battery charging

(t_brown) · (t_brown) **Join Date: Feb 2006** 03-29-2006, 1:37 PM

Can you float charge a dual battery system when the battery is in the off position? the negatives are not disconnected but the positives are. I heard that it will try to "rob" the other or something like that.

(sdub) · (sdub) **Join Date: Jan 2003** 03-29-2006, 1:56 PM

You could if you hook up the charger directly to the battery...but you could only charge one at a time.

(brucemac) · (brucemac) **Join Date: Dec 2005** 03-29-2006, 3:04 PM

if you're going to spend the money to maintain your batteries get one that will do both at the same time independantly. you should be able to pick one up for $150 that will do smart 3-step charging. you could even get one that can be permanently mounted on your boat with an ac cord. a lot of people like the battery tender products. i bought a chargetek 500.

(tyler97217) · (tyler97217) **Join Date: Aug 2004** 03-29-2006, 3:37 PM

I have that one as well. I think the chargetek 500 and it charges two batteries at once. It worked great, BUT I just got word from the guy that bought my boat that one of the batteries was dead and not chargeable and that was not even after 1 yr. I wonder if it is hard on a dual battery set up with a perko.
My new set up has optima yellow tops and I want to know how to maintain them the best also....
Anyone???

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 03-29-2006, 3:54 PM

i use two separate battery tender's one for each bank. my stereo battery's have a 7 amp charger on them (reccommended for golf cart batteries) and my starting battery has the small 3 amp on it.

(brucemac) · (brucemac) **Join Date: Dec 2005** 03-29-2006, 4:07 PM

hey diggs

did you have that chargetek hooked directly up to the batteries? were they blue tops? if not, what type/brand? just curious. how old were the batteries when you installed it? just curious. would like to know more.

i talked with a few different people before i settled on that chargetek. sounded like the cats meow.

(tyler97217) · (tyler97217) **Join Date: Aug 2004** 03-29-2006, 4:30 PM

I just checked and confirmed it is the ChargeTek 500. I had it hooked up directly to each battery. The batteries on my last boat were both regular deep cycle marine batteries. They were brand new batteries and boat. I did not have the perko in any particular position and not sure if I should or if it would matter. Not sure that the ChargeTek even had anything to do with the battery going bad in less than a year, but would like to know that I am doing it right. I will be getting my new boat tomorrow and they will be yellow tops and am curious what I should be doing......

(Message edited by tyler97217 on March 29, 2006)

(breadbutta) · (breadbutta) **Join Date: Dec 2003** 03-29-2006, 4:52 PM

Sear sells a battery maintainer for $25. The wire connection stays on the battery and has a quick disconnect. Cheap and easy.

(brucemac) · (brucemac) **Join Date: Dec 2005** 03-29-2006, 5:05 PM

huh, well, i'll let you know. i certainly hope i get WAY more than a year out of mine. :-)

(cyclonecj) · (cyclonecj) **Join Date: Jul 2001** 03-29-2006, 11:25 PM

marine two bank battery battery chargers are only as far away as your nearest BASS PRO SHOPS.

One of the worst things you can do to a battery is to undercharge it, like if you have a six amp battery charger to charge two Optimas that you drain pretty hard. They will sulfate and fail in a year because you don't charge them back up.

I come in at night and plug in the charger, 2x10 amps and both batts are ready to go in 3-4 hrs, in time for first light. I use my boat a lot, it's not in a garage or used as a floating disco ball.

(tyler97217) · (tyler97217) **Join Date: Aug 2004** 03-30-2006, 7:00 AM

Psyclone
so are we saying using the Chargetek 500 (float charger) is actually bad on optimas or any battery for that matter? I will generally just bring the boat home and plug it in and the charger is permanantly connected in the boat.
What should I be doing and what product should I be using?
Thanks

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 03-30-2006, 7:20 AM

I think what Psyclone is saying is have a big enough charger to charge your batteries to 100%, this is also beneficial to your boat's electrical system, your alt. won't have to work as hard. Most battery tender chargers I've seen are small (max 3amp). That will take a long time to charge a drained battery to 100% let alone two. IF your only out on saturdays and have a few days to charge your batteries a small charger should be fine.

I do know gel/ AGM batteries charge at different rates than wet batteries.

(Message edited by acurtis_ttu on March 30, 2006)

(brucemac) · (brucemac) **Join Date: Dec 2005** 03-30-2006, 9:22 AM

i guess i just need to understand it better. if you're NOT completely draining your batteries everytime out and you bring it home and charge it up overnight and it goes to float mode you're fine. what your'e saying is if you don't FULLY RE-charge them back up it's bad? i don't get it. a charge is a charge, from what i understand how many amps is just how long it takes. i guess i see your point about not fully REcharging them, but a 3-5 amp charge is going to recharge a half drained battery overnight. am i missing something?

(cyclonecj) · (cyclonecj) **Join Date: Jul 2001** 03-30-2006, 7:24 PM

Yeah, undercharging, that's what I meant. In the summer, I go out every day, run the boat and stereo hard, then when I get home plug it in. For a while, I had a 6 amp charger that would not fully charge both batteries by the next morning, and I'd be back out on the lake the next day. That killed two optimas pretty quick. I now have a Promariner 20 amp two bank smart charger mounted on board, and it gets them charged up in 3-4 hours. I have a 90 amp alt, for my boat it would be very expensive to get a bigger alt, so I just drain the batts.

(sangerlover) · (sangerlover) **Join Date: Sep 2005** 03-30-2006, 7:34 PM

I installed this onboard charger a couple months ago. Charges each battery independently.

http://www.batterystuff.com/battery-chargers/12-volt/multi-bank/DP6-2.html

(norcalboarder) · (norcalboarder) **Join Date: Jan 2006** 04-03-2006, 2:14 PM

I've used one trickle charger (2AMPS) for two batteries hooked up to a perko switch for years and have had no problems. I put the perko on all and plug it in as soon as I get home and have never had a dead battery. As far as I know one charger should work for both batteries. How is that different than being out on the water all day and having you perko on all with your alternator charging both?

(boarder_x) · (boarder_x) **Join Date: Mar 2006** 04-03-2006, 3:19 PM

Maybe I'm missing something here. I left my stereo on one time after leaving the lake. It was on a low volume, and didn't realize it. I went to Shasta, and both batteries were dead. I had to get a jump. It took about an hour of boarding, and both batteries were completely charged. I haven't upgraded my alternator, but I know that even on houseboat trips, where my system is used for the whole day, (about 800W) all I need is to take a couple runs at the end of the day (get the engine RPM's up, and the alternator working), and I'm good. I have never had a problem with dead batteries (Except when I leave the stereo on for a week).

(Message edited by boarder_x on April 03, 2006)

(seaswirlmike) · (seaswirlmike) **Join Date: Nov 2003** 04-03-2006, 3:46 PM

we had 5 yellow tops, would never beat them down 100% but we did put a hurtin on them every weekend/many days a week. only thing we did was pop them on a 3 amp charger over night soon as we got home, wake up the next morning and do it again. never had a problem

but to answer your question i would assume that both batteries would not charge with the perko turned to the off position..... you know what they say about people who assume though hahaha