Moving from 12v to 6v batteries?

[Mistroma]

Mistroma was talking about gases vented from the top, discolouring the boards above. For that issue, it doesn't matter how closely they're packed next to each other, just that there is airflow across the top of the bank.

I didn't fit fans to mine, but I did add a couple of louvred vents at each end of the locker to let air blow through.

Pete

Spot on, vent is across the top. I have Smartgauge/Smartbank and get controlled ventilation for price of a diode and some light wire. Inline computer fan runs at equivalent of 6V when charging starts and boosts to 12V near gassing voltage.

 

[Mistroma]

Your record keeping is exceptional

So go on then, what's a dry drip?

The lollipop stick with some sharpie marks works but it's been in the mental "must be a better way?" list for a while.

Wet dip is done by sticking the dipstick as far down as it will go and measuring the wet bit. Dry dip is the opposite as you measure the dry part between liquid and a fixed point at top of the vessel.

Kit is just a bit of plastic with T at the top and cut to correct length. I just push it in until the T rests on top and add water to reach the dipstick. I think that Trojan give the level as a distance below vent tube and you only need distance from there to top of the battery. Add both measurements and trim dipstick to length. You can use almost anything, I used a big matchstick with tape at one end (sticking out like a flag) as a trial system. Works but would need rinsing after each use.

 

[Mistroma]

Hmmm... so basically if I switch to 6v I need to have reasonable access to my batteries which I don't currently. Might need to do so rejigging to check them every 4 weeks. Just topped up with distilled water right? I,e water left overnight on the counter top?

Not certain what's meant by "water left overnight on the counter top".

 

[ghostlymoron]

Not certain what's meant by "water left overnight on the counter top".

Presumably so that chlorine evaporates.

 

[GHA]

Wet dip is done by sticking the dipstick as far down as it will go and measuring the wet bit. Dry dip is the opposite as you measure the dry part between liquid and a fixed point at top of the vessel.

Kit is just a bit of plastic with T at the top and cut to correct length. I just push it in until the T rests on top and add water to reach the dipstick. I think that Trojan give the level as a distance below vent tube and you only need distance from there to top of the battery. Add both measurements and trim dipstick to length. You can use almost anything, I used a big matchstick with tape at one end (sticking out like a flag) as a trial system. Works but would need rinsing after each use.

Thanks. I do have one then , lollipop stick with the sharpie mark til the water just forms a dimple as it kisses the stick. Just not as advanced as yours.

Ta

 

[Tim Good]

Presumably so that chlorine evaporates.

Correct. Or do I need to carry a supply of specialist water for top ups?

 

[lw395]

It seems silly to obsess about the minor advantage of changing to 6V batteries, then shorten their lives with dodgy water.
Deionised water is not that hard to find.
Failing that, if you are seriously off the beaten track, use melted frost from a freezer.

 

[GHA]

Correct. Or do I need to carry a supply of specialist water for top ups?

Pretty easy to find deionized water along the way, a few litres container should last a year. As for gaining access to the batteries, for a long and happy life your batts will be very glad of some tlc once a month or so. Checking and logging SG flags up any cells getting out of synch with the rest and is a good check for getting back to 100%

 

[Tim Good]

So I enquiried with a reputable battery company about Trojan T105 close to the location of my boat. He asked what I wanted them for so I told him my plans and current setup. Here is what was said. It seem sensible. What do you think?

----------------

It would generally be considered a backward step. Apart from additional maintenance, the batteries are also prone to gassing and potentially spillages. Furthermore you would need to keep distilled water onboard to top them up.

I would definitely recommend AGM Batteries. They are fully sealed and completely maintenance free for the duration of their life, (bar charging).

They also have a much much lower internal resistance compared to a Trojan traction battery and will therefore charge more quickly when exposed to solar charging. You will require less sun to achieve the same state of charge.

These batteries are significantly less prone to gassing since they internally recombine. (they only vent through a pressure release valve if over-charged).

