Numax m110 batteries

[Justme]

 

Wonder what Gibbo's ideal max charge current to battery bank amphour ratio is, as a balance between charging time & battery life.

 

Again its not that simple.

 

A big charger with a short bulk phase will need a longer absorb phase than a small charger & longer bulk phase. Over the full recharge cycle the total charge time will be similar. So a small genny running at near on full duty cycle could use less fuel over the full charge than a big one that tapers off nearer the end.

 

Ideally you need a big charger that runs on a paid for fuel but running at or near capacity & them a smaller one that runs for free (IE PV) or for cheap on a smaller genny. Switch over as soon as the charge falls to the level the smaller charger can supply.

 

Not many can afford or find space for a two genny system.

[WotEver]

Again its not that simple.

Indeed: http://www.smartgauge.co.uk/chargesize.html

 

Tony

[nb Innisfree]

Wonder what Gibbo's ideal max charge current to battery bank amphour ratio is, as a balance between charging time & battery life.

 

I would think that if you take the ideal charge rate as 1amp per 1% of DoD of battery bank capacity then unless you are prepared to watch and constantly reduce throttle setting to limit charge level you need something in the region of 20-25% of capacity, so that when batts reach approx 80% SoC they start to reduce charge so will not receive excess charge rate below that point.

[by'eck]

Indeed: http://www.smartgauge.co.uk/chargesize.html

 

Tony

 

Sorry forgot to check that out.

 

Having read the article it seems that that the 150 amp max charge current available from either engine or shore power should be about right (for me at least) with a 550Ah service bank.

 

I note JustMe's comments but was looking at a best compromise, with the time of bulk phase being the most relevant here. The absorb phase will take much the same time whatever the capacity of charger.

[Gibbo]

Another take on this is to have a high capacity charger in relation to battery bank size, say 100 amp charger or alternator serving a 400Ah battery bank.

 

The engine/alternator or generator/charger is then working for the minimum amount of time. Downside is battery life, but a similar balance of costs can be sought.

 

The problem is, as the batteries get into a higher state of charge, it simply won't be possible to put that much current into them.

 

Wonder what Gibbo's ideal max charge current to battery bank amphour ratio is, as a balance between charging time & battery life.

 

A rule of thumb for wet cells is you can put back in, in amps, the same number as the number of amp hours that need replacing. So a 100ahr battery, at 90% SOC can take 10 amps. At 85% SOC, it can take 15 amps, at 50% it can take 50 amps and so on.

 

It's a pretty good estimate for wets. It doesn't work at all for gel or AGM.

 

I would think that if you take the ideal charge rate as 1amp per 1% of DoD of battery bank capacity then unless you are prepared to watch and constantly reduce throttle setting to limit charge level you need something in the region of 20-25% of capacity, so that when batts reach approx 80% SoC they start to reduce charge so will not receive excess charge rate below that point.

 

Yes.

 

There is actually a device in development to calculate and display all this stuff. It's horribly complicated, a huge amount of work, and if a commercial version is ever released it will be horribly expensive. Simply because it's so complicated.

[nb Innisfree]

The problem is, as the batteries get into a higher state of charge, it simply won't be possible to put that much current into them.

 

 

 

A rule of thumb for wet cells is you can put back in, in amps, the same number as the number of amp hours that need replacing. So a 100ahr battery, at 90% SOC can take 10 amps. At 85% SOC, it can take 15 amps, at 50% it can take 50 amps and so on.

 

It's a pretty good estimate for wets. It doesn't work at all for gel or AGM.

 

 

 

Yes.

 

There is actually a device in development to calculate and display all this stuff. It's horribly complicated, a huge amount of work, and if a commercial version is ever released it will be horribly expensive. Simply because it's so complicated.

 

I seem to recall a 'discussion' between you and a certain former poster on a device to sense SoC and reduce charge accordingly?

[Gibbo]

I seem to recall a 'discussion' between you and a certain former poster on a device to sense SoC and reduce charge accordingly?

 

Myself and several colleagues in the States worked on this about 15 years ago. We achieved it in the lab, and the reduction in charge times was dramatic. However there were some major practical problems that meant it simply wasn't viable as a commercial product. Still isn't.

[kebilli]

I have had the same problem with Numax, also with a leasure battery you only take them down to 50% discharge, any lower than that and you will damage the battery. 2 years ago I bought 4 105 amphr Trogan deep cycle batteries off the internet, these you take down to 20%. We live aboard our boat and during the Sping/Summer we go off for about 5/6 months cruising. I have had no problem at all, in fact in the information book that comes with them it teels you how to look after them and it also states that after several discharge/recharges they will improve their performance, they have. I have two 70 amp alternators with Stirling regulators, when out cruising I will use about 100 amps overnight, telly, fridge etc, when I run the engine next morning it puts about 95 amps in, it takes about two and a half hours to fully charge them again, I am well pleased with them. Just google Trogan, they cost about £130 each and are a similar size to 110 leasure Batteries.

[alan_fincher]

Just google Trogan, they cost about £130 each and are a similar size to 110 leasure Batteries.

