Lead acid vs Gel cell

Lead acid or Gel cell for starter battery 12v

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Jamesuk

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Which should you choose for a starter battery?

The scenario - sailing yacht.

Liquid lead acid or Gel*

Ps pretty ignorant of batteries and there make up just squatting up on them.
 
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Does not really need a poll. Basic lead acid is usual if it is just a dedicated starter battery and you have space. Gel batteries such as Red flash or Odyssey are sometimes used as they have the advantage of being very compact and can be mounted in any orientation - so useful if space is short and you want to use the space to increase the capacity of your domestic bank. Of course it comes at a price - typically twice a lead acid.
 
Ok thanks, before i nip off to the rowing club ill give the reason for the question.

We recently had an old Gel cell starter battery removed and it was replaced with a lead acid battery (Varta promotive blue 140Ah, lots of good reviews) and at the time we were plugged in to shore power engine started after the 24hour period of charging and off we went. The very next start sounds like it stuggled for a split second by the 5th we were using the emergency Combine with domestic switch and it worked perfectly each time.

We thout it might be the battery as on paper it fitted the spec. We got a new one and did the same tests and we had a repeat of the same above.

NOW we have a 225Ah Varta Promotive silver and i just put it in and will test it tonight.

We had an engineer onboard For something else but maybe he got confused on price and i asked which was better and he said AGM best, gel cell then Lead acid for engine starter but ill give him the chance to have been thinking price as opposed to quality now you mention the differences.

Just. Checking out the info on Varta, reads like a pretty awesome start battery! So i wonder why we have the problems....
 
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Gel calls AGMS and wet lead acids all need quite different charging regimes and mixing them in a single bank is a big no no.

I like wet lead acid golf cart batteries on the house side and dedicated wet cell starter battery with a high CCA.

In the Caribbean gel cells seem to have a high failure rate when the golf cart batteries just keep chugging along.
 
Jamesuk said:
Ok thanks, before i nip off to the rowing club ill give the reason for the question.

We recently had an old Gel cell starter battery removed and it was replaced with a lead acid battery (Varta promotive blue 140Ah, lots of good reviews) and at the time we were plugged in to shore power engine started after the 24hour period of charging and off we went. The very next start sounds like it stuggled for a split second by the 5th we were using the emergency Combine with domestic switch and it worked perfectly each time.

We thout it might be the battery as on paper it fitted the spec. We got a new one and did the same tests and we had a repeat of the same above.

NOW we have a 225Ah Varta Promotive silver and i just put it in and will test it tonight.

We had an engineer onboard For something else but maybe he got confused on price and i asked which was better and he said AGM best, gel cell then Lead acid for engine starter but ill give him the chance to have been thinking price as opposed to quality now you mention the differences.

Just. Checking out the info on Varta, reads like a pretty awesome start battery! So i wonder why we have the problems....
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What sort of engine do you have? I've got a 4 cyl Yanmar and a 55Ah lead acid battery bought from an auto factors for not much over £50 three years ago. It starts first time every time. By the way it is the CCA that really matters for starting - starting batteries have to deliver high current for short periods of time, which is very different from what a domestic battery typically has to do.

Coincidentally, I did have major problems with the starter battery when I first bought the boat and the symptoms were similar to yours. Turned out that the previous owner had replaced the shorepower charger and messed up the fitting, which meant the starter battery was never being charged, so performance progressively dropped off until I had to resort to starting off the domestics (which were being charged). May well not be your problem, but worth a quick check.
 
Some basics:

Gel batteries are lead acid batteries.
AGM batteries are lead acid batteries.
Gel and AGM are NOT the same.
Gel batteries are poor starter batteries.
Almost all AGM batteries are extremely good starter batteries.
Odyssey and Red Flash are both AGM not gel and have exceptionally high starting performance.
Flooded lead acid batteries are generally the best cost effective solution for engine starting batteries or house batteries (but not the same model for both duties).
Use AGM if small physical size or non-spillability are very important.
Varta are extremely good batteries. It is highly unlikely that your problem is a faulty new Varta battery, but of course no manufacturer has a zero defect rate.
A 140Ah starter battery is appropriate for a reasonable size truck engine.

Almost certainly there is something seriously wrong with your charging regime or you have something flattening the battery. I'm afraid you haven't given enough detail to make any specific suggestions.
 
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Your problem is not, and was not, the battery.

If the domestic battery is charging, you have a fault in the device which decides what to charge.

If not, then you probably have poor contacts in the heavy current connections or a broken low current wire.

What does your charge light do?
 
Troubadour said:
Some basics:

Gel batteries are lead acid batteries.
AGM batteries are lead acid batteries.
Gel and AGM are NOT the same.
Gel batteries are poor starter batteries.
Almost all AGM batteries are extremely good starter batteries.
Odyssey and Red Flash are both AGM not gel and have exceptionally high starting performance.
Flooded lead acid batteries are generally the best cost effective solution for starting batteries.
Use AGM if small physical size or non-spillability are very important.
Varta are extremely good batteries. It is highly unlikely that your problem is a faulty new Varta battery, but of course no manufacturer has a zero defect rate.

Almost certainly there is something seriously wrong with your charging regime or you have something flattening the battery. I'm afraid you haven't given enough detail to make any specific suggestions.
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Awesome will read it over a few times to sink in :-)))

Can i ask the question - is swapping over a 12 volt battery as easy as changing a light bulb? That was the impression I got from the company that did it.

