Whaler Central - Boston Whaler Boat Information and Photos

Posted by Gil on 10/10/15 - 10:33 AM

So I have out the other night on my whaler and my gps started alarming me that my battery was low
So I check the battery gauge on my console and it was at 12v with engine running the gps kept going off showing battery at 10v then five min later 9.7v and kept dropping to 9v till finally shutting down the gps. I was worried so headed back to the launch ramp when I got them I turned the boats ignition to off then proceeded to start it back up to see if it would turn over and it did with no hesitation
So I just bought the boat and the owner said he just Installed two new batteries and showed me the receipt, he also said he just had a self charging system installed and from what he told me the batteries work together and self charge themselves as needed, a system in not familiar with. So first thing I did when I got home I checked all the wires to make sure everything was tight. Both positive and negative cables on each batteries were what seemed to be hand tight which came loose with a little quick wiggle. He had installed wing nuts to the terminals but without lock washers. So I figured that was the issue but I still wanted to get both batteries checked out so I took them out of the boat and but them on my battery tender the next morning one was completely charged and showing green, the other was indicated that it wasn't charging and was still at yellow
So I figured ok maybe it's just a bad battery I took it to Sears Service center to have them warranty it but when they but it on the tester they both tested good so they couldn't do anything with the warranty. I went home figured maybe it's my battery tender so I switched the terminals marked the battery that came up bad the first time and left it over night the next day the same battery showed up again as not charging I left it for another night and finally when I checked they were both green. So my question is should I check the alternator on the boat and if so when can it be located or should I try getting it tested somewhere else Pep boys ect.

Posted by gchuba on 10/10/15 - 6:41 PM

Trace the cables from the batteries and identify the switches and where the connections go. I would recommend a schematic of the whole wiring system. You should have that knowledge anyway in case something goes afoul while underway. There are many different ways to set up a dual battery system and until you know what you have, impossible to give any feedback. Sure sounds like one battery was cut off from the charging circuit while having a draw or maybe the low battery has an accessory on that the charging unit cannot keep up with or a battery that a draw 100%of the time even when all is shut down or ????
Garris

Posted by gchuba on 10/11/15 - 7:13 AM

When you trace the wires to the battery switch....identify the switch. If it is a Perko switch that has "battery 1; battery 2; both" the switch may be in one of the battery modes. Simple solution. Switch it to the battery that is draining. However, that switch only charges one battery at a time (the battery it is switched to). If you put it to both, the weaker battery would steal from the good one. The system is not as described "....both batteries charge....". If you have a Blue Sea "Dual Battery Plus" switch (or similar) you need to look in other areas (loose connections, accessories,etc....). Do get 100% acquainted with your wiring.
Garris

Posted by tmann45 on 10/11/15 - 7:19 AM

Gil wrote:
I turned the boats ignition to off then proceeded to start it back up to see if it would turn over and it did with no hesitation
Installed two new batteries and ... had a self charging system installed
hand tight which came loose with a little quick wiggle. He had installed wing nuts to the terminals but without lock washers. So I figured that was the issue but I still wanted to get both batteries checked out so I took them out of the boat and but them on my battery tender the next morning one was completely charged and showing green, the other was indicated that it wasn't charging and was still at yellow
I left it for another night and finally when I checked they were both green. So my question is should I check the alternator on the boat and if so .

Sounds like you have an automatic charging relay system (see: https://www.bluesea.com/products/cate...ing_Relays ) and there is a problem with it.
As Garris posted, a schematic is needed to troubleshoot this problem.

There is nothing wrong with wing nuts without lock washers if they are wrench tight, the problem is not using a wrench to tighten them. The problem is people use their fingers to tighten them and that is not tight enough, and why regular nuts are recommended because you have to use a wrench to tighten them. And whether you use wing nuts or hex nuts with or without lock washers, they should be checked for tightness with a wrench on a regular basis.

Your 'battery tender' is probably a low amp (+/- 1 A) charger and your house battery (the one that runs the GPS) was severely discharged and it will take a long time (+/- 40-hours is not out of the question) to get recharged. The other battery (engine start) was being charged by the engine and its charging system is ok.