Help, i'm running out of budget and need a decent charger

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forrestmichael

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Help, i\'m running out of budget and need a decent charger

Hi, my batteries are dead, i'm on a dry dock while i do an ever expanding amount of work and need to maintain my two new 110 amp domestic batteries and a 80 amp engine battery.

I originally thought about just buying a halfords car charger but have read these are no good for deep cycle battery charging, once the boat is back in the water this autumn or more likely next spring i'll be relying on solar and the engine to top up the batteries.

What would people recommend as a cheap but reliable solution, i don't want to ruin my batteries but don't want to spend more than £100.

Also, if I went for the halfords option where could i clip the bulldog clips for charging, would I need to do each battery bank direct or could i rig something to the battery switch and select both.

Hopefully someone has had a similar dilemma

thanks

mike /forums/images/graemlins/frown.gif
 
Re: Help, i\'m running out of budget and need a decent charger

If they are flat, any charger ASAP is a lot better than nothing.
A simple car charger will take a long time to fully charge those batteries but if they are gel or agm batteries it would be best to check the manufacturers website.
Do not leave a cheap charger connected long term. Remove it when the battery gets up to about 14.5V for a wet lead acid battery.
The Clarke automatic chargers (Machine Mart) aren't bad for workshop use, but will not start unless there is some charge in the battery.
I think £100 is a tight budget for a 2 or 3 output multi stage charger, but I await enlightenment too!
A couple of small solar panels for keeping them topped up is pretty cost effective.
Personally I mostly use a Lab power supply, 14V to charge, 13.2V to float. But some lab psu's will die if you apply 12V to the output with the mains switched off!
Hope that helps a bit!
 
Re: Help, i\'m running out of budget and need a decent charger

The problem with some of the current Halford budget chargers is that they are designed to switch to maintenance mode when they hit 13.8 volts and leisure batteries do like a bit of extra Ooomph to equalize. ie 14.7 volts. Some Halfords take an eternity to bring a leisure battery from dead as they insist on this maintenance mode and keep switching off.

I believe Sterling do a charger for around £100 and brother in law found it great on his Mobo. Although it is fully protected it runs off a timer and goes on for a few hours a couple of times a week and keeps his 2 X 110 Ahr batteries full and ready to go. This was never the case with the budget Halford which seem more suitable for the lower capacity starting batteries.
 
Re: Help, i\'m running out of budget and need a decent charger

Thanks everyone for replies so far, i did spot the Sterlin charger on force 4 and thought it might do the trick, trouble is i got confused because they all had different amp ratings, the cheapest is 10 amps, what do these ratings mean? Will the batteries just take longer to charge in which case i'm not too worried?

I guess if I go for this Sterling charger i will need to install a cockpit socket for shore power too...
 
Re: Help, i\'m running out of budget and need a decent charger

10 amps is its output and it will struggle to keep your banks topped up. Also it will only do one battery at a time.

You need to look at a 3 output multi stage charger of at least 25, preferrably 40 amps. Between £150 and £200. You then need a reliable safe shorepower sytem to hook up to the mains - more dosh. Alternatively consider a Dolphin all in one charger and shorepower 40 amp is about £400. See Merlin wwww.power-store.com Barden or Mastervolt are other suppliers.

Recognise that what you want to do is not cheap.
 
Re: Help, i\'m running out of budget and need a decent charger

Michael

Am I right in thinking you have a Contessa 26? If so, why have you got such a huge battery bank? This is more suitable for a 35 footer running fridge, loads of nav equipment, interior lights etc. On a boat your size one of the 110 amp would be plenty plus your engine start. Unlikely you would be able to charge them fully with your engine alternator as this is likely to be less than 35 amps. There is no benefit in having more capacity than you need, nor have charging capacity for.

An appropriate set up would be two separate banks, the 85 for engine start and 110 for domestic. Have a split charging arrangement, preferrably with a VSR or diode plus a switch for paralleling so that you can start the engine from both batteries if needed. Once the batteries are fully charged and they do need a high powered charger, your alternator plus a solar panel on the service battery should keep them topped up.

If the boat is out of the water, take the batteries to a battery shop that has a multi stage charger, get them fully charged. Then an automotive 6-10 amps charger will keep them up, but only one at a time.

Hope this helps
 
Re: Help, i\'m running out of budget and need a decent charger

When I was in Halfords a few days ago I noticed that they had a new battery charger on sale, not yet on the website, fully automatic with umpteen stages in the charging sequence including a desulphating stage and ending with a maintenance charge so it could be left on 24/7. Just under £50 IIRC. It might be worth checking out.

I might have bought one for myself but I had just filled the car with diesel! /forums/images/graemlins/frown.gif
 
Re: Help, i\'m running out of budget and need a decent charger

Hi Tranona, yes I have a Contessa 26 and agree these batteries seem excessive but they are what have been fitted, I have a new Yanmar 1GM engine with 35Amp alternator.