If you Google "Trogan batteries" rather unsurprisingly Google says.....

 

Do you mean Trojan Batteries.

 

I think at least some of your references to "amps", like discharging batteries in the evening, are probably meant to be to "amp hours" ?

[Gibbo]

[nb Innisfree]

I have had the same problem with Numax, also with a leasure battery you only take them down to 50% discharge, any lower than that and you will damage the battery. 2 years ago I bought 4 105 amphr Trogan deep cycle batteries off the internet, these you take down to 20%. We live aboard our boat and during the Sping/Summer we go off for about 5/6 months cruising. I have had no problem at all, in fact in the information book that comes with them it teels you how to look after them and it also states that after several discharge/recharges they will improve their performance, they have. I have two 70 amp alternators with Stirling regulators, when out cruising I will use about 100 amps overnight, telly, fridge etc, when I run the engine next morning it puts about 95 amps in, it takes about two and a half hours to fully charge them again, I am well pleased with them. Just google Trogan, they cost about £130 each and are a similar size to 110 leasure Batteries.

 

Can I ask how how you know your batteries are full? It takes at least several hours to fully charge a battery, there's no other way alternator controllers or not, if you stay in bulk charge then power used can be replaced quickly but once acceptance voltage is reached then progressively more power has to be used to replace power used.

 

Also the 50% rule is a level of discharge that generally gives the most economical balance between cost of fuel used and replacement of batteries, it doesn't mean that no damage is done if go to 52% SoC but does damage to go to 48% SoC, it's damaging at any level of discharge just more damaging the deeper you go.

Edited September 9, 2011 by nb Innisfree

[Gibbo]

Over the next couple of weeks I'm going to do a full document explaining, with mathematical details, the 50% rule so that people can understand where it comes from and why it applies.

[by'eck]

Just google Trogan, they cost about £130 each and are a similar size to 110 leasure Batteries.

 

Beware of the 12 volt Trojan batteries as many are not true deep cycle despite being sold as such. The SCS225 for example at 130Ah has same footprint as Numax but have a CCA quoted suggesting they are dual purpose starter/leisure batteries. I didn't find them very durable.

 

Six volt T105 225Ah golf cart batteries seem most popular with the US boat cruising brigade when fitted in pairs, although you may consider the T145 at 260Ah with same footprint but taller.

[bottle]

I have had the same problem with Numax, also with a leasure battery you only take them down to 50% discharge, any lower than that and you will damage the battery. 2 years ago I bought 4 105 amphr Trogan deep cycle batteries off the internet, these you take down to 20%. We live aboard our boat and during the Sping/Summer we go off for about 5/6 months cruising. I have had no problem at all, in fact in the information book that comes with them it teels you how to look after them and it also states that after several discharge/recharges they will improve their performance, they have. I have two 70 amp alternators with Stirling regulators, when out cruising I will use about 100 amps overnight, telly, fridge etc, when I run the engine next morning it puts about 95 amps in, it takes about two and a half hours to fully charge them again, I am well pleased with them. Just google Trogan, they cost about £130 each and are a similar size to 110 leasure Batteries.

 

 

 

kebilli

 

I think that maybe some reading would be of use.

 

http://www.batteryfaq.org/

 

and

 

http://www.smartgauge.co.uk/ (click on 'technical info' at the top)

[smileypete]

I have had the same problem with Numax, also with a leasure battery you only take them down to 50% discharge, any lower than that and you will damage the battery. 2 years ago I bought 4 105 amphr Trogan deep cycle batteries off the internet, these you take down to 20%. We live aboard our boat and during the Sping/Summer we go off for about 5/6 months cruising. I have had no problem at all, in fact in the information book that comes with them it teels you how to look after them and it also states that after several discharge/recharges they will improve their performance, they have. I have two 70 amp alternators with Stirling regulators, when out cruising I will use about 100 amps overnight, telly, fridge etc, when I run the engine next morning it puts about 95 amps in, it takes about two and a half hours to fully charge them again, I am well pleased with them. Just google Trogan, they cost about £130 each and are a similar size to 110 leasure Batteries.

At last! Someone who understands what deep cycle batts are all about!

 

Beware of the 12 volt Trojan batteries as many are not true deep cycle despite being sold as such. The SCS225 for example at 130Ah has same footprint as Numax but have a CCA quoted suggesting they are dual purpose starter/leisure batteries. I didn't find them very durable.

In what way? How were they charged?

 

cheers,

Pete.

Edited September 11, 2011 by smileypete

[by'eck]

At last! Someone who understands what deep cycle batts are all about!

 

 

In what way? How were they charged?

 

cheers,

Pete.

 

The Trojan SCS 225 mentioned only lasted me three years, although I'm sure the golf cart ones would have faired better. Other brands have lasted six or seven treated the same, being regularly fully charged by engine, generator or shore power.

 

I found their characteristics were such they never had a clear cut-off point when fully charged, continuing to draw current causing gassing & therefore needing regular topping up of electrolyte.

