marine battery chargers are they worth the difference in price

[dunkelly]

As part of an adding extra capacity to my battery system i have been looking at upgrading my ctek m45 to a larger capacity charger and as usual there is a substantial difference in price between the normal automatic smart chargers for cars and the m100 in the c tek range . i was thinking i might just add a normal car smart charger from their range to the additional battery i am adding , i have the ability to completely isolate this new battery with an isolator switch . Am i likely to have a problem with this , has anyone done the same ? .

 

[PaulRainbow]

The M100 is only 7a, unless your battery bank is very small, it's not big enough and it is over priced anyway. For instance, a Victron Blue Smart 15a charger is as little as £118 : https://www.batterymegastore.co.uk/...blue-power-chargers/victron-bpc121541002.html

This is a single output, 3 outlet models are available, as are models that can be monitored from a phone or tablet.

 

[dunkelly]

currently i have a 100amp domestic , 80amp starting and i am adding a further 80 amp for domestic , the starter and domestic seem to charge fine on the m45 which is why i thought i would just charge the new one separately . is it a bad idea to use two chargers ?

 

[lw395]

currently i have a 100amp domestic , 80amp starting and i am adding a further 80 amp for domestic , the starter and domestic seem to charge fine on the m45 which is why i thought i would just charge the new one separately . is it a bad idea to use two chargers ?

It's a bad idea to do anything with batteries if you're too slack to respect the difference between Amps and AmpHours.

 

[BabaYaga]

currently i have a 100amp domestic , 80amp starting and i am adding a further 80 amp for domestic , the starter and domestic seem to charge fine on the m45 which is why i thought i would just charge the new one separately . is it a bad idea to use two chargers ?

Nothing wrong with using two separate chargers, but I would keep the m45 for the occasional charging of the start battery and size the new charger for the combined 180 Ah domestic bank. The 7A of the m100 might be a bit marginal, but could be OK if it is not essential to recharge completely over night. The m100 has a lot of features, like supply mode and reconditioning mode. You should evaluate if these are useful for you.

 

[dunkelly]

i am feeling my way round the subject as you may have guessed ,so thankyou for the advice .

 

[PaulRainbow]

i am feeling my way round the subject as you may have guessed ,so thankyou for the advice .

The M45 is little more than a trickle charger. But, as suggested above it wouldn't h urt to keep it for charging the engine battery. Get something big enough for the domestics though, the M100 isn't enough, the Victron is much better and is less money.

 

[Graham376]

Motorhome and caravan sites usually have chargers quite a bit cheaper than so-called marine versions. My 40 amp one can be switched to charge or, 12v power supply.

 

[pcatterall]

It's a bad idea to do anything with batteries if you're too slack to respect the difference between Amps and AmpHours.

Bit offensive isn't it?? The OP probably does understand but is just using non technical terminology. Cut some 'slack' yourself!

 

[fredrussell]

Bit offensive isn't it?? The OP probably does understand but is just using non technical terminology. Cut some 'slack' yourself!

Agreed. To the OP, just ignore lw395, he suffers from Captain Ahab Syndrome - there’s a fair bit of it on this forum.

 

[William_H]

Describing a battery as 100amps is technically incorrect and should be 100 Amp hours. However our language is so flexible that we may yet see this error become part of normal language. For instance when I was young a generator was a DC device making electricity from rotating magnetic field immediately by a commutator to give DC. An alternator was a similar device which intentionally produced AC at a frequency depending on the rotational speed. Then came an alternator for cars which was an alternator with attached diodes to produce DC. Fine now it seems with change of language an alternator produced DC and a device for producing 240v DC is a generator. There is no way my ranting will change the use of these words so we just try to go with the flow of language corruption.
Regarding battery chargers. The max capacity of the charger will dictate just how much charge you can get into a battery. Providing it produces more current than what is being used and natural losses in the battery a small charger will recharge a battery. (or bank of parallel batteries) just takes longer. So it might take a week to bring up a very low charged bank. Bu that may not matter to the OP. So I reckon stick with what he has and if he finds the need to recharge from mains faster then get a bigger charger or additional charger.
I think some people make comments to justify their own decision to have a bigger charger which do not necessarily apply to OP.
ol'will

 

[PaulRainbow]

Describing a battery as 100amps is technically incorrect and should be 100 Amp hours. However our language is so flexible that we may yet see this error become part of normal language.

