Wet cell batteries that don't need topping up. Something funny going on?

[TQA]

I am a full time liveaboard out in the Caribbean and it is really tough out here. Keeping the hydration level up is tough, well at least it was in the past. My previous two sets of batteries needed 2 to 4 pints of water every three to four weeks.

The current set were fitted on Nov 16th 2014, you will note that we were in commission, we guys out here don't get a winter break, we have to keep sailing, like I said it is tough out here.

So 6 brand new Trojan T 105 golf cart batteries went in 6 months ago. I pull the tops every month or so and see that they are fine. No topping is needed. However I broke down today and shared out a quart between the 6 even though they looked OK.

It is about 80f at this time of the year. [ Really tough ] They are cycled daily with the fridge drawing them down a bit overnight but the solar gets them back up in the typical sunny weather we have out here. I have equalized them 2 or 3 times.

Does anyone have any idea why this set don't use water?

 

[Mistroma]

My T105s don't use that much either but do use some. I have a dipstick marked to correct level and check every 6 weeks or so. I only add about 25mls to each cell to keep level up and that's around 450mls in total for 6xT105s. Temp tends to be around 30C a lot of the time and I usually cycle between 60%-85% with 100% every 2-3 weeks (marina visits).

I'd not be able to spot a 25ml difference in level but dipstick makes it easy (Trojan give correct level spec. in a PDF).
Why are you equalising the batteries? Do the individual cell SGs vary a lot? My cell SGs have never varied enough to warrant an eq. cycle in 3 years use (7 months use each year).

I hope that this helps.

 

[Niander]

Its so tough out there! ...make you wonder why they do it!...

 

[Birdseye]

I am a full time liveaboard out in the Caribbean and it is really tough out here. Keeping the hydration level up is tough, well at least it was in the past. My previous two sets of batteries needed 2 to 4 pints of water every three to four weeks.

The current set were fitted on Nov 16th 2014, you will note that we were in commission, we guys out here don't get a winter break, we have to keep sailing, like I said it is tough out here.

So 6 brand new Trojan T 105 golf cart batteries went in 6 months ago. I pull the tops every month or so and see that they are fine. No topping is needed. However I broke down today and shared out a quart between the 6 even though they looked OK.

It is about 80f at this time of the year. [ Really tough ] They are cycled daily with the fridge drawing them down a bit overnight but the solar gets them back up in the typical sunny weather we have out here. I have equalized them 2 or 3 times.

Does anyone have any idea why this set don't use water?

Batteries lose water through two processes - evaporation and hydrolysis. The latter being much more significant but it only applies when the voltage is getting to the gassing point and the battery is fully charged. Could be that your old batteries were tired, had lost capacity, were getting th=to the gassing point quickly, and your new ones are high capacity and maybe never getting to the point of being fully charged. Do you ever check charge levels with a hydrometer?

 

[Birdseye]

For some reason the editing function isnt working - I was going to try and clarify what I was saying.

You need to check that your new batteries are getting to the point of being fully charged and the only way to do this is with a hydrometer. In renewing your battery bank you have effectively increased battery capacity maybe eve doubling it since old batteries lose capacty throughout their lives. So it could well be that your charging system which was man enough to fully recharge the old batteries and even get them to the point where you were hydrolysing water is not man enough to get your new batteries back to full charge.
If your new batteries are getting fully charged and not using water then your system is working perfectly and you should be happy. Award yourself another rum punch.

 

[TQA]

For some reason the editing function isnt working - I was going to try and clarify what I was saying.

You need to check that your new batteries are getting to the point of being fully charged and the only way to do this is with a hydrometer. In renewing your battery bank you have effectively increased battery capacity maybe eve doubling it since old batteries lose capacty throughout their lives. So it could well be that your charging system which was man enough to fully recharge the old batteries and even get them to the point where you were hydrolysing water is not man enough to get your new batteries back to full charge.
If your new batteries are getting fully charged and not using water then your system is working perfectly and you should be happy. Award yourself another rum punch.

