# On board charger/maintenance to charge



## New River Rat (May 30, 2018)

Hope I get some help here....I just purchased two 29 series batteries and hooked them (parallel) to my onboard charger, same as it has been done for a lotta years. The lights keep changing from maintenance to charge and back. Not at any rapid pace, but I keep going back to see what's lit several times. My continuity meter has took a crap as well, so I'm kinda like a fish outta water right now. Any ideas?


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## richg99 (May 30, 2018)

I would remove one of the parallel leads and just charge them one at a time. Once they are both fully charged, hook them back up in parallel and see if the charger still bounces back and forth.

My guess, and it is only a guess, is that one battery has taken a nearly full charge and the other needs a lot more amperage.

p.s. After many years of buying new batteries, I have come to the conclusion that NO seller ever checks the fluid level or bothers to properly maintain the batteries that are on the shelf. I've bought plenty of new batteries that needed lots of water immediately.


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## New River Rat (May 31, 2018)

richg99 said:


> I would remove one of the parallel leads and just charge them one at a time. Once they are both fully charged, hook them back up in parallel and see if the charger still bounces back and forth.
> 
> My guess, and it is only a guess, is that one battery has taken a nearly full charge and the other needs a lot more amperage.
> 
> p.s. After many years of buying new batteries, I have come to the conclusion that NO seller ever checks the fluid level or bothers to properly maintain the batteries that are on the shelf. I've bought plenty of new batteries that needed lots of water immediately.



Rich, I have both batteries and the charger in my shop. I took them off the boat because my shed that I park under is full of yard sale crap from this weekend, and every time I try to check the boat, it seems it's raining. And it involved climbing a ladder to access the set up.

I have had one battery hooked to the charger now, and after about an hour it seems to be staying in maintenance mode.


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## gnappi (May 31, 2018)

If they were in the boat and the charger was switching from charge to maintenance and back again, it may be that something in your system is powering up and pulling current? Bilge? Instruments? Internally Leaky battery?


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## New River Rat (May 31, 2018)

The first battery seemed to remain on maintenance for a few hours. Number two was charging at three hours, and now seems to switch back and forth. I'll get another battery this weekend and see what happens.


Adding: It was maint. mode this am. We'll see after 5 pm.


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## New River Rat (Jun 2, 2018)

Checked battery number 2 at 5:30 pm and 8:30 pm last night and at 4:45 am today. Looks like maintenance mode is holding now. I am going to parallel them this a.m. and let 'em sit with the charger a while. Maybe it was what Rich said about a poor charge from the store.

In the boat, the only thing on them was the Minn Kota, maybe it's a vampire, who knows? I think I'll invest in a receptacle and unplug the tm after each use and go from there.

On a side note, rather than pay for large wire by the foot, be on the look out for inexpensive booster cables. I got a 12' set of 8 gauge on the cheap.


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## New River Rat (Jun 3, 2018)

OK, I'm lost.....24 hours after returning two fully charged batteries to their parallel state and reconnecting the charger, they show they are still charging. What gives?


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## richg99 (Jun 3, 2018)

#1 Have you tried a different charger? Perhaps you can borrow one?

#2 As suggested above, perhaps something is drawing down your batteries constantly. Try removing all positive wires. Check the charger. If it is ok, then add back each wire and check the charger again, before connecting another one.


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## New River Rat (Jun 3, 2018)

Everything (both batteries, charger) is out of the boat, in the shop. There is no outside interference from electronics. The charger has successfully shown it can charge each battery individually.

As stated earlier, I let them charge parallel for about 24 hours. This morning, they were still "showing" charging. I just disconnected them and reconnected them individually. Both went instantly to maintenance mode.

FWIW, when the charger is live with no batteries, it shows maintenance mode.

Rich, I have a larger Schumacher, but it is an antique I can't trust and I ain't bringing that beast into this equation. :? 

And thanks to you guys for trying to help AND your patience!





Spoiler



EDIT: Maybe good news!



Last night I had the charger wires hooked positive to battery "A" and negative to battery "B". It is one big 12v, so this should work. It always has in the past. Like I said, this morning, they were still "showing" charging.

I just hooked the charger to terminals on one battery, they're parallel, and I *FINALLY *have maintenance mode showing.