So, if we're going to call amp hours amps, what shall we call amps ? Let's call them volts and volts can become ohms, ohms could then be called sausages.

Things have a name for a reason, so we all know what we're referring to, it's a big part of why we evolved to where we are at and are not still in the forest grunting to each other.

No disrespect to the OPs misuse of the term "amps".

So I reckon stick with what he has and if he finds the need to recharge from mains faster then get a bigger charger or additional charger.
I think some people make comments to justify their own decision to have a bigger charger which do not necessarily apply to OP.

My comments are based on the fact that the current charger is very small for the batteries installed and the fact that the OP is considering a 7a charger that costs more than the 15a charger i suggested.

 

[lw395]

Bit offensive isn't it?? The OP probably does understand but is just using non technical terminology. Cut some 'slack' yourself!

It's a technical subject. People who aren't prepared to take it seriously should leave well alone lest their boats catch fire.

 

[ghostlymoron]

Well said Peter. Some folks can get offensive when hiding behind the cloak of anonymity.

Bit offensive isn't it?? The OP probably does understand but is just using non technical terminology. Cut some 'slack' yourself!

 

[Graham376]

It's a technical subject. People who aren't prepared to take it seriously should leave well alone lest their boats catch fire.

Posters come here for advice, none of us knows everything about everything, although some seem to think they do There are ways of suggesting people are wrong and correcting mistakes, without creating offence.

 

[doug748]

As William_H has said, it does depend on usage as much as anything. Folk with large banks, who tend to flatten them down every trip, also like/need to charge them fast with powerful expensive chargers.

I fitted a fairly fancy, cheap, secondhand jobbie but rarely use it. Nice thing when I do is that it is mounted, securely, out of the way and it sorts out both banks on auto as soon as fired up.
I would carry on as you are at first.

 

[ghostlymoron]

+1

Posters come here for advice, none of us knows everything about everything, although some seem to think they do There are ways of suggesting people are wrong and correcting mistakes, without creating offence.

 

[CLB]

I've been on here for a lot longer than the join date above would indicate, pretty much since the beginning in fact, and back then it was much more about boaters helping each other. The OPs ignorance would have been met with helpful advice and a bit of useful education. Now it seems as if the place is rammed with self righteous know-it-alls who would rather belittle than help. Mixing up A and AH is quite common, almost normal, for non technical people when talking about battery sizes. It may be technically incorrect, but we all know what was meant and no boat is going to catch fire just because the wrong terminology is used in this instance.

What would be wrong with answering the question with some useful advice, if you really do know what you are talking about, and perhaps adding a bit of info about the correct way to talk about battery sizes?

 

[ghostlymoron]

I've been on here for a lot longer than the join date above would indicate, pretty much since the beginning in fact, and back then it was much more about boaters helping each other. The OPs ignorance would have been met with helpful advice and a bit of useful education. Now it seems as if the place is rammed with self righteous know-it-alls who would rather belittle than help. Mixing up A and AH is quite common, almost normal, for non technical people when talking about battery sizes. It may be technically incorrect, but we all know what was meant and no boat is going to catch fire just because the wrong terminology is used in this instance.

What would be wrong with answering the question with some useful advice, if you really do know what you are talking about, and perhaps adding a bit of info about the correct way to talk about battery sizes?

 

[ghostlymoron]

CLB I agree absolutely. I've been a member for several years and initially I was very glad of the advice I received, now I can occasionally give advice as well. It seems to be that there's a lot more animosity and downputting than there used to be which is a pity

I've been on here for a lot longer than the join date above would indicate, pretty much since the beginning in fact, and back then it was much more about boaters helping each other. The OPs ignorance would have been met with helpful advice and a bit of useful education. Now it seems as if the place is rammed with self righteous know-it-alls who would rather belittle than help. Mixing up A and AH is quite common, almost normal, for non technical people when talking about battery sizes. It may be technically incorrect, but we all know what was meant and no boat is going to catch fire just because the wrong terminology is used in this instance.

What would be wrong with answering the question with some useful advice, if you really do know what you are talking about, and perhaps adding a bit of info about the correct way to talk about battery sizes?