 

All the other brands/types I've used had a clear point at which the charge taken dropped to a bare minimum in float mode & requiring less maintenance. Best ones I had were Freedom Lead/Calcium. I only replaced them because they were six years old & Walmart in the US had a special offer on.

 

I charged them at up to 14.9 volts, but when fully charged the current dropped to less than an amp when float mode reached. They were discharged below 50% SOC during the vagaries of an Atlantic crossing but continued to give service for another three years.

[smileypete]

The Trojan SCS 225 mentioned only lasted me three years, although I'm sure the golf cart ones would have faired better. Other brands have lasted six or seven treated the same, being regularly fully charged by engine, generator or shore power.

 

I found their characteristics were such they never had a clear cut-off point when fully charged, continuing to draw current causing gassing & therefore needing regular topping up of electrolyte.

Doesn't sound too good. Were you able to check the S.G.(specific gravity) anytime, if so what sort of reading did you get?

 

With flooded deep cycle batts a good way of keeping them topped up is with an automatic watering system.

 

cheers,

Pete.

[Evo]

Getting away from automatic battery watering systems for a minute, (holy crap).

 

Where are we with "Who sells a decent battery these days".

 

 

1) A pseudo deep cycle, leisure, 'starter battery with handles'. (is there a decent one..!!)

 

2) a longish lasting reasonably priced propper deep cycle battery designed for marine use (there must be one..!)

 

3) The ultimate 'you cant go wrong with these babies if you've got a big enough wallet' battery.

 

Can anyone identify the best battery to go for for 1,2,and 3 scenarios.

[Justme]

3 must be the bats that Gibbo is testing.

[smileypete]

Getting away from automatic battery watering systems for a minute, (holy crap).

 

Where are we with "Who sells a decent battery these days".

 

 

1) A pseudo deep cycle, leisure, 'starter battery with handles'. (is there a decent one..!!)

 

2) a longish lasting reasonably priced propper deep cycle battery designed for marine use (there must be one..!)

 

3) The ultimate 'you cant go wrong with these babies if you've got a big enough wallet' battery.

 

Can anyone identify the best battery to go for for 1,2,and 3 scenarios.

1) Any reasonable quality non sealed truck or leisure batt.

 

2) The 6 volt ~220Ah batts eg US Battery US2200XC, Trojan T105, and Crown CR225, subject to 3) below.

 

3) You can certainly go wrong even with the very best batts, if they're not charged and maintained as the makers recommend. They might even work pretty well but OTOH might not be as good as expected.

 

There are others like AGM and sealed flooded batts, although they don't need maintenance, they still need charging in the way the makers recommend.

 

Anyway in my opinion a 'proper deep cycle batt' is one that can be discharged to 20% with little or no cost penalty.

 

cheers,

Pete.

Edited September 12, 2011 by smileypete

[Bob Blues]

I just put US2200 in and when I googled the info from www.windsun.com there is a chart that seems to go a lot firther than what is posted on here. ie

State of Charge 12 Volt battery

100% 12.7

90% 12.5

80% 12.42

70% 12.32

60% 12.20

50% 12.06

40% 11.9

30% 11.75

20% 11.58

10% 11.31

0 10.5

 

is this a good set of figures?

[blodger]

I just put US2200 in and when I googled the info from www.windsun.com there is a chart that seems to go a lot firther than what is posted on here. ie

State of Charge 12 Volt battery

100% 12.7

90% 12.5

80% 12.42

70% 12.32

60% 12.20

50% 12.06

40% 11.9

30% 11.75

20% 11.58

10% 11.31

0 10.5

 

is this a good set of figures?

Might be a bit misleading for open lead acid batteries where 12.2v represents 50% charged IIRC

[WotEver]

The little chart I keep to hand (including SG readings) for a 'typical' LA battery is this:

 

100% 1.265 12.7

75% 1.225 12.4

50% 1.190 12.2

25% 1.155 12.0

0% 1.120 11.9

 

 

Tony

[Evo]

1) Any reasonable quality non sealed truck or leisure batt.

 

2) The 6 volt ~220Ah batts eg US Battery US2200XC, Trojan T105, and Crown CR225, subject to 3) below.

 

3) You can certainly go wrong even with the very best batts, if they're not charged and maintained as the makers recommend. They might even work pretty well but OTOH might not be as good as expected.

 

There are others like AGM and sealed flooded batts, although they don't need maintenance, they still need charging in the way the makers recommend.

 

Anyway in my opinion a 'proper deep cycle batt' is one that can be discharged to 20% with little or no cost penalty.

 

cheers,

Pete.

 

 

 

For me as a leisure weekend boater then my option 1)'s are OK. I had sort of deduced that as I dont have the cycle requirements of a liveaboard.

 

But if you live aboard really you need option 2/3 batteries.

Where do you get them from..?? How much are they...?? How inconvenient are they to fit - if previously boat had 4 std 110's.

Anyone got a link to a place that sells these things - with prices.

[WotEver]

Anyone got a link to a place that sells these things - with prices.

Take a look earlier in this thread - Posts 56 onwards for type 3, then some recommendations for type 2.

 

Tony

 

Post #75 for a good type 2