View Full Version : 12V Battery and charger question
BleuBackKoke
04-15-2008, 07:41 PM
I'm looking for advice on a good battery and charger. I'll be using the battery for a 12' aluminum boat with a 40 thrust or smaller electric motor. Size is an issue since the boat is so small.
I appreciate any advice!
deadstick
04-15-2008, 08:38 PM
Go to boaters world over by Jantzen Beach and see what they have. I picked up a single bank charger there a couple of years back for my Sportster. It was a great addition. Just plug the boat in and it is always fully charged when you leave the house. I am as cheap as anyone but if I remember correctly it was less then $50 and like I said it was well worth it. Pretty small as well.
Joes also has battery tenders that guys use for motorcycles and such. One of those may work as well if you have plenty of time between trips to achieve a full charge. You can hard wire the plug to the terminals and then just set the charger in the boat while it stores. I have one for my KTM and it works great.
I'm looking for advice on a good battery and charger. I'll be using the battery for a 12' aluminum boat with a 40 thrust or smaller electric motor. Size is an issue since the boat is so small.
I appreciate any advice!
Google "Vector battery chargers".
You want a good 3 stage charger for a deep cycle battery, it needs to put out 14+ volts, and at least 10 amps at the maximum stage. Do not use a battery maintainance charger to recharge a deep cycle battery, only to mantain a fully charged deep cycle battery. Call "Trojan Batteries", or look at their web-site and they'll confirm the above.
I think I paid about $55.00 for my Vector at an online store, it has a recondition, batt voltage, alternator check and equalization modes, and it's fully automatic so it won't overcharge. The heavy trasformer type chargers are OK for your car battery but deep cycles are a different critter and will last longer with this type of charger.
The model number of the one I have is vec1089a.
Smj
Slayer
04-16-2008, 12:39 PM
Google "Vector battery chargers".
You want a good 3 stage charger for a deep cycle battery, it needs to put out 14+ volts, and at least 10 amps at the maximum stage. Do not use a battery maintainance charger to recharge a deep cycle battery, only to mantain a fully charged deep cycle battery. Call "Trojan Batteries", or look at their web-site and they'll confirm the above.
I think I paid about $55.00 for my Vector at an online store, it has a recondition, batt voltage, alternator check and equalization modes, and it's fully automatic so it won't overcharge. The heavy trasformer type chargers are OK for your car battery but deep cycles are a different critter and will last longer with this type of charger.
The model number of the one I have is vec1089a.
Smj
I can understand the voltage but why would'nt a lower amp charger work? It's my understanding that the slower the trickle the better?
I can understand the voltage but why would'nt a lower amp charger work? It's my nderstanding that the slower the trickle the better?
A starting battery has many thin plates, and a deep cycle has fewer thicker plates. As I understand, you need the higher amperage to force the electrolite out of the thicker plates.
??As I understand it??
If you get a different story, I'm willing to listen.
Smj
Slayer
04-17-2008, 08:20 AM
Not questioning your understanding, just trying to learn. I thought voltage was pressure and amperage was flow rate? I do hope your wrong because I just bought a 8 amp charger yesterday :) I don't need another lawn mower charger :)
Slayer....My opinion would be that an 8 amp would be iffy, when you have $100.00+++ dollars wrapped up in a battery that you need to discharge and charge a bunch, I would be talkin' to the boys at Trojan to be sure.
I basicly ruined three deep cycles in 5 years by using a charger that only delivered 10.5 volts(or so) at the 10 amp rate, after some talkin' and reading and searching I came to understand better what different creatures deep cycle batteries are, compared to starting batteries that is.
Get a dependable volt meter and make SURE your new charger is putting out 14+ volts, or I will predict a short life for your deep cycle battery.
I'm curious what you find out...
Smj
CRD4Liberty
04-18-2008, 08:03 AM
Smj has it right, MinnKota and many others recommend a charger that will give "at least" a 10 amp and some recommend a larger recharge rate for long life in a trolling motor battery.
The built in charger on my boat for my 24 volt bow mount charges up to 3 batteries and it alternates from one to the other starting with the trolling motor batteries. It's a 22 amp charger.
Also I have the boat rigged to charge the batteries off my vehicle as I go from the fishing spot to home, sure saves on turn around time if your going out early and come back late.
chucks electric
04-20-2008, 01:39 AM
hello, there is some confusion as to voltage control and amperage output. a marine 3 stage charger is designed to maintain a specific voltage level for a given amount of time. the three stages are referred to absorption, bulk, and float. absorption is the point at which the voltage is held at its highest point.
deep cycle batteries having thicker plates charge slower. the difference between open circuit voltage 12.7 volts for a 12 volt battery, and absorption voltage 14.4-14.6 volts is 1.7 to 1.9 volts. drop much below this level and a deep cycle will not completely charge. plate density makes it difficult to recharge. this being the case time spent at a specific voltage that being the 14.4 to 14.6 volt is more critical that current output.
total energy discharged (measured in amp hours) from the battery will determine total energy absorbed from the charger. this process will take ? amount of time but should be in the 4-12 hour range.
the larger the battery bank the more reserve energy is available that means the batteries are discharged less meaning shorter recharge times.
there is a lot more to batteries than this but this should give you some info to make an informed decision.
to answer the output question a 10 amp charger will be good for a single battery. the math should work out like this, 10 amps X 8 hours = 80 amp hours. i would not use anything less than a group 31. most are in the 100 to 110 amp hour range.
THE MASTER HAS SPOKEN!
Bow Down....
Thanx Mr. Electric.
Good to have you pop in on these occasions, there's alot of misunderstanding on the differences between starting/deep cycle batteries. I believe alot of people end up getting much less life from their deep cycles than they should because of the confusion.
Smj
BleuBackKoke
04-20-2008, 08:12 AM
Wow...I got more info than I expectected. Thanks to everyone for their input......Your help is very much appreciated!
chucks electric
04-20-2008, 08:30 PM
you're more than welcome.
retaliate
04-20-2008, 08:53 PM
you're more than welcome.
I have a 12 amp schauer & a 15 to 20 amp charger I built in electronics school, both are automatic, I am reluctant to use my home made charger in fear that it is a bit too much for most batteries, sounds like it would be good for deep cycle batteries, what do you think? is more amps better?
chucks electric
04-21-2008, 12:59 PM
hello, if you have some hand built chargers i would be reluctant to use them. the reason being is you need to precisely control voltage, ferro-resonate type chargers can cook a battery. these types of chargers are great for commercial users with flooded batteries, because they have someone constantly maintaining batteries. if you have a dvom with a min/max memory than hook up your charger and let it run for several hours, periodically watch the meter to see if you have or had voltage creep.
retaliate
04-22-2008, 12:17 PM
hello, if you have some hand built chargers i would be reluctant to use them. the reason being is you need to precisely control voltage, ferro-resonate type chargers can cook a battery. these types of chargers are great for commercial users with flooded batteries, because they have someone constantly maintaining batteries. if you have a dvom with a min/max memory than hook up your charger and let it run for several hours, periodically watch the meter to see if you have or had voltage creep.
The one Battery charger I built in electronics school, has a massive transformer that I had to tone down with a hugh resistor, cause it was a bit much, & I beleive it's somewher in the range of 15 to 20 amps, It put's out aprox 13.8v, & it does have a automatic system that works fine, it even has a amp meter, but I doubt it's accuracy, I have charged many Batteries with it, without any problems altho I monitor them closely. My main question was is more amps better for a Deep Cycle Battery?, or a marine starting Battery?, or any Battery?