6V Battery Banks

[raphaella]

Hello everybody,
We have a new batterie bank with 16 x 6volt t-106 batteries. We use solar to charge them. What is the normal maximum charge that we should program the controller? We use them as a 12 volt system using 24 volt solar panels but charging to 12 volts. Actually at the moment we charge them up to 14.7 but in 8 months have lost almost 1 cup of water in each cell, am I over charging? Thanks in advance, JP and Tania in need of helpé

[raphaella]

sorry t-105 batteries 6volt

[btrayfors]

Wow....16 T-105's. That's 1,800 amp hours total capacity @ 12VDC. Is this an installation in a house??

Re: charging, what you need is a good solar charge controller with adjustable charging profiles for different battery chemistries. I personally like the Morningstar MPPT controllers.

T-105's like to be charged at 14.8 or even 15.0VDC in the absorption cycle, at normal room temperatures. After receiving a full charge, T-105's like to be kept at about 13.2-13.4VDC float level, with periodic bumping up to absorption voltage for short periods of time.

I'd say that your water loss may not be excessive, but you can cut it down a lot by using either HydroCaps or WaterMiser caps. I use WaterMiser caps on all 10 of my T-105s. They make it easier to check water levels and to top them up.

Also, the new automatic watering system offered by Trojan is truly wonderful. It makes the job of keeping water levels properly maintained very easy and fast.

Bill

[skipmac]

Good question but really needs more information to answer correctly.

It will depend to some degree on how much you are drawing out of the batteries and how much solar capacity you have. If you had 1000 Watts of solar panels and draw very little from the batteries each day then 14.7V constantly could be too much.

But if you are using a lot of battery every day and only have a 150 Watts of solar then 14.7V should not be a problem.

[colemj]

Holy crap that is a big bank! Do you use over 1,000 AHrs each day? We are electricity hogs and we only have 6 T-105's.

Trojan recommends charging these batteries at 14.8V to absorption and holding there until float amperage input is reached.

However, this needs to be temperature compensated. Here in the tropics, the battery hold can easily be 90-100*, so the compensated charging voltage is often 14.4-14.5V instead.

At these temps and charging voltages, we need to add water to ours every 3 months or so, and the amount is much less than you are using - maybe 1/4 cup per cell (I use an outboard fuel line squeeze bulb to deliver water and it usually takes 1-2 partial squeezes of the bulb per cell).

Mark

[colemj]

Along those lines, if you are never drawing the batteries down much, and your solar charger has a fixed absorption time instead of variable, then you will be boiling them for several hours each day.

If this is the case, then your best solution is to get rid of half of your batteries. Or buy a solar controller that has a better algorithm. Or set yours to much shorter absorption times, if possible.

Mark

[raphaella]

Thanks a lot guys for all the info. And we do use much current, 2 fridges, 1 freezer and a new 12volt aircon unit being installed at this very moment. Never knew that making toasts used 92 amps on DC and with 6 daughters and 4 grandchildren, we need lots of toasts in the morning. Even thinking of getting a coffee maker. We do have a programmable solar MPPT controller and have adjusted to the proper settings with all your info and actually got in touch with Trojen where they were very helpful and gave all the technical data to my questions.

[raphaella]

Now for another question. Wind generator!! What kind is the most silent one and that actually charges well?

[raphaella]

Finally we installed a new silent wind and wow noise level lower than we expected! Yahoooo! Amps just under but that is the life. Only one thing after one month we realised that there was a little vibration that started. We simply washed the blades properly for dust particles started to stick to the ends of the blades, causing this vibration. Once washed vibration gone. Also do not forget to check the screws after a couple of weeks for they do loosen as mine did!!!

[Mike OReilly]

Originally Posted by raphaella

Finally we installed a new silent wind and wow noise level lower than we expected! Yahoooo! Amps just under but that is the life. Only one thing after one month we realised that there was a little vibration that started. We simply washed the blades properly for dust particles started to stick to the ends of the blades, causing this vibration. Once washed vibration gone. Also do not forget to check the screws after a couple of weeks for they do loosen as mine did!!!

Hi raphaella, I just noticed this thread. I installed a SilentWind generator last season, and have been very pleased with it so far. Very quiet, and seems to produce power pretty close to spec.

Thanks for the tips. I'll be sure to clean our blades before re-installing this season.

[mrm]

Originally Posted by raphaella

Finally we installed a new silent wind
[...] causing this vibration. Once washed vibration gone.

Also do not forget to check the screws after a couple of weeks for they do loosen as mine did!!!

Did you use a mild threadlocking compound on install? This is highly recommended on installing any parts which may vibrate.

[Formosa Scott]

edit: missed the last couple post before responding.

Take a look at Rutland wind generators, there are bigger ones out there but these are whisper quiet and start making power in relatively low wind. I don't don't have one but a friend has had one going for 4 years or so with no issues.

[zboss]

Originally Posted by mrm

Did you use a mild threadlocking compound on install? This is highly recommended on installing any parts which may vibrate.

Silentwind does not include or mention the use of a threadlocker on their blades, so we didn't use it either.

[mrm]

Originally Posted by zboss

Silentwind does not include or mention the use of a threadlocker on their blades, so we didn't use it either.

Nevertheless, next time you find some loose screws, try to apply some. It may (and likely will) make all the difference. I recommend a weak threadlock compound so screws can be undone with hand tools. Medium compound requires a substantial force to break, and strong one usually requires heat too.