I do have a hydrometer but only use it when I suspect I have a dying cell. I think checking with a digital voltmeter is better, but it is a hassle as You need to disconnect and rest the cell before taking the voltage.

My charging is done with 400 watts of Solar coming through a Blue Sky MPPT controller. I see 20 to 26 amps charge rate. I am aware of the problem of getting the last 20% in, but I think it i doing the business.

My last set of Dekas used water from new. This set of T 105s don't. Just seems odd.

 

[RobbieW]

Dumb question perhaps; have they got recombinant caps fitted, Hydrocap or Water Miser are variants. If so, that may be your difference

 

[Mistroma]

What charging voltage are you using? Trojan spec. 14.8V for daily charge on T105s and 13.2V for float. If you as only reach around 14.4V then you'll probably use a lot less water.

 

[TQA]

What charging voltage are you using? Trojan spec. 14.8V for daily charge on T105s and 13.2V for float. If you as only reach around 14.4V then you'll probably use a lot less water.

Do Trojan batteries come with recombinant caps and what is my charging voltage? Heaves a sigh I guess it is RTFM time.

 

[Norman_E]

What charging voltage are you using? Trojan spec. 14.8V for daily charge on T105s and 13.2V for float. If you as only reach around 14.4V then you'll probably use a lot less water.

If that is the case, is it actually a problem? Batteries that get heavily discharged, then brought rapidly back to full charge on a regular basis tend to die faster than ones that get only partly discharged then gently recharged. Six batteries getting say 24 amps charge are only getting 4 amps each, which is gentle and should give good battery life provided that its enough to keep the voltage from dropping too low. An occasional recharge to full voltage using shore power should be enough to keep the battery bank happy, unless Trojan specify that they must be brought to 14.8 volts every time.

 

[GHA]

If that is the case, is it actually a problem? Batteries that get heavily discharged, then brought rapidly back to full charge on a regular basis tend to die faster than ones that get only partly discharged then gently recharged. Six batteries getting say 24 amps charge are only getting 4 amps each, which is gentle and should give good battery life provided that its enough to keep the voltage from dropping too low. An occasional recharge to full voltage using shore power should be enough to keep the battery bank happy, unless Trojan specify that they must be brought to 14.8 volts every time.

And there's a whole new (thread drift, soz ) can of worms. Batteries don't like not getting fully charged either, so is it better to get the voltage high to allow more chance of a full charge when the sun is out or be a bit gentler but risk not getting as much of a charge back in each day..

Back to the OP, batteries take quite a few cycles to "bed in" to full capacity when new, I wonder if they will gas a bit more after a few cycles? Or maybe it's just because you're used to more gassing as older batteries gas more.

A new deep-cycle battery will not deliver its full rated capacity. This is normal and should be expectedas it takes time for a deep-cycle battery to reach maximum performance or peak capacity.î Trojan’s batteries take between 50 – 100 cycles to work up to providing full, peak capacity

http://www.trojanbattery.com/pdf/TRJN0109_UsersGuide.pdf

 

[TQA]

My 6 are connected x 2 series to get 12 volts and x 3 to get 675 ah. Each Battery being 6v 225 ah.

So the charging rate is about 24/3 or approx 8 amps per cell.

My daily use is about 70 to 80 ah or less than 15% of capacity.

 

[RobbieW]

Do Trojan batteries come with recombinant caps...

They probably dont ex Trojan, your supplier may have fitted them as an added extra ?? They are a fairly common addition when using those batts in hot climates. Far as I can tell from pics online the 'standard' cell caps ex Trojan is a push in strip, recombinant would be individual caps for each cell which add something like an inch to the overall height.

 

[Mistroma]

Trojan T105s will be fitted with individual caps but they won't be recombinant type as standard, simply vent caps. They might fit push strips to their 12V range (T105s miles better life & value than those) but 6V range normally have caps.

Can of worms as someone said earlier. However, Trojan T105 specs. do quote expected cycles vs. depth of discharge. Unfortunately, you won't reach these figures (most people guess about 50%) as they are carried out under ideal circumstances.

I seem to remember that they do take about 50 cycles to develop full capacity and then drop of slowly afterwards.