Now I'm going to hook a receptacle to the trolling motor so that is unplugged from now on while charging and I am going back with 8 gauge wire.

This has been a learning experience and a test in patience.....


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## richg99 (Jun 3, 2018)

okay...?? When you reconnected them, and they showed Still Charging...how long did you leave it on? Some of the Smart Chargers have to be on a while to "sense" the battery condition.


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## New River Rat (Jun 3, 2018)

richg99 said:


> okay...?? When you reconnected them, and they showed Still Charging...how long did you leave it on? Some of the Smart Chargers have to be on a while to "sense" the battery condition.



When they showed Still Charging, the length of time didn't matter.....an hour or 24 hours, they showed Still Charging. With them going to maintenance, it showed Still Charging for about 10 seconds, then switched over.

Rich, I reconnected so many times in so many variations, my head is spinning. All I know is they will be hooked up exactly like they are right now when I remarry this mess to the boat. =D>


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## richg99 (Jun 3, 2018)

Well, we will all be waiting to hear how this one turns out. What a puzzle.

Good luck.


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## New River Rat (Jun 3, 2018)

richg99 said:


> okay...??




....couldn't have said it better myself. If anyone cares to contribute to this enigma, I'm all ears.

I've been working on a dual battery tray that I can't find for sale right now (i.e., one that is built worth a [email protected]).


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## frunk3 (Jun 4, 2018)

What kind of charger are you using, and how many amps is it putting out?


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## earl60446 (Jun 4, 2018)

I don't have the answer but I will tell you I had something similar with a marine battery charger I bought. I was charging 2 batteries but they were not hooked in parallel (2 bank charger). The charger never left the charging mode, 3 days later, still the same. I hooked the batteries up to my schumacher single bank charger 1 at a time and it quickly went to maintenance mode. Both batteries reacted the same. I tried a new marine 2 bank charger, same brand and model, same result. The marine charger I was using was a motorguide.


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## New River Rat (Jun 5, 2018)

frunk3 said:


> What kind of charger are you using, and how many amps is it putting out?



Cabelas/ProMariner 6 amps.....maybe7-8 years old.


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## gnappi (Jun 8, 2018)

earl60446 said:


> I don't have the answer but I will tell you I had something similar with a marine battery charger I bought. I was charging 2 batteries but they were not hooked in parallel (2 bank charger). The charger never left the charging mode, 3 days later, still the same. I hooked the batteries up to my schumacher single bank charger 1 at a time and it quickly went to maintenance mode. Both batteries reacted the same. I tried a new marine 2 bank charger, same brand and model, same result. The marine charger I was using was a motorguide.



I have a single output Shumacher and a dual output Battery Tender and both are excellent I recommend them both. While charging the charge voltage goes up to ~14.5 volts and while in maintenance mode it's 12.7-12.8.

After finishing technical college many long years ago I worked as a technician in a company that made, sold and repaired every kind of battery charger imaginable from industrial size down to home models. Since then I have always made my own chargers but not for battery maintenance.

I recently discovered a few battery charge controller chips and I may mod a few of my home built chargers for a ceiling mount multi drop charger with T-10 couplings to keep my motorcycles, lawnmower, and spare batteries for my alarm system topped up since 4 or more drop Battery Tender models are $500 and up.


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## richg99 (Jun 8, 2018)

High-level DIY. I love it!

rich


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## New River Rat (Jun 11, 2018)

I explained my situation to ProMariner and this was the reply:

_Sam,



It may be because it is one of the older style chargers and a “brand new” battery. I would suggest putting a good discharge on the batteries and then charge the batteries back up. If this behavior continues then it might be time to replace the charger.



ProMariner Support

800-824-0524

www.pmariner.com_


I was wondering if a discharge might help, so I will try that.


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## richg99 (Jun 11, 2018)

Interesting. Please keep us posted. thanks rich


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## New River Rat (Nov 4, 2018)

New River Rat said:


> I explained my situation to ProMariner and this was the reply:
> 
> _Sam,
> 
> ...






richg99 said:


> Interesting. Please keep us posted. thanks rich




OK, maybe the company knew something. After several drawdowns of the batteries, the charger has decided to work. I guess I exorcised the gremlins.....


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