I'm planning a lot of cruising, i have a tropicool coolbox on board, bilge pump, instruments, lights, i-pod dock, and i'm sure some other stuff too. I'd like to think I have enough power and as I have the batteries why not use them? Would a 110 amp be enough alone to run all of these things?

Again thanks for you help

Mike
 
Re: Help, i\'m running out of budget and need a decent charger

Yes, Michael, but you won't be able to charge them with a 1GM and if they are not fully charged will not last.

Have a look at some of the basic principles of electricity. consumption is in watts, amps is calculated by dividing by volts. So a 25w bulb, for example in a tricolour will use about 2 amps an hour (25/2). So in an average summer night it will use 16 amps. Your 110 AH battery wil have a usable capacity of around 50% or 55AH. So four consumers like this will take your battery down in one night. To recharge, your 1GM at 35 amps will take 1.5 hours minimum to bring it back up, assuming no losses. At cruising revs 2400, it produces 4KW, so 10% of your engine power is taken by your alternator (35*12 = 410 watts) and will take nearly 2 hours to bring up the charge (ignoring losses and the need to replace the power you took out of the battery to start the engine).

Therefore the first thing on a small boat like yours is to estimate your average consumption between charges. Nav equipment is low consuming, but coolboxes are greedy! So if you used your full capacity of your two service batteries every day you would have to run the engine about 4-5 hours a day!

So, what to do? The first thing is to make maximum use of what you have. This means splitting the two banks and having a split charge circuit using a diode or a VSR. This will direct the charge to the battery that needs it most, usually the engine start after starting the engine. Then run all your services off the service battery, but use a switching mechanism so that you can parallel the batteries to start the engine if that battery fails, or switch on your nav lights if the service battery is dead.

Then you can look at ways of reducing consumption (such as LED lights) or increasing charging capacity by such things as a solar panel or a smart charging system. Of course all these things cost money because you are fighting the laws of electricity.

First thing I would do is ditch one of the 110AH batteries and invest in a good split charging system. If you leave the boat all week after a weekend sail a solar panel is a good way of topping up for next weekend. Big consumers can also use shorepower battery chargers, but to be honest these are expensive and OTT on a boat such as yours.

Sorry if this sounds like a lecture, but been there! Suggest you read Nigel Calders book on the subject or James Hartop of Merlin who often writes in the mags. Other suppliers such as Sterling, Barden, Mastervolt etc also produce good information.
 
Re: Help, i\'m running out of budget and need a decent charger

To be a bit pedantic /forums/images/graemlins/frown.gif but if you are going to deliver lectures like that /forums/images/graemlins/grin.gif you've got to get these things right. The two sentences that read:
So a 25w bulb, for example in a tricolour will use about 2 amps an hour (25/2). So in an average summer night it will use 16 amps
should read:
"So a 25w bulb, for example in a tricolour, will use about 2 amps (25/12). So in an average summer night it will use 16 ampere hours (Ah)"
 
Re: Help, i\'m running out of budget and need a decent charger

[ QUOTE ]
The problem with some of the current Halford budget chargers is that they are designed to switch to maintenance mode when they hit 13.8 volts and leisure batteries do like a bit of extra Ooomph to equalize. ie 14.7 volts. Some Halfords take an eternity to bring a leisure battery from dead as they insist on this maintenance mode and keep switching off.


[/ QUOTE ]

I wondered why mine did that, it stays at home for the car now!
 
Re: Help, i\'m running out of budget and need a decent charger

There has been a whole lot of waffle said on this subject.

The large 2X110 AH batteries are perhaps an overkill but now they are fitted you might as well leave them there.

Current times amps taken from a battery must be replaced. A 35 amp alternator will do it but it may take longer if they are all flat. With a standard 14v regulator on the alternator having a larger battery bank means that more current is pushed into the batteries for longer. Initially the alternator capacity will be limiting factor but after a while the voltage on the batteries rises so the current falls but if you have twice as much battery then the current at all stages will be twice as much as the current declines.

So Michael don't be too put off by the perfectionists. Your system will be OK but you might want to ditch the cooler in favour of a proper compressor fridge.

Now as for charging the batteries. Any kind of battery needs current to recharge. The problem lies in getting the current to stop when they have had enough. So if you can estimate how flat the batteries are you can simply replace the AHs required plus about 25%.

So if you reckon your 110 s are pretty low then stick 110 AHs into them. How? you will need an amp meter. A good digital voltmeter will have a 20 amp range. Any charger you have will put current in if can maintain more than 14 volts under load. If the charger can't maintain 14 volts then the current usually falls until the voltage is high enough. So the amp meter will show the outcome.

