From fully charged battery to dead in 20 minutes!

[ronsealdeath]

Hello there,

I have a 1977 55hp Evinrude on a 14ft speedboat that has no charging system owing to a busted rectifier. All runs great though until yesterday when we took it for a burn across the bay for about 20 mins at 75% throttle, turned around and shut off to put some fuel in. When we turned the key there was nothing, it turned out the battery was completely dead. It was fully charged before we left via a 240v charger. Never had any probs before and battery is 41ah. We have no other electricals connected apart from a tacho which was removed for yesterdays run so the wires were just hanging under the dash.

What would have discharged an entire 41ah battery in 25 mins? Could my starter have been going the whole time if the key didnt come back to the first click properly? I cant check it at the moment as the weather is too bad but its really bugging me!

The inshore lifeboat had to come out and get us :facepalm: Thanks to the RNLI !

Al

 

[Silvertip]

Re: From fully charged battery to dead in 20 minutes!

If you made a highspeed run with the starter engaged you would have heard the racket as mechanical parts were hurled through the engine cover. Just because the battery was fully charged does not mean it is capable of holding a charge. In other words, the battery is headed for battery heaven. But before you buy a new one, charge it, then dash to an auto store and have it load tested. Only a load test will determine if it is capable of holding a charge.

 

[ronsealdeath]

Re: From fully charged battery to dead in 20 minutes!

Hi, I think you must be right. Will give it a charge and see if I can get it load tested. The only reason I mention the starter is that last year when I fired it up on the trailer the key must have got stuck and it was spinning the starter motor but not with it engaged to the teeth on the flywheel. DOnt know why it did it but it got very hot! A bit of grease on the mecahnism and it hasnt done it since. Just wondering if something similar to that may of happened? No way to know until I get everything checked out but wondering if anyone has had a similar issue?

A new battery is obviously a good move anyway bu I now feel like a spare battery would also be a good idea. Can I just keepone charged up in the boat ready to be hooked up if necessary? Or should I use a switch etc...?

Cheers for the help
Al

 

[j_martin]

Re: From fully charged battery to dead in 20 minutes!

A battery will self discharge (local galvanic action) in a month or two, so you have to charge it up from time to time even if you don't use it.

 

[Navigator_Victory]

Re: From fully charged battery to dead in 20 minutes!

Hi, I think you must be right. Will give it a charge and see if I can get it load tested. The only reason I mention the starter is that last year when I fired it up on the trailer the key must have got stuck and it was spinning the starter motor but not with it engaged to the teeth on the flywheel. DOnt know why it did it but it got very hot! A bit of grease on the mecahnism and it hasnt done it since. Just wondering if something similar to that may of happened? No way to know until I get everything checked out but wondering if anyone has had a similar issue?

A new battery is obviously a good move anyway bu I now feel like a spare battery would also be a good idea. Can I just keepone charged up in the boat ready to be hooked up if necessary? Or should I use a switch etc...?

Cheers for the help
Al

I have had this happen.....it would just sit there and spin if you let it but,,,,,,I could hear it spinning...IE something did not sound right.....teeth were just below the flywheel so they did not engage

 

[ronsealdeath]

Re: From fully charged battery to dead in 20 minutes!

Hi J_Martin, I do keep it charged and always give it a full charge before an outing which is the curious thing here.

Interesting to here about the starter spinning as well. Just got back from honeymoon so going to investigate it further now. Anyone got any ideas on the best way to avoid this situation in the future in terms of having a spare battery or 2 battery hook up? I dont really have room for a spare outboard.

Cheers for the replies
Al

 

[ronsealdeath]

Re: From fully charged battery to dead in 20 minutes!

OK major egg on my face here ;

Just checked battery, charge at 12.6v. Went to charge it and charger said ready! Ok, battery had enough juice to get things going so I had a look at the boat and realised that whilst removing my tacho I had left bare wires hanging and guess what, +ve and -ve wires were touching nicely together. Checked the motors inline fuse and sure enough it was blown. Oh dear, all my fault and nothing to do with phantom starter motors etc...

Just goes to show its the simple things that leave you stranded in the middle of the sea!

Yours

Stupid of Wales