Engine starting from a "Leisure" battery

[gandy]

Engine starting from a \"Leisure\" battery

Hi,

Our number 2 battery, a fairly new 85AH Exide Leisure battery was our normal engine start battery for the last couple of years. Now over the winter its died. It was given a top up charge every few weeks, but now after being left for a couple of weeks it doesn't have enough oomph to turn the engine. Clearly it needs to be replaced.

I wonder whether using it for engine starting was a factor in a fairly young battery failing?

Tony S

 

[cindersailor]

Re: Engine starting from a \"Leisure\" battery

Check all the cable connections before condemning it.

 

[Conrad]

Re: Engine starting from a \"Leisure\" battery

In the old days to keep ones batteries conditioned a charge and discharge cycle was a good idea, try running it flat then charge it for a day or two, do allow for a long charge as to get 85ah into a battery at a rate of 2-3 amps per hour can take that long.

 

[maxi77]

Re: Engine starting from a \"Leisure\" battery

Equally have you checked the battery selector switch

 

[rogerdog]

Re: Engine starting from a \"Leisure\" battery

My understanding is that a "leisure" style battery has a different place design that is less tolerant to high current applications (as it's designed to be discharged to at least 50% of capacity) So starting the engine will take a very large current for a short period of time followed by a small charge cycle - ie only a small amount of the active plate material will be converted each time.


My feeling would be that using it as a starter battery would contribute to its decline.

 

[gandy]

Re: Engine starting from a \"Leisure\" battery

[ QUOTE ]
Check all the cable connections before condemning it.

[/ QUOTE ]
[ QUOTE ]
Equally have you checked the battery selector switch

[/ QUOTE ]
Both good points, and I can easily check by moving the cables off the "bad" and onto the "good" battery. No point in buying a new battery if the fault lies elsewhere.

I have the bad battery at home, on a smart charger. If it recovers we'll use it for the electric fence which currently uses a battery borrowed from the digger. In good nick, an 85AH battery should run the fence for nearly two weeks before showing low on the energiser.

 

[boatmike]

Re: Engine starting from a \"Leisure\" battery

Theoretically a "cranking" battery is designed to take high Amp loads for short periods but does not like deep cycling, i.e. running lights and services for long periods without the engine running until deeply discharged. A true "deep cycle" battery is the opposite and is not good at cranking loads. A "leisure" battery is a compromise between these two extremes and will tolerate short periods of high cranking loads OK but if your engine is hard to start and you have been using a leisure battery over and over at high Amps until it is deeply discharged it won't like it. If your engine starts first or second turn of the key thats fine but if you have hammered it repeatedly to start it ..... yes that will reduce it's life. If your engine is notoriously hard to start a truck or lorry battery would be better, but won't like to be deeply discharged. It's all a compromise.

 

[VicS]

Re: Engine starting from a \"Leisure\" battery

[ QUOTE ]
Clearly it needs to be replaced.

[/ QUOTE ] I'd take it off and bench charge it. See if you can get it to charge, then see if it will retain its charge.

If it's good you should be able to get it up to 12.7 to 12.8 volts measured after resting for 12 hours and it should still be at 12.6 ish a week or so later.

As others have said leisure batteries are a compromise. My previous (Lucas) leisure battery was marked with CCA figures but the new one (Halfords) is not.

I think I would agree with the sentiment that an ocassinonal duty for engine starting may be acceptable but regular use may not be.

 

[Bilgediver]

Re: Engine starting from a \"Leisure\" battery

All the comments here are valid regarding the advantages and disadvabtages of using a leisure battery for starting. However in my experience here and on the river the biggest problem is folk trying to charge 100 a/h leisure batteries with the likes of HAlfords do all fully automatic chargers.

MAny of these chargers seem to cop out and shine green lights as soon as they hit 13.8 volts which means the leisure battery never sees that extra spurt it needs to equalize.

A leisure battery seems to need that occasional burst of 15 volts from time to time to ensure all cells are enjoying some rejuvenating.

I have seen one of the new Halfords chargers when connected to a duff leisure battery switch from charge mode to maintanence mode withing 5 minutes of going on charge. Too many safety devices /forums/images/graemlins/smile.gif

 

[gandy]

Re: Engine starting from a \"Leisure\" battery

Interesting comments on the smart chargers. At the boat I use a Sterling Pro Budget 10 amp charger. During the winter, each time we visit I couple up the charger and usually it switches to "float" after 15-30 minutes of "equalise".

The dud (or let's say suspect) battery was charged like that two weeks ago, then this weekend it wouldn't turn the engine.

At home I use a small smart charger, originally bought for the mower and motorcycle batteries that would be damaged by a high charge rate. It takes days to get a 100AH battery up to scratch, but seems to keep them in good condition.

 

[Conrad]

Re: Engine starting from a \"Leisure\" battery

Regarding charging, what may be a 10a charger after that initial inrush of current and rise of voltage you will probably find the charge current goes down to about 1-2 amps or less this is why you need a long charge possibly up to 2 days. When I worked on specialist DC battery systems we use to have 72 hours down as the full charge time. This is why car batteries do not seem to respond well (especially in older cars) with only that overnight charge.
Also allowing the batts to discharge in lead acid cells does prolong the batt life, not sure if it makes any difference in the gel cells, there is a complicated scientific reason which escapes me.

 

[ms1]

Re: Engine starting from a \"Leisure\" battery

May I suggest
charge it for a couple of days.
take it to a battery shop and get them to test it .. dont muck about yourself trying to establish if it is dead or not.
I doubt whether engine starting has killed it, although Leisure batteries are not designed to give a massibv=ve belt of power. When I replace a battery I always get something that has a 3 year guarantee.

