Battery problems persist

STeveZ · Post by **STeveZ** » Aug 22nd, '10, 17:00

A couple months ago I had a battery blow up:

http://bertram31.com/newbb/viewtopic.ph ... ght=#54415

I replaced the battery and chalked it up to not checking the fluid level in the spring. Last week the boat would not start (low batteries). Checked the fluid level and the old battery was fine but the new battery was very low again. Topped it off and it started, ran down the bay for fuel and it was dead again. Fortunately they had a 200 amp charger that got us going. Back to the dock and w/in days dead again.

I tightened a loose connector on one of the posts and replaced another connection that was loose and possibly undersized. At this point both batteries were reading 10.7 volts; dead. Hooked up a charger @ 40 amps for 90 minutes per side, both were reading 12.5 last night. Left a 6 amp charger on both over night. Today they're back at 10.5; even deader.

I've turned off my Dytek (fry-tek) Sea Ranger charger to try and figure out if I can get things back to normal w/ charged batteries and my alternators but that doesn't seem to be the case. The only thing that "changed" this year were a) the connection I replaced (above) and b) the forward bilge pump that I re-connected, never worked and I disconnected recently.

I guess the first step will be to jump the batteries to get the engines started and check the alternators. Next to check and/or replace the on-board charger. I can't imagine what might be happening elsewhere to kill these batteries so quickly. Hope I don't need to replace the damn batteries. Or maybe they need to be professionally cycled? I hate to do anything w/ the batteries until I know what's causing the problem. I know these things can be tough to track down but any thoughts or guesses are welcome.

In Memory Walter K · Post by **In Memory Walter K** » Aug 22nd, '10, 17:32

You're starting out the right way.You HAVE to ascertain whether or not your alternators are putting out. The same goes for your charger. Both can be easily done with a simple voltmeter. If they both check out OK, I would suggest checking out the amperage draw from each of the batteries when the boat is sitting doing nothing. Before doing that, charge up both batteries, disconnect both from everything and let them sit for 24 hours. If they keep the charge, you can be sure the problem is in your boat somewhere. On the other hand, if the voltage drops severely, it's bad batteries. If it's in the boat and there IS an amperage draw on your batteries, I'd go first to your main box and check each of the items feeding from it to try and isolate where the culprit draw is coming from. Hopefully, you'll find it there. Good luck and keep us posted.

STeveZ · Post by **STeveZ** » Aug 22nd, '10, 18:58

"I'd go first to your main box and check each of the items feeding from it to try and isolate where the culprit draw is coming from. Hopefully, you'll find it there."

Thanks Walter, sounds like a good plan but how would I "check" these items? Let's see if I can remember the switches on my (original) box; sump pump (disconnected), trim tabs, running lights, head, water (pressure) pump, bilge pump, cabin lights.

Do I just make sure they appear to be operating properly, no shorts or bare wires?

In Memory Walter K · Post by **In Memory Walter K** » Aug 22nd, '10, 19:13

That would be a start, but if you have them all in the "off" position, remove the positive connection on each, one at a time and bridge the space between the two with an ampmeter. If there is no draw showing, we can assume it's not that particular unit or the wiring to/from it. I'd ask someone who is familiar with a multi-function voltmeter/ampmeter the best way to use it to find what we are looking for. What about your radio, GPS, Loran, radar, etc., what are they connected to? Something wrong with any of them could create an electrical draw. You CAN check each one the same way as mentioned earlier. Since your trim tabs are immersed in a conductor (salt water), a break in any part or wiring would make it a suspect. If it uses 12v electricity it has to be looked at.

Eddy G · Post by **Eddy G** » Aug 23rd, '10, 07:25

A good tool to have on your boat is a clamp on amp meter. Or multi meter with the clamp on feature. You can check the current in any individual wire without disconnecting it. Fast and effective.

Eddy G.

Carl · Post by **Carl** » Aug 23rd, '10, 10:43

Eddy G wrote:A good tool to have on your boat is a clamp on amp meter. Or multi meter with the clamp on feature. You can check the current in any individual wire without disconnecting it. Fast and effective.

Eddy G.

I have yet to use one...but I have seen this tool used in diagnosing some problems around here in the shop.

