Battery discharge

[hitthebricks]

Last year I installed 2 new deep cycle batterys for the trolling motot. After I charge the batterys they will discharge 25% over 3 days, so my questions are. When I'm not using the boat I leave the trolling motor pluged in (minn kota ap) does it discharge the batterys when not in use what would cause the discharge.

[Giant_Jackpot]

Hmmmmm. My guess is that the auto pilot circuitry does use power even with the motor off but I am not 100% sure. Probably worth a quick call to Minn-Kota to ask. What kind of charger are you using? If it is an on board 3-stage type then just leave the charger plugged in all the time as that is not going to hurt the battery. Otherwise you will have to unplug the trolling motor…..

[Down Deep]

You may have a drain on the battery from another source depending on what else is hooked to the battery. I had a problem with a drain on my starting battery. Some FM'ers suggested a battery switch which I installed. The switch solved the problem. These switches come in 1, 2 or 3 battery models and are very easy to install. If you decide to install a switch shop around. I found the same unit as much as $50 higher. My unit cost about $30.

I think that MinnKota recommeds that the motors be unplugged druing charging.

[musky hunter]

I suspect a short somewhere. Try this: charge up the batterys and disconnec the positive lead. Then test the charge after 3 days just to make sure it isn't the batteries. Then, get an ohmeter and check with everything off if there is some circuit that is closed and is draining your battery. Could be a short in the cable insulation, something in the trolling motor itself, or an unintended or forgotten connection leading to a used or unused source on the boat, like a second depth finder.

[hitthebricks]

I gave both batterys a full charge on friday without the trolling moter connected, had a strong full charge fri. night but only a 3/4 charge in the morning when I got to the river and "threw it in" (remenets of the Billy Bass song) Anyways, how do you check a battery to see if it bad and not holding a charge? Thanks HTB

[HaywardBound]

Quote:

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Anyways, how do you check a battery to see if it bad and not holding a charge? Thanks HTB

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This is a very nice tool to own. You can check your voltage, check your charging system, and also do a load test to see if your battery will hold a charge. You can use it on cars, boats, lawnmowers, and is very easy to use.

The one pictured is on sale for $14.99 right now, otherwise they are around $20-30.

Jon

[fish2live]

i always thought that if you charge the bat and bring it to batts plus they will do a load test ans see if there is something wrong.

[countryboy9799]

Quote:

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I gave both batterys a full charge on friday without the trolling moter connected, had a strong full charge fri. night but only a 3/4 charge in the morning when I got to the river and "threw it in" (remenets of the Billy Bass song) Anyways, how do you check a battery to see if it bad and not holding a charge? Thanks HTB

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When you say it is at 3/4 charge I am assuming you are talking about the meter on the trolling motor. I would like to know what the voltages are and that might give us a better indicator of whats going on. On my autopilot which is 10 years old it said to unhook it if you weren't going to use it for a certian amount of time.

Have you checked the water level in the batts?

HTH

[hitthebricks]

The test was from the MK battery indicator and water levels are good in the batterys. Where is that tester on sale at? Do I need to disconnect the wires on the batterys to test it? HTB

[countryboy9799]

When I right clicked on that image and chose properties it came up from harborfreight.com

The make lower quality stuff but for occasional use it might not be a bad deal. If you are concerned you may want to take them back to were you bought them and see how they check out. My experience with TM batteries is that they dont last more than 2 or 3 years normally so your batts may just be normal.

On the flip side of it I got one from walmart, the neverstart brand and I am on my 5th. year but it is on its last I think, go figure.

Good luck

[HaywardBound]

countryboy is right, its at Harbor Freight Tools. There is a Store in Col. Heights, and one in St.Paul.

[castmaster]

does the auto pilot motor have any kind of little lights that stay on? i had trouble in the past with the charging indicator lights on my onboard charger draining tha batteries over extended periods, i have to disconnect the inline fuse to keep that from happening.

also, ifthe batteries sat dormant for an extended period, they may need to be charged and discharged a ferw times before they'll take a full charge again.

[hitthebricks]

I brought the batterys into Batterys Plus and had them tested, both are good. theres no indicator lights on the charger unless you press the test button, the trolling moter is unpluged and I can't find any thing else hooked up to it but it still discharging. How would I test to see if the onboard charger is giving a full charge before shutting off. HTB