What Battery Charger ?

[JonL]

I have a very simple set up ( suits my very simple brain ), one battery a new Halfords Lesuire 75 that is used to start a new 15hp Mariner outboard. Additional equipment is also simple consists of three lights, a very small water pump and a radio all off the same battery.

Use the boat for day trips, with the engine running for about 3 or 4 hours, generally switched off when double locking.

 

I know the charge back rate from outboards are not great and I'm concerned that overtime i will eventually fall behind on recharging that battery.

Two questions:-

1.What is the best battery charger to use on a Lesuire battery ? - I'm happy to take the battery home every couple of months and charge it.

2. Is there a simple ( cheap and easy to wire ! ) battery monitor that I can use to tell me when the battery is getting tired ?

 

Thanks in advance as always

 

Jon

[GSer]

I have a very simple set up ( suits my very simple brain ), one battery a new Halfords Lesuire 75 that is used to start a new 15hp Mariner outboard. Additional equipment is also simple consists of three lights, a very small water pump and a radio all off the same battery.

Use the boat for day trips, with the engine running for about 3 or 4 hours, generally switched off when double locking.

 

I know the charge back rate from outboards are not great and I'm concerned that overtime i will eventually fall behind on recharging that battery.

Two questions:-

1.What is the best battery charger to use on a Lesuire battery ? - I'm happy to take the battery home every couple of months and charge it.

2. Is there a simple ( cheap and easy to wire ! ) battery monitor that I can use to tell me when the battery is getting tired ?

 

Thanks in advance as always

 

Jon

 

 

A small solar panel might help reduce the time spent on the charger, to test the state of charge a hydrometer is cheap and useful, combine that with a voltmeter that should give you a reasonable idea on the batteries state of charge.

 

Other more knowledgable peeps will be along in a minute to shoot me down

 

Paul

[WotEver]

What Paul said

 

If your boat spends more time being moored up than it does cruising, like mine, then a solar panel will probably be sufficient to keep it permnanently topped up.

 

And an accurate Hydrometer is an excellent method o checking SOC.

 

Tony

[RLWP]

What Paul said

 

If your boat spends more time being moored up than it does cruising, like mine, then a solar panel will probably be sufficient to keep it permnanently topped up.

 

And an accurate Hydrometer is an excellent method o checking SOC.

 

Tony

 

I have done a brief search in the past on this. I know we have covered the "megawatt" solar panel systems for liveaboards, but I couldn't find a simple setup for battery maintenance.

 

For instance, we have a starter battery and three domestic batteries. Do I need one solar panel or two, how big, what type, can they be mounted to be effective, reasonably theft proof and removable for cruising? And so on....

 

Richard

[paulcatchpole]

I have done a brief search in the past on this. I know we have covered the "megawatt" solar panel systems for liveaboards, but I couldn't find a simple setup for battery maintenance.

 

For instance, we have a starter battery and three domestic batteries. Do I need one solar panel or two, how big, what type, can they be mounted to be effective, reasonably theft proof and removable for cruising? And so on....

 

Richard

 

Hey Richard...

 

Parallel the banks using a decent battery isolator between the positives (presuming negs are linked anyway) when you leave the boat, or overnight? That's what we used to have before we bought a Smartbank, and wanted to charge the domestics when the alternator was attached to the start battery...

 

How does your alternator currently charge the domestics? (Or starter, if it's attached to the domestics)

 

As for size of panels, no idea, but not big... I know you don't like stuff on the roof when cruising, but they wouldn't have to be too big for just maintenance, and could be permanently fixed? Weld/bolt a few brackets (pieces of 1" box?) onto the roof, and attach panel frames to that? Biggest of my concerns would be someone throwing rocks at them for fun, but ask Smelly, 'cause he's got a permanent setup I think?

 

PC

[Chris Pink]

2. Is there a simple ( cheap and easy to wire ! ) battery monitor that I can use to tell me when the battery is getting tired ?

 

A multimeter is an very useful tool and can be used to tell you the state of charge of your batteries. A fairly basic one from Maplin won't cost too much.

[RLWP]

Hey Richard...

 

Parallel the banks using a decent battery isolator between the positives (presuming negs are linked anyway) when you leave the boat, or overnight? That's what we used to have before we bought a Smartbank, and wanted to charge the domestics when the alternator was attached to the start battery...

 

How does your alternator currently charge the domestics? (Or starter, if it's attached to the domestics)

 

As for size of panels, no idea, but not big... I know you don't like stuff on the roof when cruising, but they wouldn't have to be too big for just maintenance, and could be permanently fixed? Weld/bolt a few brackets (pieces of 1" box?) onto the roof, and attach panel frames to that? Biggest of my concerns would be someone throwing rocks at them for fun, but ask Smelly, 'cause he's got a permanent setup I think?

 

PC

 

How does the alternator charge the domestics? Let's see.

 

There's an alternator with wires on the back, then there's a rat's nest of wires and connectors, some with spiral wrapping under the oil and grot, then there's a funny little black box on the front bulkhead, after that I think faeries carry the electric to the batteries in foxglove flowers, but somehow it all works.

 

I'd rather not link the domestics and starter because:

1. If I forget to turn off the fridge or water pumps it'll flatten the starter
   
2. If the bilge pump works overtime because of rain it'll flatten the domestics too and I won't have my emergency power source
   

 

Anyone got any experience of this?