I'm thinking with that meter you can see the circuit drawing power before the battery dies...a good thing. A much better method then what I was going to suggest....that would be my "low tech" method of removing everything and then adding one circuit at a time till the problem reoccurs. I'd start with a battery that I know holds a charge and add a bilge pump, then another followed by everything else you hook up.

When I saw that meter they where pricey...but have come down a good amount...think I'll order one this week...just to have.

lobsta1 · Post by **lobsta1** » Aug 23rd, '10, 11:28

I would shut all breakers & pull all fuses. Then disconnect the pos. battery cable & hook a 12V light in series. Then one by one activate each circuit. When the light goes on, you know what ckt to look at.
Al

Charlie J · Post by **Charlie J** » Aug 23rd, '10, 12:23

b) the forward bilge pump that I re-connected, never worked and I disconnected recently.

steve
this thru a red flag at me, were did you dissconnect the bilge pump, if you cut the wire leading to the pump and its still hot and not properly coverd it will draw down the batt, if only a little resistance, or laying in salt water. just a thought

STeveZ · Post by **STeveZ** » Aug 23rd, '10, 14:21

Thanks all, I've disconnected the batteries and will first make sure they'll hold a charge.

I'm going to look closer at said non-running bilge pump (problem is it is under my battery shelf so the batteries were out and in my garage when I was fooling with it. My own fault for "fixing" it and not testing it).

I'm still suspicious of the charger since overcharging is the only explanation I've heard for the disappearing battery acid.

Lobsta1, you're approach sounds like a quick and easy way to get pointed in the right direction.

Charlie · Post by **Charlie** » Aug 23rd, '10, 16:44

Once you charge the batteries put them on a 100 amp load tester. You can pick one up at a place like Harbor freight for less then $20 bucks. http://www.harborfreight.com/100-amp-6- ... 90636.html
I am willing to gamble your batteries are shot again.If they are just weak after load test you can still test your alternators. With the engine running test the voltage at the positive terminal. It should be around 13.5V. If that checks out then test your charger without the engines running. If it is putting more the 13.8V I would say it maybe overcharging. Even with a load being drawn the battery charger should keep the batteries from draining. I to would suspect the battery charger. If they do not taper off when the battery is charged they will destroy a battery in short order.

Some tools I would not be without when it comes to checking wiring problems.
Load tester, multimeter and a clamp on amp meter. Sometimes the clamp on amp meter can be a little PITA to use because you have to put the clamp around the positive wire only.
I once had a bilge pump float switch putting 12V into the bilge water. Knew I had a problem by looking a amp draw. The bilge pumps are wired to the batteries without going through the main panel. Found the problem switch by process of elimination by pulling fuses and looking for the load to drop.

STeveZ · Post by **STeveZ** » Aug 23rd, '10, 20:04

Detective work continues. Disconnected the port side, charged it at 40 amps for 90 minutes this afternoon. Came back at 5:00 and it was back down to 10.5.

Jump started the engines, both alternators putting out 13.7, good.
Turned off both engines, starboard restarted, port clicked.
Turned on charger, batteries crept up to 13.6, good, I guess.

Using my digital volt meter instead of a 12v bulb I tested all the DC breakers, nothing seemed to draw a load when flipped. (I assume this is the same as using a DC bulb?)

Monitored charge on batteries, port side fell back to 10.5, starboard side appears to be holding a charge. Connected starboard side (runs bilge pump), disconnected port side and left it on 2 amp trickle over night, we'll see, it should still be under warranty.

Everything's pointing to the bilge pump and float switch I tried to fix this spring which I'm pretty sure is wired to the port battery. Gonna have to pull the batteries, pull the shelf, remove the pump and switch. At that point the question will be whether to test each then do a straight re-wire or replace the whole shootin' match.

In Memory Walter K · Post by **In Memory Walter K** » Aug 23rd, '10, 20:48

Id reposition that pump to a place readily accessible when you lift a hatch.

Ironman · Post by **Ironman** » Aug 23rd, '10, 21:56

Can one battery draw down the better battery? I should reread but I seem to remember one batt was older..
Wayne

STeveZ · Post by **STeveZ** » Aug 23rd, '10, 22:36

Starboard side blew up in June and was replaced. Now it seems to be the problem child again, while the old port battery is holding its own.

