Charging starter battery from leisure battery charger.

[Boat&Bikes]

Hi all, lovely day.

My starter battery is dead. My 4 leisure ones are on hook up charged by a inverter charger. 70 amp charger.I've a feeling my starter battery is on the way out, but would like to give it a good charge before i replace. Would it be wrong to run jump leads from the leisure to starter batteries and charge like this for a day?

Cheers,

Ian.

[nicknorman]

That will be fine from the point of view of the batteries. Just bear in mind that attaching jump leads to batteries is potentially a bit dangerous. If the positive lead were to come off the starter battery and touch the hull, you could generate a massive short circuit. You might then for example try to grasp the lead to pull it away from the hull or battery, to find that not only is it welded in situ but also it is red hot and burning through your hand.

[Alan de Enfield]

No problem.

Just check the water levels, look for any distortion in the battery case and feel for any heat - if your starter battery is shorting internally you should get one of those symptoms. If the battery is just 'knackered' than the charge you put in will only be short-term,

Remember to disconnect the starter from your leisure bank as, if there is a problem, it could flatten your leisure bank as well.

[Boat&Bikes]

Thanks both. Starter battery looks ok appearance wise. Can't top up its sealed. Seeing what Nick has said I think il play safe and take my car type charger to boat and attach to just the starter battery. My inverter charger has provision to also charge a starter battery, it's was never connected and I've never felt the need as I cruise lots and starter has always behaved. Due to my mother being ill recently I've not ran the boat engine for a few weeks so it's not been charged. Should add it is 10 years old so...thanks again people.

[Robbo]

1 hour ago, ianali said:

Hi all, lovely day.

My starter battery is dead. My 4 leisure ones are on hook up charged by a inverter charger. 70 amp charger.I've a feeling my starter battery is on the way out, but would like to give it a good charge before i replace. Would it be wrong to run jump leads from the leisure to starter batteries and charge like this for a day?

Thing to note; If the charger/inverter is a Victron it has an additional connection purely for keeping your starter battery charged.

[nicknorman]

29 minutes ago, ianali said:

Thanks both. Starter battery looks ok appearance wise. Can't top up its sealed. Seeing what Nick has said I think il play safe and take my car type charger to boat and attach to just the starter battery. My inverter charger has provision to also charge a starter battery, it's was never connected and I've never felt the need as I cruise lots and starter has always behaved. Due to my mother being ill recently I've not ran the boat engine for a few weeks so it's not been charged. Should add it is 10 years old so...thanks again people.

A starter battery in good condition should last many months before self-discharging to the point of not being able to start the engine. So as you surmise, time for a new starter battery!

[Robbo]

Dodgy leads to/from the starter battery to the starter/engine and isolation switch can all look like a dodgy battery so make sure these are okay before replacing the battery.

[WotEver]

12 minutes ago, Robbo said:

Dodgy leads to/from the starter battery to the starter/engine and isolation switch can all look like a dodgy battery so make sure these are okay before replacing the battery.

Good advice, this

[Alan de Enfield]

16 minutes ago, Robbo said:

Thing to note; If the charger/inverter is a Victron it has an additional connection purely for keeping your starter battery charged.

 

44 minutes ago, ianali said:

My inverter charger has provision to also charge a starter battery, it's was never connected and I've never felt the need as I cruise lots and starter has always behaved

 

[Chewbacka]

1 hour ago, Robbo said:

Dodgy leads to/from the starter battery to the starter/engine and isolation switch can all look like a dodgy battery so make sure these are okay before replacing the battery.

Good advice, but I'm inclined to guess a 10 year old battery on a very cold morning is never going to do well....................

[Boat&Bikes]

1 hour ago, Chewbacka said:

Good advice, but I'm inclined to guess a 10 year old battery on a very cold morning is never going to do well....................

Yes I've been waiting for it to die. I will though check over the connections. Pretty sure all is well but you never know huh. 

[WotEver]

2 hours ago, Chewbacka said:

Good advice, but I'm inclined to guess a 10 year old battery on a very cold morning is never going to do well....................

My relatively new car battery caused the car’s computer to give a little beep when starting it over the last couple of days. The CPU was just about to say “battery problem” when it was pre-empted by the engine starting each time. 

[cuthound]

5 hours ago, ianali said:

Should add it is 10 years old so...thanks again people.

TEn years is an exceptional life for a sealed battery, even if it an AGM battery.

It owes you nothing. Replace it.

Even if you do manage to recharge it,  it is very much on borrowed time.

[Boat&Bikes]

1 hour ago, cuthound said:

TEn years is an exceptional life for a sealed battery, even if it an AGM battery.

It owes you nothing. Replace it.

Even if you do manage to recharge it,  it is very much on borrowed time.

We are all on borrowed time. I agree and will very likely replace, just thought a good charge might be worth a shot. What's to lose? 

Ian.

[Chewbacka]

1 hour ago, ianali said:

We are all on borrowed time. I agree and will very likely replace, just thought a good charge might be worth a shot. What's to lose? 

Ian.

Well as it is a bit warmer now, your battery may recover enough, but when it turns cold again it will probably fail again, so you may manage to put off replacing, BUT if the ability to start is important, then ignore the warnings from your battery at your peril.

[Boat&Bikes]

9 minutes ago, Chewbacka said:

Well as it is a bit warmer now, your battery may recover enough, but when it turns cold again it will probably fail again, so you may manage to put off replacing, BUT if the ability to start is important, then ignore the warnings from your battery at your peril.

Boats tucked up on shore power till March. We like to have the odd night or two out but if she won't start it won't be a big problem. Il charge it and see how it goes then no doubt replace before we go out in March for the summer. Thanks to all for their help.

Ian.