Your Victron MPPT can easily be configured to charge AGM, as can your onboard charger. (Trojan Traction batteries require higher charge rates, and need to gas in order to move the electrolyte within the batteries to prevent stratification of the acid. (essentially the heavier acid sinks to the bottom of the batteries and erodes the plates). This gassing process is a necessary part of the charging cycle in order to ensure a reasonable life. With an AGM battery the electrolyte is fixed in situ and held in place with a glass matting so stratification cannot occur.

AGM batteries are very robust, unlike a gel, which has a fussier charging regime and is damaged more easily through over-charging.

Trojan batteries are very good, however I find they perform better in applications when there is a known discharge and charge cycle. For instance a floor scrubber or golf buggy. They are discharged to a pre-determined level, then recovered immediately on a mains powered charger. In this application it would be difficult to justify the additional costs of AGM (although many have now swapped to agm).

Ok, so you have a fairly common flooded starter battery being used as a domestic/leisure battery. You'll note they are actually designated "starter" on the top of the battery, and also it shows the CCA @ 750, which is reference to its starting prowess.

They can withstand some cycling, due to their relatively heavy duty construction, however they are certainly not ideal.

I keep an AGM battery in stock which would be a direct replacement for those. This would mean you could utilise the existing cables, connections, battery boxes etc with no modifications whatsoever. I have absolutely no doubt that in your particular scenario they will comfortably outperform the Trojan T105.

These batteries are £148.27 each plus vat. I will also allow you £10 per battery against your old batteries if they are traded against them, since we return scrap monthly.

 

[GrahamM376]

I keep an AGM battery in stock

One of the first lessons for retailers - always try to sell ex stock and the product with the best margin. Seems most liveaboards with practical experience are wrong

P.S. Unless he's changed his view recently, Charles Sterling, who designs more chargers and alternator boosters than most, recommends open lead acid.

 

[GHA]

So I enquiried with a reputable battery company about Trojan T105 close to the location of my boat. He asked what I wanted them for so I told him my plans and current setup. Here is what was said. It seem sensible. What do you think?

----------------

For most boats which post on here probably a fair bit of sense in what he says. Long distance cruising I disagree, T105's will put up with a load of abuse, make a mistake with charging or if the regulator throws a wobbly then you could well be stuffed a very long way from being able to get a decent replacement with AGM's. As you might have got the feeling, I very much like as simple as possible for important systems off the beaten track

This site is well worth a the cost of a years sub IMHO, even if you don't agree with eveything he says. Lots of great info in the comments as well -

https://www.morganscloud.com/2010/08/02/agm-battery-test-part-1/

He likes AGM , partly as they have such a big daily consumption & need to get loads back in fast.

 

[RobbieW]

....
He likes AGM , partly as they have such a big daily consumption & need to get loads back in fast.

Wet cell batteries generally have a recommendation to charge (in amps) at C/4 or 5, AGMs can usually be charged at Cx4 (where C is capacity in amp/hours). Its all a balance between cost, capacity, usage and charge rates.

 

[Plevier]

So I enquiried with a reputable battery company about Trojan T105 close to the location of my boat. He asked what I wanted them for so I told him my plans and current setup. Here is what was said. It seem sensible. What do you think?

----------------

It would generally be considered a backward step. GENERALLY? Apart from additional maintenance, the batteries are also prone to gassing and potentially spillages. Furthermore you would need to keep distilled water onboard to top them up. TRUE (IF YOU WILL BE IN REMOTE PLACES)

I would definitely recommend AGM Batteries. They MAKE MORE MONEY FOR ME, are fully sealed and completely maintenance free for the duration of their SHORTER life, (bar charging).

