Thread:

Need a GOOD charger...

On board or portable charger? How are your batteries set up? One for starting and the other two parrallel? Are you looking for something that will charge them overnight or a trickle charger/maintainer?

Assuming you have two of them together and one by itself (starting), you really only need a two-bank. Even if you ran the big side (two together) down to 10v (minimum a stereo will run on), it will charge easily overnight on next to nothing. Plus, the alternator will have it mostly charged back up by the time you put it on the trailer.

I have the ProMariner 12 (6 amps per bank). Works great. It is really smart - when plugged in, it senses which side needs the most and applies the majority of the 12 amps to it. Then slowly evens out and settles into maintenance mode. Totally care-free. I also run AGMs (Optimas). They have been in there for 3 years now and still run all day long.

http://www.boatersworld.com/product/MP63528907.htm

if you have two deep cycle batteries with a selector switch, which battery tender should i get?

Originally Posted by Tahiti Boss21

if you have two deep cycle batteries with a selector switch, which battery tender should i get?

I like/suggest the ProMariner 12. 2 separate banks at 6 amps max each.

However, you can also just get a single-bank charger and leave your switch on ALL. Both batteries will get charged at one time.

Originally Posted by hotrod56cars

A battery tender also reduces the life span of a deep cycle battery, BTW.

I haven't ever used a Battery Tender. The ProMariner ProSport-12 that I have has not hurt my two D34Ms one bit. Three years now and they still play all day.

Originally Posted by hotrod56cars

I was just trying to state the fact that: A battery tender also reduces the life span of a deep cycle battery

I guess I don't understand this part, then. It goes against nature. A lead/acid (AGM included) battery sitting - deep cyc or not - is in a state of sulfation. It begins clinging to the plates/mats and reduces the surface area(s). The lower the voltage in the battery, the quicker this process occurs. This phenominon is well known to reduce battery life significantly. There are constantly peeps on here looking to avoid this. Usually starting out by saying their new battery(ies) has/have been dead during storage and won't take a charge anymore. A battery maintainer, good ones anyway, cycle the voltage up and down during maint to break up existing / prohibit future sulfation.

If it is your OPINION that properly maintaining a deep cyc batt will harm it - then state that. It is MY OPINION that it is unfair to mis-lead other people looking for information on a subject. You state it is a FACT and I simply have never read anything of the sort. Actually completely opposite.

See, i've always just put them on 2 amp with a normal charger, and it seems to work fine..but i know this probably is not right. The two bank battery tender will work with deep cycles or it won't? I have two different brands batteries in there, would like to avoid buying two new ones if i don't have to. They are deep cycle/starting batteries. My goal is to just have a "plug n play" charger i can set, and forget.

Thanks for the input so far though!

Originally Posted by Tahiti Boss21

See, i've always just put them on 2 amp with a normal charger, and it seems to work fine..but i know this probably is not right. The two bank battery tender will work with deep cycles or it won't? I have two different brands batteries in there, would like to avoid buying two new ones if i don't have to. They are deep cycle/starting batteries. My goal is to just have a "plug n play" charger i can set, and forget.

Thanks for the input so far though!

Any of the brands mentioned will be fine for your setup. Being two separate banks (within the charger), you can run whatever batts you want and they each have their own "brain" looking over them. Once again, the ProMariner that I have senses which battery needs the most charging and slews most of the amperage over to that bank. When they become equal, it equalizes the charge so that they finish at the same time. Then, ultimately the both (or more) go into maintenance mode and get a de-sulfating shot at random times to keep the batteries fresh and in top condition.

Yes, all of the chargers work on deeps just as well as regulars.