AGM BATTERIES

[mickey7]

has any one used these batteries, I understand they are very good being able to be used as a starting battery and a deep cycle battery and also fully sealed and maintenance free,seem to be the purfect battery for a boat.Any input would be appreciated.

Mickey.

[Wyoming]

Mickey, take care with the selection of your battery! The AGM style is fabulous for being able to hold (and be capable of being charged to) 100% of its charge and being able to provide a constant source of power. Fabulous for fridges and lighting but absolutely not good for big current discharges. It's OK to discharge large lumps of current (like starting an un-happy engine) but this is not what the AGM is designed for. Use them for your house batteries, not your starting batteries.

Your lead - acid batteries can be charged with a regular bog common type of charger, but they will only ever achieve about 70-75% of their Amp-hour capacity. Your AGMs need a special 2 or 3 stage charger in order for them to achieve 100% capacity.

Also, the AGMs are happy to be cycled througth around 200 fully charged / fully discharged cycles. Not so for your lead - acid batteries which will be absolutely ratsh1t after 10 such cycles. The AGMs are happy to be charged at around 30 Amps, so it takes far less time to charge them from the flat condition providing you have nice thick cables from your charging system back to the battery bank. Lead acid batteries don't like to be charged at more than around 12 Amps, then the charger will usually automatically trickle charge at 1 - 1.5 Amps until the Voltage reaches around 13.8 VDC.

In summary - select lead acid batteries for duties that are mainly high load requirements such as engine cranking. Use your AGM sealed batteries for fairly constant, fairly low current discharge situations like house batteries - hope this helps.
Neil

[dave22]

Mickey, we have got 2 blue top D34M Optima deep cycle AGM's, had them now for 2 years, used to start a 175 yammy, absolutely no problems, all we do every couple of months is put them on a standard projecta battery charger ( regulated ) if we don't use the boat, and each come up to full charge in about an hour. These batteries are designed to both start and run electronics without spikes.

[mickey7]

Thanks for your input Neil,however the retailers are telling me that hybrid AGM's perform both deep cycle with 100amps available and 750 cca for starting.They also state that fast charging up to 150 amps is possible using for example a christie/honda 12 volt generator.

Mickey

[mickey7]

Thanks for the info Dave22.

Mickey

[hornbag]

neil, ::)I have just got 2 100amp batteries for my minn kota 55lb thrust auto pilot motor and also brought a 25amp bee hive 3 stage charger , the batteries are full river brand , :o there web site is www.fullriver.com do you know or have you heard of this brand and do you think that these batteries will do the job of trolling and casting lure all day , i have a 5m hornet , as the battery s that i had in before would only last a couple of hours, the were gell cells ,all help gladly recived, :D hornbag the yellow belly hunter,

[Wyoming]

G'day hornbag - do you, by chance, come from Fountain Lakes?

OK, from the Minn Kota web site, the maximum current draw is 50 Amps and you have 200 Amp Hours capacity. In theory, in the perfect world, this equates to 4 hours of full power operation.

In the real world though, with your batteries fully charged you should get around 3 hours before the voltage drops to around 10.5 Volts at which time the batteries are considered to be fully discharged. My guess is that 3 hours is fairly conservative because it assumes that you are going flat out and drawing the full 50 Amps. In practice, you won't be running the motor all day flat chat and my guess is that will actually get 2 days of fishing assuming that you travel to your spots under your regular engine power.

If you take the value of the Amp-Hrs for your old battery and compare that to the 200 A-h of your new ones, the proportion is just about linear with the time that you can expect from the new set-up. So, if you had 50 A-h before and that would last you half a day, then you could expect 4 times the duration with your new batteries.

Finally, no, I'm sorry that I haven't heard of your particular brand of batteries, but most of the AGM sealed batteries are of identical performance. Hope this helps.

Neil

[hornbag]

THanks neil, I come from down in victoria , I got the batteries at the melbourne boat show foe 250.00 each which I thought was not two bad a price , last two batteries were both 100amp each but i think that they bad some thing wrong with them, so the had to go the new wons are the fullrive 12b but i don`t know what b stands for, again thank you for your reply..hornbag

[Wyoming]

VICTORIA!! HELL!!
You probably need bigger batteries there so that you can propel your boat through the ice....

[mickey7]

Hi guys'
go to http://www.fridge-and-solar.net/agm.htm
some usefull info.
mickey

[Wyoming]

Mickey - Val Rigoli is a top bloke and his advise is always good.I have purchased the Trojan units from him together with a compatable charger and the whole shooting match has been running really well for the last couple of years in my application. I have 2 x 100 A-hr batteries that will power my large front opening fridge (with top shelf freezer) for 5 summer days.