On the starboard side I have upgraded a loose undersized connector that I didn't do a very good job on in the spring. I'm pretty sure it is one of (+) leads from the charger, but its hard to tell w/ those 210's shoe horned in there.

Also thought I had hooked up the switch and bilge pump using existing wiring but apparently I did not.

I've had the boat six years w/ no 12v problems so it seems logical to ask what has changed w/ that battery.

Carl · Post by **Carl** » Aug 24th, '10, 06:57

STeveZ wrote: Using my digital volt meter instead of a 12v bulb I tested all the DC breakers, nothing seemed to draw a load when flipped. (I assume this is the same as using a DC bulb?)

Electric is not my thing...but can you determine a load with a voltage meter? I'm guessing if it where a big draw the voltage would drop some...but you could lose some juice and still not see a Voltage drop...right? I've always thought that was the down side of a Volt Meter.

____________________________________________________

This is my Low Tech Method, takes awhile and I know there are Much Better Ways but it's simple and I understand it...I hope to get to the next level someday but until then I either grab a good mechanic to trouble shoot a big issue I cannot wait on or I resort to-

If one bilge pump is suspect...wouldn't taking it out of the loop be a good option...you have more then one pump correct? Disconnect the suspect and see what happens...or hook up a temporary pump in it's place if your worried, a spare is not a bad idea anyway.

If charger is suspect...disconnect and see. Make sure you have a pump on the good battery though, and one that is not suspect.

IRGuy · Post by **IRGuy** » Aug 24th, '10, 08:57

Steve...

I think you and I have the same problem. A couple of months ago I posted a note here saying my bank of two new Optima AGM batteries had been drawn down to almost nothing due to the combination of a failed shore powered charger and a bilge pump, but that it seemed that I had been able to bring the batteries back to life by tying each of them in parallel with a good battery and then charging the two together.

This seemed to work at first, but after a few weeks it now looks as if the recovery was short lived, and indeed my two new batteries are dead and won't hold a charge.

I suspect you have the same problem.. that your battery somehow was drawn down so far it simply won't hold a charge for any reasonable length of time. I am taking Charlie's suggestion and buying today a load tester from Harbor Freight. I drive right by one of their stores on my way to the boat.

STeveZ · Post by **STeveZ** » Aug 25th, '10, 21:24

Hope I'm not boring you guys w/ my progress reports.....

Checked the batteries today. The port side was at 10.5 despite two days of trickle charging. The starboard side, which I had held out hope for was also at 10.5, but I had left it connected to power the bilge pump.

Pulled the batteries, I'll have them tested and probably have to replace them. (Quicker to do that than drive to Harbor Freight) The newer one should be under warranty.

Checked the forward bilge pump out. It was wired incorrectly, whether it was wired in such a way that it was a drain on the batteries I couldn't say. But it is one of only a couple wiring changes I've made recently so its certainly suspect. Float switch was only working intermittently, replaced it and rewired the switch/pump properly, tested it for function.

Repeated the fuse test this time with an in-line DC bulb on each battery. Flipped all the switches and none lit up the bulb. But. When I flipped the water pressure pump switch and opened a spigot the light came on and stayed on (as long as the switch was flipped). Pressure pump did not run. My guess is that opening the spigot flipped some kind of demand switch in the pump which drew current, but not enough current could pass through the bulb to run the pump(?)

Still not sure how to test the charger. It had the batteries reading 13.0+/- when turned on which is, I guess, OK. Don't know if it is supposed to turn off at some point. Or if bad batteries would continue to demand current until they were damaged(?)

The boat mechanic on my pier told me the rule of thumb is to replace batteries as a pair since the old battery will draw down the new battery causing problems.

In Memory Walter K · Post by **In Memory Walter K** » Aug 25th, '10, 21:45

Given 2 bad batteries, the charger would keep charging. Put in fresh fully charged ones and the charger should cycle on and off as needed. Given what we now know, the charger is the least of the suspects.

Battery problems persist

Battery problems persist

Who is online