Battery charging

mick

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Can I use an ordinary Halford's type charger to charge my batteries on the boat without disconnecting the terminals. Do I need to undo the caps on the cells?
 

Niander

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Can I use an ordinary Halford's type charger to charge my batteries on the boat without disconnecting the terminals Yes

Do I need to undo the caps on the cells? No
 

bluedragon

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Assuming it's a modern one, you're OK. I use a Halfords Fully Automatic charger both on the boat and at home. It charges at around 14.8V for a few hours and then drops to about 13.6V float charge. Slight gassing (as expected) but it does it's job very well. No need to loosen the caps on mine.
 

webcraft

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A friend gave us a Halfords Fully Automatic charger model no. BFH-1275AM

I thought you had to disconnect the batteries before using it, so this is good news - althoug the charger only mentions automotive uses, not marine.

Are there any electrolysis implications? Normally we don't connect our shorepower to the boat systems in any way.

And should we switch everything off on the boat before connecting the charger, or doesn't it matter? (Sorry , not v. good with electricity)

Also - we have 1 x 95AH engine start battery and 1x110AH domestic battery, with a 1-2-Both switch. The charger says it is suitable for up to 110AH, so presumably we should only charge one battery at a time by having the switch turned to either 1 or 2 but never both?

- Nick
 

William_H

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An ordinary battery charger may mean the old transformer rectifier type. Hopefully with an ampmeter. Yes however....
This type has either a resistor in the output to limit the current in the case of a flat battery or it relies on the internal resistance of the transformer to limit the current.
So these chargers produces a relatively large voltage of approx. 18 volts in the form of sine wave peaks. The voltage rises from zero up to 18 volts then decreases again at 50 or 100 times per second.
When this voltage tries to raise the battery voltage because it is connected to it. The current flow reduces the voltage to the inherent voltage of the battery ie around 14.
The higher voltage does mean that the charger continues to put current into the battery as the inherent voltage rises because the battery has become more charged. This is good in that it gives you closer to a constant charge current but does mean that the battery can be overcharged. You have to remember to turn it off.
However if you are just puting in a bit of charge while you are tied up to the jetty with limited time then this type can be your fastest charger.
This type is usually identified by having an ampmeter and no charge or status indication lamps. (except possibly power on light)

A regulated charger gives precisely 14 volts and the current flow in is determined by the difference between the battery inherent volltage and 14 volts. This can start off at 2 volts difference giving a decent current but quickly becomes .5 volt (hence 1/4 current) and less as the battery charges. You can never overcharge the battery no matter how long it is connected. This type emulates the regulator on your car or standard regulator on your engine alternator.

The more sophisticated chargers as suggested will charge at a higher voltage hence current until it senses that the battery is mostly charged then will reduce the voltage to give a low current for long term. They usually have lights to tell you the status. A sophisticated smart charger regulator will make the aternator do the same thing.

Most chargers with possibly the exception of the last type will not be
upset or damaged by having both batteries in paralell for charging.
If the batteries are really flat then you should check the charger for signs of overheating.

Electolysis is not a concern for occasional charging from the mains which is only connected for several hours. It can be a whole different story if the mains are connected 24/7 for months. Even if not powering anything.

The electrical devices on your boat are made to run happily on 14 volts whch is the situation when the engine is running charging the batteries. Most electronic devices will happily take the higher voltage possible with the higher voltage of the old crude chargers and the smart chargers. ie about 15 volts. However lights may have a shorter life and I think it may be prudent not to turn expensive devices on when the charger is on. Having said that I have not heard complaints of failure from people using smart chargers on their engine alternators. Certainly you don't have to disconnect the battery. good luck olewill
 

bluedragon

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I think William has answered the questions much better than I could. What I can say is that I've used a Halfords KAH-1211AM charger for the last two years, whilst cruising and we've been at a pontoon with shore power. Typical use has been to charge the batteries (both in parallel) for about 12-24 hours. Often we've been on board and using lights, etc, at the same time. Doesn't seem to have harmed anything. Although not specifically stating marine use, it states suitability for deep cycle leisure batteries, inc. gel types, and for golf carts and other electric vehicles. So as long as you're using this as an occasional charger rather than fixed, all should be OK. It does say that the output is not AC-free, so any AC sensitive equipment should be disconnected (whatever that means...). I always carry this charger on board during the summer cruises, and it's done the job for me.
 

bluedragon

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It worked for me with a 65Ah start battery and 85Ah service battery connected via a VSR. Neither were deeply discharged. That's all I can tell you. The charger does indicate a max. battery capacity of 110Ah however. Why this value is set as it is, or what might happen if it's exceeded, I've no idea.

PS - on reflection, with the inevitable sulphation, the actual capacity of the two batteries might not have been (much) above 110Ah. With a larger bank or flat batteries it may well be prudent to charge them separately. Do others have any thoughts on this?
 

bluedragon

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WARNING!!!

Just found out that my charger is subject to a product recall! The Halfords website says the following:

"We have identified a potential safety concern with the HALFORDS FULLY AUTOMATIC BATTERY CHARGER. It is possible that when charging a defective 12 volt battery that the charger could overheat.

