Voltage Drop

Strangely enough it has 1 start battery, 4 house Batterys and 1 bow thruster battery.
 
hottoddie said:
Sounds like your boat has a lot of electrical components that require the batteries be in top condition. Do you know how old the batteries are? Has the water level been checked? If you've owned the boat for 5 months and never added water to the cells then that is most likely a problem. If the batteries are 4 years or older then I would just replace them and upgrade to larger batteries if you have the room. Buy a good brand of batteries such as Interstate or Deka.

I notice there is 20 hours on rebuilt engines. That would tell me to check all the cable connections both positive and negative made to the starter and engine blocks.
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the Batterys are all good, checked the water, all good. Battery replaced summer 2015.
 
peterkvs said:
If the batteries check out fine, then it Sounds to me like you have a poor connection somewhere that is limiting the current flow resulting in a voltage drop. I'd check the battery switch and see if you have a voltage drop there when under load. To do this, put a volt meter on the two poles of your battery switch is should read zero when the switch is on. That means no voltage drop across the switch. Then put all your loads on and see if there is a voltage across the poles on the switch. If so then replace the switch. You can do this same test across relays and circuit breakers and ground busses and power busses. Eventually you will find the culprit.

Good luck,

Pete
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i thought of checking the switches, I will do that ASAP and will get back to you. Thanks!
 
Start at the source with the batteries. Once they have been 100% verified, move on to the charging systems and then to all cable connection points. Being systematic in your investigation is very important. Jumping all over the place is not the way you want to go when trouble shooting electrical problems. When checking out the charging systems, disconnect the battery charger and alternator wires from the batteries, record their output voltage readings & then re-connect them. Getting insufficient voltage readings on either one of those charging systems will greatly narrow down which way you should proceed to go next. The least expensive cure to your problems will be problematic connection points. That could include loose and/or corrosive terminations, battery switches, isolators, etc. If you discover a bad one, keep going & check them all!! Start in the ER and work back to your DC breaker panel(s). Happy hunting Oscar.
 
Four new batteries will cost you $400. This equivalent to a mechanic for 3 hours. If that does not help you may be forced to get a real mechanic. I had low voltage reading on the upper helm port engine gauge at the start of one season. I did all I could think of. Did not fix it nor could a professional. In the end it was a loose connection in the main electric panel. I found that when I was doing something else.
There are a lot of wiring harness connection on the boat. They could be your problem.
 
Had a very similar issue. Take a voltage reading from the negative terminal of your batteries to a nice clean ground on the engine block.
If you have anything other than 0.0 take a look at the battery cable that goes to the block.
 
electricaldoctor said:
Just because there is water in the batteries, that does not neccessarily make them good. Did you also do an actual load test on each one of them?
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I know the batteries are fine... The batteries and battery switches still give out 13.4 volts but by the time it gets to the panel it drops to 13. I would just like to know what tests I could do or what parts to measure?
 
electricaldoctor said:
Start at the source with the batteries. Once they have been 100% verified, move on to the charging systems and then to all cable connection points. Being systematic in your investigation is very important. Jumping all over the place is not the way you want to go when trouble shooting electrical problems. When checking out the charging systems, disconnect the battery charger and alternator wires from the batteries, record their output voltage readings & then re-connect them. Getting insufficient voltage readings on either one of those charging systems will greatly narrow down which way you should proceed to go next. The least expensive cure to your problems will be problematic connection points. That could include loose and/or corrosive terminations, battery switches, isolators, etc. If you discover a bad one, keep going & check them all!! Start in the ER and work back to your DC breaker panel(s). Happy hunting Oscar.
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Thanks, good info. I just replaced my battery charger to a pronautic 40 so that should be fine. I guess I'll just have to start checking all the connections all the way up to the panel. Thanks!
 
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