Cranking battery problem- HELP!

[kaffik]

Hello all. I just bought a 2001 Skeeter with a yamaha V-Max 225 engine. Do lots of tournament fishing- and every time I go out my cranking battery has died early. I just bought a new one 2 months ago-and still the same thing happens. I am only running my live well and 2 Fish finders off of it. Its a new dual purpose, 31 group deep cell battery. If I am not using live well- only fish finders, the battery will last about 8 hours only. Add on the live well - and the battery dies after 2-3 hours. I have had the battery load tested 3 times by different people- it is fine ( only 2 months old). No one can figure out what is going on. I have a huge tournament this weekend- and do not want this happening again. Any ideas what could be draining it? I do not want to switch it to my deep cells- as they are running my 36v TM....and don't want that crapping out, as I troll most of the day. HELP!!
Thanks for any ideas you can provide.

 

[gm280]

Well there are a couple things you need to figure out. First, is this the same battery your engine is being cranked with? Second, If you are not getting but a few hours out of it then you have more current drain then your privy to. I would first remove the power to both Fish Finders and the live well. And see if the battery fizzes out without anything attached. Obviously it shouldn't. Then attach just one circuit at a time to see how long the battery powers it. And do the same thing with the second circuit as well and so on until you see which circuit is the culprit. Could be you have more current being drained somewhere in one of those three circuits. If you know how to use a DVM (Digital Volt Meter) you could set it up to read current and find out quickly if one of the three circuits is drawing more then it should. Once you find the larger then thought current drain, it is time to trace out the wiring and fix that problem.

If all else fails, you could buy a deep cycle battery to use and not a dual purpose one. BUT, you have to fully charge the batteries and verify your charging system is doing that as well. JMHO

 

[metriccrescentwrench]

It doesn't sound like the engine's charging system is working. Along those lines - does the tachometer seem to be working properly (if not it's a good indication there's a problem with the rectifiers). Do you have a voltmeter so you can monitor battery condition?

 

[MH Hawker]

yes i would test the charging system first

 

[s.hadley81]

deleted

 

[s.hadley81]

An easy way to test for a drain would be to get mutlitmeter and set it to amps then disconnect your negative battery cable, put one lead to the negative cable and one to the negative battery post and see what you get. I would think if you are indeed only running the live well and 2 finders than I would maybe say around 5 amps is what you should see as your live well should be around 2.5amp and each finder should maybe be 1amp. If you see a large draw disconnect each accessory one at a time to se what is drawing too much or if something else is drawing when it shouldn't be. To check your charging system set the multimeter to volts dc and with the battery hooked up and motor running you should get around 13 to 14v. Best of luck you on your problem and tourney!

 

[s.hadley81]

Also figured I'd mention that if your charging system is not up to par the rectifier can actually drain your battery as well.