Starter battery

[STOL71]

I have a starter battery for my 2 cylinder 14 HP Nanni Diesel. I cannot decompress when starting the engine.
Battery did a good job but noticed that it doesn’t hold the charge.
It is a maintenance free acid battery and says 800 amps. Is that 800 CCA?
My understanding is that batteries with distilled water as suppose to acid are the better starter batteries.
My engine charges the battery and a 10W solar panel keeps it topped up.
I also have a leisure battery that works fine.
What should I get? Tips and input appreciated

 

[duncan99210]

Any battery that'll fit in the space available and has the same CCA as your current one will do fine.
All batteries are lead acid by the way. Some require maintenance and have screw in caps for each cell so you can check the level of acid and top up as required with distilled water. Others are sealed for life and require no maintenance. I use sealed for life as they're fit and forget until they die.

 

[VicS]

800 amps is probably the CCA. That is what is most usually quoted

It might be the MCA ... similar idea but measured at 32F (0C)) rather than at 0F. MCA figures are approx 20 - 25 % higher than CCA for the same battery

It might be the maximum discharge current

800 CCA is fairly generous for a small engine.

The differences between the various types of lead acid battery are explained here https://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html

The most sensible choice, for compatibility of charging regimes, is probably to the same type as your leisure battery which might be a wet cell battery or it might be an AGM battery.

 

[BabaYaga]

I have a starter battery for my 2 cylinder 14 HP Nanni Diesel. I cannot decompress when starting the engine.
Battery did a good job but noticed that it doesn’t hold the charge.
It is a maintenance free acid battery and says 800 amps. Is that 800 CCA?
My understanding is that batteries with distilled water as suppose to acid are the better starter batteries.
My engine charges the battery and a 10W solar panel keeps it topped up.
I also have a leisure battery that works fine.
What should I get? Tips and input appreciated

Do you use a good solar regulator with a low enough float voltage? If not, it might well have been over charged and dried out. Putting solar to stater batteries only makes sense if the boat is left unattended for long periods IMHO.

 

[macd]

My understanding is that batteries with distilled water as suppose to acid are the better starter batteries.

I presume some helpful software inserted "suppose" where you intended "opposed"?

Even if so, what you write is either poorly expressed or the subject poorly understood. All lead-acid batteries contain (sulphuric) acid. During charging, some of the water in the acid can be lost by a process known as "gassing". Distilled or de-ionized water is then added to bring the remaining acid up to the prescribed level. Some batteries, usually called "sealed" or "maintenance-free" are designed to prevent or reduce such water loss. There are also other types of lead-acid batteries (AGM, gel) which employ a different means of holding the acid against the lead plates. Most starter batteries however, are simple "flooded" lead acid, either "open" (able to be topped-up) or "sealed" (not readily able to be topped-up).

You'd be well advised to read the link VicS suggested for further info.

 

[STOL71]

Many thanks for all that helpful input.

I indeed have a rather poor understanding of the subject at hand; plus I am a foreigner (EU-National), hence my poor expression.

After I've charged and disconnected the starter battery from the charger, it shows 13.3 V on the voltage meter. A day later is shows 12.8 V.
I read that 12.8 V means it's fully charged. Maybe there's nothing wrong with my battery after all?

 

[VicS]

Many thanks for all that helpful input.

I indeed have a rather poor understanding of the subject at hand; plus I am a foreigner (EU-National), hence my poor expression.

After I've charged and disconnected the starter battery from the charger, it shows 13.3 V on the voltage meter. A day later is shows 12.8 V.
I read that 12.8 V means it's fully charged. Maybe there's nothing wrong with my battery after all?

12.8 volts a day later is a good sign. It would be interesting to see how quickly it falls over a few days or weeks with no further charging or load. A really good battery will take several weeks to fall below 12.5.

However, it does not necessarily mean that the battery will deliver the current required by a starter motor. Some kind of high discharge test is needed .... although quite a good test is to try starting the engine!

 

[pcatterall]

12.8 volts a day later is a good sign. It would be interesting to see how quickly it falls over a few days or weeks with no further charging or load. A really good battery will take several weeks to fall below 12.5.
Yes,
That has been my recent experience, the battery would deliver low current quite well. As I tested it over several hours with. Just a 5amp load, the volts dropped as expected but even after charging I found it did not have much cranking grunt!
Ignore the rude comments from some forum members!!

However, it does not necessarily mean that the battery will deliver the current required by a starter motor. Some kind of high discharge test would needed .... although quite a good test is to try starting the engine!

 

[PaulRainbow]

12.8 volts a day later is a good sign. It would be interesting to see how quickly it falls over a few days or weeks with no further charging or load. A really good battery will take several weeks to fall below 12.5.

However, it does not necessarily mean that the battery will deliver the current required by a starter motor. Some kind of high discharge test is needed .... although quite a good test is to try starting the engine!

I did a service on a yacht a few weeks ago, both domestic batteries were bone dry and looked very unwell internally, yet they showed a good voltage on the boats volt meters. I turned the charger off and out of curiosity i checked the voltages a week later, both were showing 12.8v. Soon as anything was turned on they could go flat quick enough

 

[CCJ]

I did a service on a yacht a few weeks ago, both domestic batteries were bone dry and looked very unwell internally, yet they showed a good voltage on the boats volt meters. I turned the charger off and out of curiosity i checked the voltages a week later, both were showing 12.8v. Soon as anything was turned on they could go flat quick enough

That is one consequence of batteries on permanent charge, how long before something went seriously wrong

 

[PaulRainbow]

That is one consequence of batteries on permanent charge, how long before something went seriously wrong

More a consequence of having open cell lead acid batteries and not topping them up.