You could use a simple plug pack or similar power supply for electronic gadgets that you may have at home. You want one that has a transformer ie is heavy. (An electronic switch mode type is light weight and regulated so probably no good.) The power supply needs to be rated at at least 13 volts. Connect it up via your multimeter to confirm current into the battery. Even if the current is low like .25 amp this will be usefull. You might have to do the batteries consecutively.

You might want to take the batteries home so you can leave the charger on for days on end. Monitor the temperature of the power supply and don't use if it gets too hot. If current is too much for the power supply rating you can fit a resistor to limit current like about 1 ohm. Or better fit diodes 3 into the +ve lead and so feed all 3 batteries at once.

If the current is low like less than an amp then overcharge is not a problem as the battery will happily just soak it up. Just like with a small solar panel without a regulator.

Fancy battery chargers are designed for dummies to fit and forget but if you are prepared to monitor current and turn off manually then any form of charging is fine. (after all smart chargers have only been around for a few years. How do you think we managed before? good luck olewill
 
Re: Help, i\'m running out of budget and need a decent charger

[ QUOTE ]
Current times amps taken from a battery must be replaced

[/ QUOTE ] I think that should read :
Current (amps) times hours taken from the battery must be replaced
 
Re: Help, i\'m running out of budget and need a decent charger

[ QUOTE ]
(after all smart chargers have only been around for a few years. How do you think we managed before?

[/ QUOTE ]

Do you mind!, we were designing and building smart chargers back in 1984, it was just at the time the media thought Constavolt was the ideal.

All the chap needs is a cheap unregulated charger around 15amp rms, we can supply a little controller to go in the supply. This will allow the charger to charge up to 14.4 volt, then turn of the mains supply. It then turns back on to provide charge pulses, time period depends on recharge state. Can be left on 24/7, helps remove / prevent sulphation and provides fully charged batteries. Charge each battery on it's own to start with, then connect them as a bank, charger will be happy acting as a maintanence charge then. Problem is that it's to simple for modern times.

Brian
 
Re: Help, i\'m running out of budget and need a decent charger

Thanks everyone for your comments, i will try and limit my power consumption, i've just bought the cool-box so i'm stuck with that i'm afraid, it's a very efficient one though.

Solar panel seems a must, especially as my boat will be left all week, it'd be useful for making sure the bilge pump has enough juice if nothing else.

Thanks again

Mike
 
Re: Help, i\'m running out of budget and need a decent charger

Fancy battery chargers are designed for dummies to fit and forget but if you are prepared to monitor current and turn off manually then any form of charging is fine. (after all smart chargers have only been around for a few years. How do you think we managed before? good luck olewill

**************************************************

I don t think we had the fridges and icemakers in those days calling for 200+amp Hrs on a 26 ft Contessa.

Seems a bit much to expect the poor fellow to get a hernia getting 2 X 110 's out of the cabin lockers and ashore then over half a mile of pontoons Blimey Olwill thats as bad as trecking from the far end of the East Fremantle to the Clubhouse!! at least there are a few pretty live aboards to chat up en route....

Now folk want it all to happen in the allotted time and so a cheap auto charger is not always best as if left on for the week can do more harm than good hence the multistage becoming more popular as they can whop a decent charge into the batteries while we enjoy a few post sailing sundowners.

One answer is to put the elcheepo chargers on a timer to reduce the boiling time.

I was honestly surprised at the difference the cheap Sterling charger made to brother in laws life..No longer the threat of divorce due to fridge and hairtong restrictions and batteries always sitting at 12.6 volts at rest when they go for a trip on the Thames. The funny thing is that just like watching a boiling kettle you never seem to catch it on Equalise mode however there is no doubt it is doing a good job. This means fewer calls to my help line in Scotland, so we are all happy.

/forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
 
Re: Help, i\'m running out of budget and need a decent charger

Sorry for the slip in terminology, but does not affect the advice I was trying to give. Battery capacity should be balanced against demand and charging capability. 300 AH is a lot for a simple 26 footer and a 1GM does not have the capacity to charge that effectively.

Actually Michael has 3 problems. First keeping the batteries charged when not in the boat. Second using them effectively when he is off cruising. Thirdly not having much money, so having to make best use of his limited resources.

That is why I suggested he read up on the subject so that he can choose wisely!
 
Re: Help, i\'m running out of budget and need a decent charger

Argos do a Black and Decker 30amp 3 stage charger with error codes an d charge display which works alright running off a Honda EX650 genny. if it switches off it comes back on again, like it is 'pulsing' the power into the batteries or something. £67 currently at Argos. It does require 'user interaction' in that you have to press the 2/10/30 amp charge button three times to get it to start so it isn't a 'fit and forget type'.
 
Re: Help, i\'m running out of budget and need a decent charger

Thats his budget con for the year:).......Maybe Halcyon's suggestion...That is if you can find an unregulated charger???
 
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