Boat battery issues

DAN El motor suele dar carga a la batería, lo raro es que no tenga capacidad para mantenerse, puede ser debido a
1 tiene una fuga de carga o grieta o cable pelado
2 El cableado este sulfatado tendrías que revisarlo
3 ¿cuantas veces las recargado y añadido agua destilada? cuantas mas veces hagas esta acción va
perdiendo su capacidad.
4 el motor no carga la batería.

Una bateria de 70 A (amperios), es mas que suficiente para arrancar el motor y mantenerse durante un par de años en perfecto estado.
Si el motor es antiguo mercury 90 ¿es tres cilindros o dos), deberías cambiarlo por uno mas moderno 2 t ecotec evinrude o inyección directa
de Tohatsu, consumen poco casi nada, corren mas y tienen mas potencia que los de 4T.

I would say you should be safe, with a good battery( you will know in five days), going with once a month.

As in, hook it up over night and leave it for twelve hours and your battery should last a long time

Dan, the one you purchased has a very good reputation and will not fry your battery or blow up a gel cell if you buy one in the future. Remember that the boat is a fuel filled bomb sitting next to your house, I would sleep better the night before a trip knowing I'm using a top end device instead of a cheep charger that could have a switch bumped to a high setting. At some point if that is a wet cell battery you need to check the electrolyte/water level to avoid a dry cell that will fry. Don't worry about the charger getting warm it has a thermo overload, do make sure the battery box is vented as hydrogen and oxygen produced by over charging is explosive. Always turn the battery disconnect switch to off when the boat is not being used. Find a skinny dive buddy and have him check what type of battery in the boat and that the connections are clean and sound. A boat is not a car you can step out of and walk, calling a Boat Tow service may delay the well being of capt and crew in a emergency, and I getting to like you guys, so be safe.:D;)

Cheers, Don

¿Tienes instalado este desconectador de baterias?, cuando no usas la barca

BEP MARINE
Desconectador baterías 1p, ON/OFF, 600A

that battery tender is fine, I used the same unit on my boat until I went with the onboard unit which is permanently mounted and wired. I dont know if you have room in your boat but like Don said, its always advised to have 2 banks of batteries one for starting and one for the house battery with a switch to isolate both bank or run both at the same time

Quote from Dan

I don't have room for another battery unless it's going to sit on the deck. I have a stereo, GPS/depth finder, and an electric water pump. I mostly use the handheld GPS and hardly ever use the stereo. Is a 2nd battery really necessary in my case?

you dont need another battery. Just make sure when your boat is off, everything shuts off. You should carry a rope to pull start your engine just incase your batteries ever dies.

Quote from Dan

Thanks for the suggestions. There's a pull cord in a little pouch inside the motor cowling. What I do need to do is learn where to connect it.

You will learn quickly once you are drifting to Bahamas

Quote from Dan

I do have an anchor and the other end of the rope gets tied to the boat right?

See there you go;)....the anchor gets tied to the end of a small red eye buoy so you can ditch it in a shark battle
or blackout .:@

You don't need two till the next boat.... but don't forget to turn off the stereo, disco ball and blender.:D

Cheers, Don

That motor is easy to start with the pull cord. Easier if there is two people; one pulling the cord and the other cranking the start. I can't remember how many times I did the count: "uno, dos, AHORA!"

You should practice it BEFORE heading out.

Quote from Marco

You should practice it BEFORE heading out.

Yes, as long as one is not the "puller".:D

That 90hp engine is not that hard to pull start.

ive pull started a 60 and 200. 60 was cake so a 90 shouldnt be bad at all. the 200 sucked luckily we realized someone had bumped the emergency shut off switch, rectified that and went back to electric start.

Dan on your boat one battery should be fine. In the future if you have to replace it just do so with a gel battery. And again just remember to shut everything down, or install a switch. But that isn't really necessary with only one battery it would just allow you to shut everything off by flipping it. Its good redundancy I guess having the switch, I know I try to shut everything down, but I also flip the switch off.