Batteries

[newf]

I have to buy 2 new batteries and can anybody tell me why I should pay £70/80 rather than £50/60 when they are both 110v and both 'marine batteries' and both warranteed for 2 years . Both quotes from the same supplier with the explanation that 'that one is better than that one' ............confused or just sales pitch ?

[senator]

feel the weight of the batteries. If one is heavier than the other then it is because either the plates are thicker or there are more of them, depends what type of batrey it is.

If there is no difference in weight is one sealed and one open cell or even gel.

Lots of differences in them but it is hard to seperate the trade name mark up from a genuine advantage.

[w44nty]

I just purchased a new battery from Norfolk Marine Wroxham,85amphr for £57.83p.

[newf]

Thanks guys but my point is the quotes were from the same marine supplier both 110amp both 2 year warrantee so should last the same amount of time . I was even quoted for a 'Truck' battery same spec but £10 dearer but 'would be much better'. Now I understood that boaters should use marine type batteries and not ones that are made for road vehicals. Sorry but seems confusing.

[Antares_9]

A 110ah battery is not a measure of it's quality but it's new capacity, all 110ah (or any other equal capacity for that matter) are not created equal and can be of a differing quality and capability even though afforded the same warranty. Here is some reading that may elighten you a little.

http://www.mpoweruk.com/performance.htm

[w44nty]

After reading that link,I will be having nightmares,never new it could be so complecated,my idea of a battery is turn the key,and away you go,then I am only new to akll this.

[kfurbank]

As David has said, the 110Ah is a measure of a batteries capacity, not its quality. A cheap low end battery should charge and discharge somewhere in the region of 200 times before it stops holding a charge. The more expensive will allow anything up to 500 charge and discharge cycles. If you charge and discharge your batteries 100 times a year then one battery could just about last two years. A more expensive one may last up to 5 years, although age also has an effect on batter life as well.

Keith

[mbird]

Batteries, humph

This weekend I fitted the new battery linking solenoid, and I won't bore you with the details, but in doing so also discovered my battery charger is knackered, as it no longer isolates the outputs to the two banks. I also took all three batteries to Brian Wards for testing, and was told (as I expected) that two out of the three were shot. It also turns out that all three batteries were cranking type, not deep cycle, so that has probably help kill them off.

I ended up having to buy a new battery charger (got a very good deal though) and two 110ah deep cycle batteries for £68 each. I'm sure I could maybe have saved a pound or two elsewhere, but I have always found Brian Wards to be very helpful and knowledgable, and am happy to pay a little more for that help.

[newf]

What a can of worms and I also understand that some batteries need a particular type of charger.

[mbird]

What a can of worms and I also understand that some batteries need a particular type of charger.

I think most lead-acid and gel batteries use the same chargers. There is another type, though, which I think are called something like AGM (though I've probably got that wrong) that are supposed to be very good, but more like £200 each. I think they do need a different sort of charger.

[senator]

What a can of worms and I also understand that some batteries need a particular type of charger.

If you are using Lead Acid then the rate of charge that you can put in will depend on whether it is sealed or not. if it is sealed you need to charge them slowly or they blow up, spilling the contents of acid onto the hull, which if left will eat through and sink the boat.

Just make sure that once your insurance claim is settled you buy a boat with new batteries

[senator]

I think most lead-acid and gel batteries use the same chargers. There is another type, though, which I think are called something like AGM (though I've probably got that wrong) that are supposed to be very good, but more like £200 each. I think they do need a different sort of charger.

Is your new charger 3 stage with variable output Mark?

Make sure you turn it to the right setting for your new batteries.

[Antares_9]

"I think are called something like AGM (though I've probably got that wrong) " no you are exactly right Mark, Absorbant Glass Mat batteries are brilliant for fast charge capability unlike their other non spill cousin the lead acid gell battery, they will also take a lot more discharges as the plates are seperated by a solid medium and therefore don't suffer the sulphation common in a standard lead acid bettery. But, they hurt the wallet.

[Guest]

Hi Col

Battery drop tester

http://www.brianwards.co.uk/online-shop/100a-battery-load-tester.html

Jonny

[jimbo]

I tend to pinch my garage owning mates Snap-on battery tester for a weekend at the start of the season! They are great as they display a % indication as to the batteries efficiency. 60% or below and they are down the road

[mbird]

I tend to pinch my garage owning mates Snap-on battery tester for a weekend at the start of the season! They are great as they display a % indication as to the batteries efficiency. 60% or below and they are down the road

It was a Draper electronic type jobbie that BW used to test mine, and the two cream-crackered ones were only showing about 30Ah (from 95 Ah batteries), even though they have been on charge indefinately.

Is your new charger 3 stage with variable output Mark?

Make sure you turn it to the right setting for your new batteries.

Hi Ian,

Yes it is 3 stage and suitable for all lead acid types (sealed and un-sealed).

[newf]

http://cgi.ebay.co.uk/SEALEY-BT91-7-BAT ... 1c1040e90e

Is this what you were talking about Rod

[mbird]

That's the same type I used to borrow from DRL to test ours, Colin.

[Boaters]

Looks a handy bit of kit Rod.On BW site they are now £28 but state up to 100 amp ,is this OK ?

[newf]

Roy have a look at my ebay link

[newf]

Guys once again thanks to all of you for your input. I started off most confused about different types of batteries and I am now slightly less confused after re reading the thread several times.

[newf]

I have one more question folks then I will shut up. I have a switch over type isolater switch, No 1 is engine batt. No2 is domestic and I can have both together, my question is when I have No 1 batt. on and traveling am I charging both batteries or just No1

[Gordon]

Colin I am not even sure if the last question even is that simple. I go back to the advice I have given many times which is to invest in a cheap multimeter possibly digital for this use measure the battery voltage with the engine off, at a rough guess it should be about 12.5 volts start the engine and it should rise by at least a volt try it on both batterys and with the switch in both positions and it will tell you which is charging when.

Batterys can die in two ways, they can lose capacity as previously mentioned but they can also lose a cell or one or more cells go low capacity this again will be indicated by your cheap meter. Fully charge the battery, and then measure the voltage if below about 12.5 v you got problems or if it drops within a few minutes its bad news. Must admit I have always been too mean to buy any form of drop tester and use a bulb and a meter. Will get one one day cos having 2 110Ah in parrellel it is less easy to know when things are not tickety boo with one of them

[mbird]

I go back to the advice I have given many times which is to invest in a cheap multimeter possibly digital

I agree entirely with Gordon, Colin. I think I paid less than 20 quid for a B&Q own brand digital multimeter, and it is one of the most invaluable tools you can have (for electrics anyway!). Without it this weekend I wouldn't have been able to tell by charger was cream-crackered and buggering up the operation of a solenoid.

With regard to you question re charging though, it's impossible to tell without looking, as it could be that they are indeed both charged from the alternator all the time.

[Gordon]

You should be able to get a perfectly adequate one for less than a fiver and for 20 quid you will get one that will measure all sorts of things that have no place on a boat or car

http://cgi.ebay.co.uk/DIGITAL-MULTIMETE ... 5884e1369a

No need to go to ebay even any car accessory shop, diy shop, market stall and even dear old lathams