 

[gandy]

Re: Engine starting from a \"Leisure\" battery

Hmm. Not sure I agree with some of these points.

Conrad - Both the Sterling and the little "Accumate" charger switch onto a float charge once they think the battery is full, so it wouldn't make a lot of difference leaving them connected for longer. The only difference is that the Accumate has such a small output that it takes a long time to reach that stage. It definitely fully charges our electric fence battery which is a Massey Ferguson branded battery designed to start a big Diesel. The Sterling does similarly well, but quicker.

I agree that a non-smart charger needs a long time - I've had the digger battery on charge overnight then found it unable to start the engine next morning.

Martin - if it can't start the engine after standing for a couple weeks then its no good for our boat, no real need for a test to tell me that.

 

[philip_stevens]

Re: Engine starting from a \"Leisure\" battery

Don't just check the voltage, as even a battery with a duff cell will show a "good" voltage for a while with no load. The main thing to check after a good charge, is the specific gravity of the electrolyte - the acid.

You may find that one cell shows a low S.G. compared to the other cells. I have just replaced one leisure battery that showed good, but had one duff cell.

Another way to find if you have a duff cell in the battery, is to put it on high charge and check to see if just one cell is bubbling more than the others - that is the duff cell.

This Adverc page will show the S.G. you should expect to see.

The following from MPowerUK
SOC from Specific Gravity (SG) Measurements

This is the customary way of determining the charge condition of lead acid batteries. It depends on measuring changes in the weight of the active chemicals. As the battery discharges the active electrolyte, sulphuric acid, is consumed and the concentration of the sulphuric acid in water is reduced. This in turn reduces the specific gravity of the solution in direct proportion to the state of charge. The actual SG of the electrolyte can therefore be used as an indication of the state of charge of the battery. SG measurements have traditionally been made using a suction type hydrometer which is slow and inconvenient.

Nowadays electronic sensors which provide a digital measurement of the SG of the electrolyte can be incorporated directly into the cells to give a continuous reading of the battery condition. This technique of determining the SOC is not normally suitable for other cell chemistries.

VicS will probably add to this.

 

[VicS]

Re: Engine starting from a \"Leisure\" battery

[ QUOTE ]
VicS will probably add to this

[/ QUOTE ] That just about says it. The sulphuric acid forms lead sulphate while the battery is discharging and when it is recharged the sulphuric acid is reformed again. I'd probably have also given the link to Mpoweruk as well,
There a state of charge table giving volts and SG on the Battery faqs website at different temperatures and for different battery types, but I usually get higher voltages than they give.

Your hydrometer is not much good for sealed batteries, AGM or gels /forums/images/graemlins/grin.gif

 

[William_H]

Re: Engine starting from a \"Leisure\" battery

Gandy doesn't say what kind of engine he has been starting. ie how much cranking current he has been taking out of the leisure battery.
I think CCA (cold cranking amps) is a relative thing in that a starting battery can give a lot of CCA for its size. But I think that a large 85AH battery will give a good CCA ie similar to a small starting battery.
So unless it has been trying to start a big diesel engine the engine starting has probably not been detrimental to the battery life.

I reckon all battery chargers should have an amp meter. Then you know what is actually put into the battery. Little green lights just tell you the charger thinks the voltage is high enough to go to float.

In my experience however batteries don't last forever and the battery is probably dead if you find it won't do the job you want. It may however still be usefull as a service battery for low current drain lights etc.

good luck olewill

 

[VicS]

Re: Engine starting from a \"Leisure\" battery

[ QUOTE ]
Gandy doesn't say what kind of engine he has been starting

[/ QUOTE ] Well not a whacking great big one in a 26ft yacht I guess. Originally Griffons were fitted with 13hp Volvos or 10 or 20 hp Bukhs.

 

[gandy]

Re: Engine starting from a \"Leisure\" battery

[ QUOTE ]
Gandy doesn't say what kind of engine he has been starting. ie how much cranking current he has been taking out of the leisure battery.

[/ QUOTE ]Yes, that was a bit silly of me, as the battery size is meaningless out of context.

Its a Volvo MD7a 13HP Diesel, 750 cc. The starter motor is rated at 800W or 1.1HP. I note that Volvo recommends a maximum battery size of 70AH - that must be to do with the fairly small alternator, but I suppose it suggests that Volvo think a 70AH battery of some sort or other should be up to the job.

For what its worth Squadron told me that either their FLA or SFL 85AH dual-purpose batteries would be OK to start that engine without harm.

The whole thing's a bit confusing. Squadron for example give full spec for all their batteries, including CCA. Their deep-cycle batteries, described as unsuitable for starting, still show just as high CCAs as their dual-purpose. Maybe it doesn't indicate that they can deliver it without damage. I tried to look up the spec for Exide but it doesn't seem to be readily available.

 

[asj1]

Re: Engine starting from a \"Leisure\" battery

I agree with many othersb using it for starting will be teh problem.
Similiar happened to me and it only lasted one year. In my case though I had purchased two leisure batteries and one engine battery on the internet, but all three batteries looked and weighed and appeared to be identical !!

 

[gandy]

Re: Engine starting from a \"Leisure\" battery

When we got the boat it had one old knackered 75AH battery and one new 85AH, both branded Leisure batteries. Clearly the previous owner had been starting off them, but he said he always kept it switched to "both". I replaced the dead 75AH with a 115AH Leisure to serve as Domestic and kept the 85AH as Start.

That system has worked OK as long as I remember to switch between them, so I think I'll get an ordinary car battery as the new Start.

The only worry is that sometimes I start off the Domestic, either through laziness or forgetfulness. I'll just have to try and to remember not to, though I guess it'll do less harm to that bigger battery.