onboard charger wiring question

[tchpet2]

I have a bass boat with 3 batteries. One battery is used for starting/fish finder/lights/radio. Other two batteries are wired in parallel (12 volt system) for trolling motor and one fish finder. I currently have an onboard charger that is a two bank charger (I think ? as it has 4 wires, 2 positive and 2 negative). I had it wired with the wires labeled starter hooked to the starter battery (although it also said that if using trolling battery to read instructions---which I don?t have). The second set of wires I hooked up to the other batteries (one on positive of one battery and one on negative of other battery). However, my starting battery wouldn?t be fully charged after being on charger all night and ?I think? the other two batteries were over charged as I had water bubble out (didn?t notice until I took batteries out for winter). I bought the boat used so I really know NOTHING about the charger.

So, here is what I am thinking??..either I have it wired incorrectly and the ?starter? wires need to actually go to the trolling batteries and not the starting battery, or the charger isn?t working correctly. When I originally got the boat, the starter battery wasn?t wired to the charger. Instead, both trolling batteries were wired in series (24 volt) and the charger had one set of wires going to one trolling battery and the other going to other trolling battery. Wired this way, I had no problems. However, when I switched to a 12volt trolling motor, I switched to parallel and put one set of wires to starting battery (since I added a radio that is coming off of the starting battery).

So, do I need to change the way I have things wired? Do I need to add switches? Do I need a new onboard charger? When I de-winterize the boat, I really want to get this issue solved. Also, if I need a new charger, any suggestions on what I should get?

I am sure this is as clear as mud, but I haven?t been able to find anything that answers my questions when I do a search, so I thought I would try to make this post. Sorry for the long post.

Thanks

 

[seabob4]

Re: onboard charger wiring question

Try this. Disconnect all the batts. Put the leads on 2 batts (as if charging a start batt and a house batt), and see what happens. If they both charge fine, then the charging issue is with the batt wiring, not your charger.

You CAN charge 3 batts with a 2 bank charger, but it will take much longer for the 2 batts wired in parallel to charge. Hook up the leads to one batt, the output will make it through to the second batt as the positives and negatives are the same. With batts wired in series, that doesn't work.

So try that, then we'll work from there.

 

[Silvertip]

Re: onboard charger wiring question

It appears that's the way he has it setup SeaBob. He says the starting battery isn't getting charged and the troller batteries are gassing excessively. If that is indeed the setup, it should work fine. What we don't know here is what make, model, and age of the charger is. Some chargers can boil a battery. However, one output on a pair of paralleled batteries should not pose a problem. My suggestion is to use a voltmeter to see what the charging voltage is on both pairs of outputs and make sure the ground leads on the charger are on the correct batteries (e.g., the START pair from the charger are both on the start battery and the TROLLER pair are both on the troller batteries).

 

[tchpet2]

Re: onboard charger wiring question

Boat is currently in storage so I am going from memory here...........but I am pretty sure it is an older Guest charger. I don't remember the amps on it though. I will check on it tomorrow after work. I remember trying to search for some info on it a few months ago and there wasn't much out there (on-line) so I think it is pretty old.

 

[riversouth]

Re: onboard charger wiring question

Hi, as a certified battery tech I can tell you this about your problem. To charge in paralel you have to have a charger that can charge the total amp hrs of both batteries. so if you have 2 600 amp hrs. batteries you charger has to be rated for 1200 amp hr. in series it will have to be able to output the total voltage of both batteries. so if 12v batteries your charger has to be rated for 24v.

 

[Silvertip]

Re: onboard charger wiring question

Totally not true. It is merely a matter of charger output vs battery state of discharge vs time. A 6 amp charger will charge two batteries in parallel just fine. Granted it will take some time. If what you say is true, then every bass boat and every boat on the planet that has separate starting and house batteries would continually have dead batteries. You also don't need a 24 volt charger to charge two batteries in series. Current multi-output chargers have totally isolated grounds so you can connect two 12 volt outputs to a series connected (or parallel for that matter) batteries and they will charge just fine.

