Thread: No Power

A guy can sure learn a lot here! Even though this wasn't my issue, I learned a lot by reading the responses.

Originally Posted by CatFan

The reason it won't charge it is because the Coast Guard requires things that might be installed in a compartment with a fuel tank to be ignition protected. If the leads of the charger were touching each other and you plugged it in it might spark if it thought it was trying to charge a battery. To avoid that, the charger looks for a voltage on the leads which would indicate a battery before it turns on. A completely dead battery is indistinguishable from shorted leads to the charger. Once you get some voltage on the battery, the onboard sees that it is safe to turn on and it goes to work.

I understand all that ... but, would you trust a revived dead battery that's been sitting dead for months & then recharged ?? (see my comments in post #8 and critique what I said)

... cp

I agree with CrappiePappy on having the load test done before trusting it.

Originally Posted by CrappiePappy

Not sure I'd trust that battery, after it being discharged so low for so long, even if it did charge back up (or the charger indicated that it did). I'd be afraid I had only put a "surface charge" on it. I think I'd have it load tested, or just exchange it for a new one. Otherwise, I'd be sure and have a jumper cable in the boat ... or tools to switch the cables over to the 12V trolling motor battery, just as a precaution.

And in the future, I'd remove the batteries when the boat is put in storage for more than a month or so, and charge them once a month during the down time.

I may be looking at this from a worse case scenario point of view, and your battery may well be fine for years to come, but I'm just skeptical about batteries ... having experienced them fail at the most inopportune times.

... cp

Oh, there's no doubt the battery has been damaged, but it's hard to predict how badly. I've seen batteries that have sat for a long time take a charge and work for a couple of years. How much useful life it has (if any) depends on how big the battery is, what kind of load is demanded of it in use, how long it's actually been dead, what kind of temperature it was exposed to while dead, and a good healthy dose of luck.

I don't trust ANY battery to get me started, so I carry jumper cables in the boat all the time and the first time I notice electronics shutting off when I crank the outboard I replace the battery.

To me the most important battery in the boat is the one that gets you home. Your cranking battery has everything hooked to it (lights bilge pump livewell pumps and a lot of people run depth finders also). I try and run the biggest battery i can fit in the battery area. Like what was stated above never leave dock with out jumper cables.