They also have a much much lower internal resistance TRUE compared to a Trojan traction battery and will therefore charge more quickly when exposed to solar charging. You will require less sun to achieve the same state of charge. PROBABLY NOT SIGNIFICANTLY, THIS BENEFIT REALLY ONLY SHOWS UP AT HIGH CHARGE RATES E.G. ON ENGINE CHARGING

These batteries are significantly less prone to gassing since they internally recombine. (they only vent through a pressure release valve if over-charged).TRUE

Your Victron MPPT can easily be configured to charge AGM, as can your onboard charger. (Trojan Traction batteries require higher charge rates DISPUTED, and need to gas in order to move the electrolyte within the batteries to prevent stratification of the acid. (essentially the heavier acid sinks to the bottom of the batteries and erodes the plates). This gassing process is a necessary part of the charging cycle in order to ensure a reasonable life. With an AGM battery the electrolyte is fixed in situ and held in place with a glass matting so stratification cannot occur. STRATIFICATION IS UNLIKELY TO OCCUR IN A BATTERY OUT ON THE OCEAN WAVE!

AGM batteries are very robust, unlike a gel, which has a fussier charging regime and is damaged more easily through over-charging. MORE ROBUST THAN GEL, LESS THAN T-105

Trojan batteries are very good, however I find they perform better in applications when there is a known discharge and charge cycle. For instance a floor scrubber or golf buggy. They are discharged to a pre-determined level, then recovered immediately on a mains powered charger. In this application it would be difficult to justify the additional costs of AGM (although many have now swapped to agm). THAT IS INDEED WHAT THEY WERE DESIGNED FOR AND IS THE MAJOR MARKET. I DON'T THINK ANYONE HAS PRODUCED AN AGM THAT WILL STAND UP TO THIS APPLICATION AS WELL I.E. GIVE THE SAME CYCLE LIFE

Ok, so you have a fairly common flooded starter battery being used as a domestic/leisure battery. You'll note they are actually designated "starter" on the top of the battery, and also it shows the CCA @ 750, which is reference to its starting prowess.

They can withstand some cycling, due to their relatively heavy duty construction, however they are certainly not ideal.

I keep an AGM battery in stock which would be a direct replacement for those. This would mean you could utilise the existing cables, connections, battery boxes etc with no modifications whatsoever. I have absolutely no doubt that in your particular scenario they will comfortably outperform the Trojan T105. OUTPERFORM IN WHAT RESPECT? NOT IN CYCLE LIFE.

These batteries are £148.27 each plus vat. I will also allow you £10 per battery against your old batteries if they are traded against them, since we return scrap monthly.

People talk about AGM as though that's all you need to know. The truth is there are rubbish AGMs and very good ones, ones which are for high rate and ones which have reasonable cycle lives.
Caveat emptor.

 

[GrahamM376]

Wet cell batteries generally have a recommendation to charge (in amps) at C/4 or 5, AGMs can usually be charged at Cx4 (where C is capacity in amp/hours). Its all a balance between cost, capacity, usage and charge rates.

Unless I'm misreading this, if I replace my Trojans with 480ah of AGM and want to charge quickly, where can I get a 1920 amp charger or space to fit enough panels?

 

[Mistroma]

People talk about AGM as though that's all you need to know. The truth is there are rubbish AGMs and very good ones, ones which are for high rate and ones which have reasonable cycle lives.
Caveat emptor.

+1
OP is asking specifically about T105s and alternative seems to be AGMs of unknown spec. and difficult to compare.

A friend with a large HR spent about 5,000 euro on expensive AGMs and had to bin them after a year. He left them charging over winter and charger developed a fault. I think it was always on boost. I had pointed out higher financial risk with money he was going to spend. T105s might have survived, probably not, but their loss would have been easier to bear. He didn't buy AGM second time around.

 

[RobbieW]

Unless I'm misreading this, if I replace my Trojans with 480ah of AGM and want to charge quickly, where can I get a 1920 amp charger or space to fit enough panels?

Should have said up to The point I was trying to make is that, for some, (good deep cycle) AGMs may be worth it if your usage requirement justifies it and you've more charging capacity than OLAs would use. If you've 400ah of OLA theres little point in having a charging system capable of more than about 100A. However, if you use 100A+/day you'd want to fully recharge every couple of days then it might be worth looking at AGM & a high cap alternator

 

[Mistroma]

So I enquiried with a reputable battery company about Trojan T105 close to the location of my boat. He asked what I wanted them for so I told him my plans and current setup. Here is what was said. It seem sensible. What do you think?