The battery gel cel lead acid came out and a Varta went in. Thats all and now we have a problem, sadly we dont have the old one to test.
 
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Jamesuk said:
Can i ask the question - is swapping over a 12 volt battery as easy as changing from halogen to LED lights?
Click to expand...

Are you being ironic? Have you read the threads on here about LEDs? Rocket science!

If you change to a different type of lead acid battery you may need to change the charger settings but it would normally take some time to show up as under or overcharge.

Are you sure the old battery was gel? Any details of it?
 
Yes i think it was because i called the company and they said they were "improving" the system with this new type of Varta from the old Gel

Im looking at the remote digital read out 13.14v in the battery on charge which runs the genset and main engine. Yes, i know, i know. The mastervolt manual said it can be done ;-) so the boat builder did it 5 years ago.

Ill run some tests for cranking the engine now. I really need another person to help me but ill do my best for tonight and fill in the blanks tomorrow. I switched over to the domestic bank from shore ( now not charging) the voltage on the battery stayed the same.

Just started the main engine (not mastervolt genset) and on returning to the digital read out it says 12.9v i guess that is normal. I need that extra person to check the voltage at the battery on cranking.

Anyway just realised the dutch are onboard nextdoor so switched pff the engine and will try again tomorrow whoops its past midnight here
 
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dt4134 said:
They're quite low voltages for a battery that is on charge.
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Whoops im bad, i had the dial set for trickle charge when in port for long periods so mow with it all the way up the starter has 14. 4v on charge.

I have a BTM master volt control panel manual to read so good night and thanks
 
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14.4 is a good recharge voltage up to something like 85% state of charge. Above that it will gas excessively.
13.14 is barely enough to maintain a fully charged battery and will not provide any recharge whatsoever.
If you only have those two settings your battery will never be properly charged. You need a period at 13.8-14 to complete charge. 13.8 could be left on for long periods.
You need to look at that for the longer term but I don't think it explain your immediate problem.
Unless the battery is faulty something is killing it.
(Gel batteries are more sensitive to water loss, that is presumably why your float is set so low.)

Later:
Just had a look at Mastervolt website. If your charger is same spec as their current range - you didn't say how old yours is - it's 3 step with an automatic boost from the low float voltage every couple of weeks and if you leave it on automatic control set for wet cell you should have no problem. Settings are not quite what I would choose but battery and charger manufacturers do tend to disagree a bit!
 
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Going through the checks, it may be a poor connection some where. If you could see what i see in a cupboard you may well just call up a pro to look into it. We have at least 30 red and black cables in there. The red have been labelled but the black has not.

The black negatives are where we think the problem now lies.
 
We use gel cranking batteries for the engine, generator and electric anchor winch.
Slightly off the subject we use 2 x 6 volt deep cycle Trojan batteries wired in series for the house batteries.
 
Jamesuk said:
Going through the checks, it may be a poor connection some where. If you could see what i see in a cupboard you may well just call up a pro to look into it. We have at least 30 red and black cables in there. The red have been labelled but the black has not.

The black negatives are where we think the problem now lies.
Click to expand...

I had to back document mine. As well as a circuit diagram I drew a diagram looking down into the battery compartment showing what each wire was and where it went when it left the compartment.

A bit of work now but it'll help in the future as you sort things out.

By the way, if you've got a decent digital multimeter you should be able to detect the poor connection by sampling voltage at various points and determining where the voltage drop is.
 
dt4134 said:
By the way, if you've got a decent digital multimeter you should be able to detect the poor connection by sampling voltage at various points and determining where the voltage drop is.
Click to expand...

Yes i think that is the plan. Al the terminals look clean as a whistle. We are getting some cables to bypass the 12volt starter switch. We now think it could be that which has failed possibly corrosion inside where the eye cannot see.

We really are shooting in the dark but one thing for sure is below

Cranking the engine shows a drop from 12 to 10 then 12 to 9 then 12 to 7 at the perkins 225 engine we flick over the the service bank "emergency start" which is made up of 2x6v Rolls and boom it starts immediately.

I have a local coming to look at it on Monday but for the time being we have this huge Silver promotive 225ah battery AND another perfectly decent 12volt starter battery promotive blue 180Ah on board the latter has been placed away from the circuit while we continue to trouble shoot.

I thought it was about 30kg (225Ah silver varta) but i checked the spec and i got that 57KG battery from the marina reception down the dock up the gangway, past all the varnish, down the steps and into the battery bay solo. Thank god for going to the gym daily and rowing. My back has no problems but then my training at Tesco on how to lift might have had something to do with it too :-)

Anyway we march on. I just polished the stern, painted the engine mounts and Inflated the dinghy and looking forward to movng the boat on Sunday night. Thanks for the continued suggestions/training, best get to sleep although the thumbing music is keeping me up, i have varnishing to do in 4 hours!!!
 
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Right we think it could well be the starter motor.

What do you think of this theory.

The starter motor is on the way out. With the starting problems before when we had the dudd battery the motor over heated melted the copper wiring inside together and now it requires a much higher current to start. A continuing downward cycle to start so perhaps this will mean the eventual death of the starter motor?
 
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