 

[tchpet2]

Re: onboard charger wiring question

Well, tried to get into the storage shed today and it was frozen shut. Lucky for me, my boat is stored right next to the down spout so there was about 1.5 inch of ice about 4 feet accross the entire front of the door. Couldn't budge the door! I guess it will have to wait until the end of the week as I am really not interested in breaking that much ice

I have been looking at chargers though. I think I am just going to bite the bullet and get a 3 bank charger and hook up every battery. That should keep everything charged. I am looking at the Minn Kota MK-330. Any thoughts? I know it may be overkill, but I am not looking forward to dealling with dead batteries all season

 

[bruceb58]

Re: onboard charger wiring question

Personally, I would go with a 3 bank charger in your situation.

 

[seabob4]

Re: onboard charger wiring question

Well, tried to get into the storage shed today and it was frozen shut. Lucky for me, my boat is stored right next to the down spout so there was about 1.5 inch of ice about 4 feet accross the entire front of the door. Couldn't budge the door! I guess it will have to wait until the end of the week as I am really not interested in breaking that much ice

I have been looking at chargers though. I think I am just going to bite the bullet and get a 3 bank charger and hook up every battery. That should keep everything charged. I am looking at the Minn Kota MK-330. Any thoughts? I know it may be overkill, but I am not looking forward to dealling with dead batteries all season

This one right here...

ProMariner ProSport 20+. Totally waterproof, shifts output amps from charged batt circuit to weaker batts. AND LESS MONEY!

 

[tchpet2]

Re: onboard charger wiring question

Hi Seabob4,

I looked at that one, but most of the reviews I have read have been very negative. Lots of people on the 2nd or 3rd one after returning due to problems with them. Kind of scared me away from it.

http://reviews.basspro.com/2010/45197/reviews.htm

I read a few other reviews from some other sites as well, but most of them were negative too.

 

[seabob4]

Re: onboard charger wiring question

Hi Seabob4,

I looked at that one, but most of the reviews I have read have been very negative. Lots of people on the 2nd or 3rd one after returning due to problems with them. Kind of scared me away from it.

http://reviews.basspro.com/2010/45197/reviews.htm

I read a few other reviews from some other sites as well, but most of them were negative too.

Look at the dates. 3-4 years ago. Just saying the one I dropped in a bucket of water, charged a batt for 3 days, and is still working on my buddy's boat...well, that says enough for me.

 

[ProMarJim]

Re: onboard charger wiring question

TchPet2,

If you have any questions or concerns please let me know.

Unfortuantly we always read the negative reviews and very few positive but that is just the way it is. I have a ProSport on my boat and it has been a great product! We have many boat builders who use this product with outstanding success as it is fully waterproof. The biggest problem we have is when people use the wrong style of charger for there application.

Let me know if I can further assist you.

Jim

 

[MASTER Brian]

Re: onboard charger wiring question

I am also in the market for a 3 bank charger for my Ranger. Is that ProSport better than the ProMite? They are both made by ProMariner, haven't found the differences yet, other than a $30 price difference...

Thanks

 

[Texasmark]

Re: onboard charger wiring question

Totally not true. It is merely a matter of charger output vs battery state of discharge vs time. A 6 amp charger will charge two batteries in parallel just fine. Granted it will take some time. If what you say is true, then every bass boat and every boat on the planet that has separate starting and house batteries would continually have dead batteries. You also don't need a 24 volt charger to charge two batteries in series. Current multi-output chargers have totally isolated grounds so you can connect two 12 volt outputs to a series connected (or parallel for that matter) batteries and they will charge just fine.

Agree on all counts. No offense Mr. Riversouth, and I don't know where you got certified, but you might want to revisit the books for a refresher.

Mark

 

[tchpet2]

Re: onboard charger wiring question

Seabob4 and ProMarJim,

Well, I ordered one today. Hopefully it will take care of my issues.

I finally was able to break the ice (yeah a week later and temperatures over 40 and I still had to bust a bunch of ice) and looked at the Guest charger I have. It was an 8amp (4 on each bank). Even if it was working correctly, probably not enough to get a good charge on only about 6 hour charging time.

Thanks.