to over charging. Do I need a super fancy charger?

The set it and forget it of never having to think about maintenance is really appealing. Probably the single factor I am interested in.

jason

Pikey Dave · 18 September 2013, 16:19

I use a Cetek charger on mine over the winter, never had a problem.

ncp · 18 September 2013, 16:27

Quote:

Originally Posted by Pikey Dave

I use a Cetek charger on mine over the winter, never had a problem.

bigtalljv is in California, he'll be using the boat year round!!!

<---dancing in sunglasses!

Barrowboy · 18 September 2013, 16:46

Quote:

Originally Posted by Pikey Dave

I use a Cetek charger on mine over the winter, never had a problem.

Any particular CTEK model you recommend PD?

Pikey Dave · 18 September 2013, 17:03

Quote:

Originally Posted by ncp

bigtalljv is in California, he'll be using the boat year round!!!

<---dancing in sunglasses!

Ha! nice for some

Quote:

Originally Posted by Barrowboy

Any particular CTEK model you recommend PD?

I use one of these

martini · 18 September 2013, 17:15

Here's one mans view on marine batteries:

http://www.sterling-power.com/support-faq-2.htm

burak · 18 September 2013, 19:29

I am using a standard battery for cranking and an Optima blue top for fridge etc. in my Land Rover for some time without any issues. I am using a split charger. As long as they are separated with a split charger there is nothing wrong in using different types of batteries.