----------------

It would generally be considered a backward step. Apart from additional maintenance, the batteries are also prone to gassing and potentially spillages. Furthermore you would need to keep distilled water onboard to top them up.

I would definitely recommend AGM Batteries. They are fully sealed and completely maintenance free for the duration of their life, (bar charging).

They also have a much much lower internal resistance compared to a Trojan traction battery and will therefore charge more quickly when exposed to solar charging. You will require less sun to achieve the same state of charge.

These batteries are significantly less prone to gassing since they internally recombine. (they only vent through a pressure release valve if over-charged).

Your Victron MPPT can easily be configured to charge AGM, as can your onboard charger. (Trojan Traction batteries require higher charge rates, and need to gas in order to move the electrolyte within the batteries to prevent stratification of the acid. (essentially the heavier acid sinks to the bottom of the batteries and erodes the plates). This gassing process is a necessary part of the charging cycle in order to ensure a reasonable life. With an AGM battery the electrolyte is fixed in situ and held in place with a glass matting so stratification cannot occur.

AGM batteries are very robust, unlike a gel, which has a fussier charging regime and is damaged more easily through over-charging.

Trojan batteries are very good, however I find they perform better in applications when there is a known discharge and charge cycle. For instance a floor scrubber or golf buggy. They are discharged to a pre-determined level, then recovered immediately on a mains powered charger. In this application it would be difficult to justify the additional costs of AGM (although many have now swapped to agm).

Ok, so you have a fairly common flooded starter battery being used as a domestic/leisure battery. You'll note they are actually designated "starter" on the top of the battery, and also it shows the CCA @ 750, which is reference to its starting prowess.

They can withstand some cycling, due to their relatively heavy duty construction, however they are certainly not ideal.

I keep an AGM battery in stock which would be a direct replacement for those. This would mean you could utilise the existing cables, connections, battery boxes etc with no modifications whatsoever. I have absolutely no doubt that in your particular scenario they will comfortably outperform the Trojan T105.

These batteries are £148.27 each plus vat. I will also allow you £10 per battery against your old batteries if they are traded against them, since we return scrap monthly.

Check battery megastore or Tayna for prices. I've even seen further discounts for ordering 4,6 or 8 batteries. You might get T105s for 2/3 price quoted for AGM. Not enough detail to say for certain, but 8xT105 seems excessive.

 

[Mistroma]

Presumably so that chlorine evaporates.

Why not boil it to reduce the volume and increase concentration of inorganics even more?

Trojan give a good list of things likely to shorten battery life (Chloride ions are but one of many on their list). Practically every supermarket in med. sells deionised/demineralised water.

 

[Tim Good]

People talk about AGM as though that's all you need to know. The truth is there are rubbish AGMs and very good ones, ones which are for high rate and ones which have reasonable cycle lives.
Caveat emptor.

How is it possible to determine "very good ones". To get specific this is the type this chap recommended. It wasn't battery mega store but I'm posting the link for ease:

https://www.batterymegastore.co.uk/marine-batteries/deep-cycle/hankook-ax31-950.html#productCollateralTabs1

 

[GrahamM376]

if you use 100A+/day you'd want to fully recharge every couple of days then it might be worth looking at AGM & a high cap alternator

Couple of points - We try never to use the engine just for charging, it runs when we're going somewhere. Even if the engine is used, standard alternator regs won't allow high enough voltage to take advantage of larger size unless Sterling/Adverc booster fitted. Our 70 amp alternator very rarely outputs more than 35 amps and regulated to 14.2v. Have a Honda 20i for charging if needed.

I was persuaded some years ago to install Exide Enersols, which are supposed to be the mutts nuts for solar use. Very expensive and lasted 3 years, just the same as so-called leisure. If someone wants to go for AGM that's fine with me but, most of the liveaboards I know use Trojan mainly because of performance but also availability anywhere without mixing battery types.