If you have purchased one of these chargers since January 2006, please return it to your nearest Halfords store. The barcode is: 5015025370828, and the item code is: 370825 and are shown in the picture above.

No other battery charger is affected.

The return product will be exchanged. If you have any queries, please speak to a member of staff or call Halfords Customer Helpline on 08450579000 "

On my way to Halfords...
 

Sammo

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I am at the moment in the process of wiring the boat and looking around for a charging system that doesn’t cost the earth I found one from a company called “Sterling power products” in Worcester…..this charger is about £250 for the 30 amp build in unit which is affordable compared to many others and it will do three batteries at once with three dedicated connections ….the unit itself is a four stage charger …this means it goes through four different stages to charge the batteries …depending on how it senses the battery state …it will also periodically carry out a 7 day de-sulphating cycle keeping the battery plates in good condition.

Sterling charger

The battery charging off the 90 amp alternator on the engine had to be split 3 ways and although Sterling make a 3 way diode splitter I was not to happy with the voltage loss across a diode ( .7 volt) as this means the batteries can never be fully charged….so I decided on the Vetus unit which uses mosfet transistors instead of diodes and give a negligible drop of .1 volt.

Vetus batterywatch

Although the Vetus unit was expensive at around £290 it does come with a remote digital display which when mounted on the dash gives a clear indication of the battery states and charge rates of all three ……I finished fitting it all yesterday… now I just have to try to tidy the miles of wiring.


..
 
G

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Fine - William - but Webcraft is talking about similar charger as I have which is fully automatic and can be left connected indefinitely .... albeit with regular checks of electrolyte level. Some like mine hace switch to choose Gel or Wet ...
They are excellent chargers and maintenance machines. Only thing they don't like is having charge output split across a charge splitter ... but across a 1-2-off switch is no problem.

As to original post - IMHO he can connect Halfords charger and use no problem - like thousands of others do .. and as most Halfords / auto chargers are about 4 - 6A normally - without other indication or data - he can divide a/hr capacity of his batt's by 5 and arrive at theoretical charge time and be safe ... even though we all know that charge time is dependent on many factors and is not really so simple a maths ...

As an aside .... I use my halfords Auto charger for all those "other" jobs now .... garden tractor / car etc. I have reverted to an old cheapo Car charger connected to a Maplins charge splitter which looks after my two onboard batterys. Charger about £10 .... Maplins spliter £7 (think they may have increased to about £9 now ... but still excellent value) ... and a £5 mechanical 240V timer. The timer is set for a few hours for a number of days a week - with 2 days in the week rest ... so batt's are given regular top-ups to keep in near full charge condition. I purposeflly use no boost items at all - as I believe a battery pushed to its limit is not in my best interests !! Having had batt's survive many years on board - I consider my policy to work !!

If I do want to be brutal - I have recently bought a manually regulated 6 - 12 - 24V charger for looking after my Truck batts (24V .... twin 12V) .... this can be set to anything from 0 to 10A constant and is designed to punch into large HD truck jobs ... But it would have to be a real emergency for me to use it on the boat !!

/forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/cool.gif
 

bluedragon

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Re: WARNING!!!

Just exchanged it. No problem. Girl on the checkout knew all about the recall. The instructions on the new model have changed a little, and that affects some of the information and opinions given earlier in this thread.

It now clearly states a 110Ah max. battery size. It also says to charge no more than one battery at a time. AND... for marine batteries, the battery should be removed and re-charged ashore, as to charge in-situ requires special equipment.

These warnings were not present on the previous model so-far as I recall. So in spite of what I said earlier, the official line from Halfords is that they are NOT to be used onboard!
 
G

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Re: WARNING!!!

[ QUOTE ]
Just exchanged it. No problem. Girl on the checkout knew all about the recall. The instructions on the new model have changed a little, and that affects some of the information and opinions given earlier in this thread.

It now clearly states a 110Ah max. battery size. It also says to charge no more than one battery at a time. AND... for marine batteries, the battery should be removed and re-charged ashore, as to charge in-situ requires special equipment.

These warnings were not present on the previous model so-far as I recall. So in spite of what I said earlier, the official line from Halfords is that they are NOT to be used onboard!

[/ QUOTE ]

Halfords soon to announce their "Marine line of items". (Joking of course !!)

Having used the very one that is subject to recall for more than 2 years ... possibly 3 ... I have never had any problem with it and will continue to use on board as and when needed. (Not my advise to others ... just my decision personally ... I live in Latvia and it is not possible for me to exchange without incurring greater cost than the article ... ).

I have reasonable confidence in my item as I have connected to many different batterys of many different a/hr and conditions ... including defective. The charger has not heated / faulted in any way. I note the recall is for those bought Jan 2006 and on ... mine I seem to recall I bought early 2005 ... ??

I can understand that it is not "sealed" against Marine environment and HS&E would require them to be ultra careful and warn people not to use where danger of shock etc. occurs.

It's like all things really in life - sensible use and precautions and HS&E is unnecessary .... they have to cater for the one or two idiots.
 
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