 

Richard

[nb Innisfree]

How does the alternator charge the domestics? Let's see.

 

There's an alternator with wires on the back, then there's a rat's nest of wires and connectors, some with spiral wrapping under the oil and grot, then there's a funny little black box on the front bulkhead, after that I think faeries carry the electric to the batteries in foxglove flowers, but somehow it all works.

 

I'd rather not link the domestics and starter because:

1. If I forget to turn off the fridge or water pumps it'll flatten the starter
   
2. If the bilge pump works overtime because of rain it'll flatten the domestics too and I won't have my emergency power source
   

 

Anyone got any experience of this?

 

Richard

 

No 'cos our domestics and starter are separate

Edited June 8, 2010 by nb Innisfree

[RLWP]

No 'cos our domestics and starter are separate

My domestics and starter are also separate, that's the point of me asking the question in the first place

 

Richard

[paulcatchpole]

How does the alternator charge the domestics? Let's see.

 

There's an alternator with wires on the back, then there's a rat's nest of wires and connectors, some with spiral wrapping under the oil and grot, then there's a funny little black box on the front bulkhead, after that I think faeries carry the electric to the batteries in foxglove flowers, but somehow it all works.

 

I'd rather not link the domestics and starter because:

1. If I forget to turn off the fridge or water pumps it'll flatten the starter
   
2. If the bilge pump works overtime because of rain it'll flatten the domestics too and I won't have my emergency power source
   

 

Anyone got any experience of this?

 

Richard

 

A fair point, Mr Richard!

 

As aforementioned, we bought a smartbank to get around that one... It'll disconnect the starter battery from the domestics if the lot starts getting discharged, to protect starting ability.

 

If you don't want to link them at all, then I think you're looking at two panels, 'cause diodes aren't exactly a brilliant idea due to the waste of potential via the voltdrop!

 

On the other hand, I'd rather the bilge pump flattened the batteries than the boat sank, and the water pumps surely shouldn't be running when there's not a tap in use? Fair point on the fridge though...

 

S*d the cash Richard, buy a Smartgauge+Smartbank, it'll save you money on the batteries over a replacement period, for just knowing you're above the 50% mark... And solve this problem! I, honestly (and I don't love Gibbo that much... I'm saving that for Carl, sorry Creamcheese...) think it's the most useful battery-related gadget ever. Possibly apart from an actually working alternator when that didn't work to start with....

 

GadgetGadget.

 

PC

 

PS: I'll even fit it for you, and do anyfink electrical you like, gratis...

Edited June 8, 2010 by paulcatchpole

[blodger]

A fair point, Mr Richard!

 

As aforementioned, we bought a smartbank to get around that one... It'll disconnect the starter battery from the domestics if the lot starts getting discharged, to protect starting ability.

 

If you don't want to link them at all, then I think you're looking at two panels, 'cause diodes aren't exactly a brilliant idea due to the waste of potential via the voltdrop!

On the other hand, I'd rather the bilge pump flattened the batteries than the boat sank, and the water pumps surely shouldn't be running when there's not a tap in use? Fair point on the fridge though...

 

S*d the cash Richard, buy a Smartgauge+Smartbank, it'll save you money on the batteries over a replacement period, for just knowing you're above the 50% mark... And solve this problem! I, honestly (and I don't love Gibbo that much... I'm saving that for Carl, sorry Creamcheese...) think it's the most useful battery-related gadget ever. Possibly apart from an actually working alternator when that didn't work to start with....

 

GadgetGadget.

 

PC

 

PS: I'll even fit it for you, and do anyfink electrical you like, gratis...

 

Where the currents are relatively low the 0.3v volt drop across diodes does not dissipate that much. My two solar panels (55w) are aging and they do better without the solar controller and switched diode split charging to each of the battery banks, likewise the wind charger buit then, I am carrying 15 x 110 amphr batteries around and maintaining them at 12.8v, average age 6.5/7 years.

[paulcatchpole]

Where the currents are relatively low the 0.3v volt drop across diodes does not dissipate that much. My two solar panels (55w) are aging and they do better without the solar controller and switched diode split charging to each of the battery banks, likewise the wind charger buit then, I am carrying 15 x 110 amphr batteries around and maintaining them at 12.8v, average age 6.5/7 years.

 

0.3vdrop?

 

What diodes are those? What forward current at that bias?

 

PC

[blodger]

Shotky (or however you spell it) 30/40 amp diodes on Ebay for about 2.00 if you offer rather than 'buy now' from Chezchelavkia (likewise)

[WotEver]

Shotky (or however you spell it) 30/40 amp diodes on Ebay for about 2.00 if you offer rather than 'buy now' from Chezchelavkia (likewise)

Schottky and Czech Republic ;-)

 

Ebay linky for above reference.

 

Tony

[blodger]

Schottky and Czech Republic ;-)

 

Ebay linky for above reference.

 

Tony

Thanks for the link. Have you used them? They seem OK. I have only had one fail through using it without a heatsink to isolate a dynamo from battery when testing the former. I havet not used heat sinks yet for solar or wind charger application because they do not seem to heat up at all in that use/current range although I will when I finalise 'my solutions' after experimenting.

[WotEver]

Thanks for the link. Have you used them?

Nope. But they would appear suitable for the purpose.

 

Tony

[paulcatchpole]

My domestics and starter are also separate, that's the point of me asking the question in the first place

 

Richard

 

So, Uncle Richard, have you decided what to do?

 

PC