Newbie...Trojan t105

[WotEver]

 

Yes still using the dodgy Samartgauge, but the 24.4V value is obtained from the BMV702 which agrees with my multimeter. I rarely look at the Smartgauge voltage.

 

(My other smartgauge is in the other boat in Rugby and a series of unexpected obstacles have prevented me driving up to get it.)

Rugby isn't too far from me. Send me the keys in that package you're going to send me and I can go get it for you and post it back

[MtB]

Lol no I haven't forgotten the package. Thing is, I need the oscilloscope, a jiffy bag, the stamps, the time to do it, and the thought of doing it. All these conditions need to be present concurrently.

 

As some perceptive bloke once said... "Ladies, if a man says he'll do something, he'll do it. There is no need to keep reminding him every six months..."

 

But who was it?!

[cuthound]

Lol no I haven't forgotten the package. Thing is, I need the oscilloscope, a jiffy bag, the stamps, the time to do it, and the thought of doing it. All these conditions need to be present concurrently.

 

As some perceptive bloke once said... "Ladies, if a man says he'll do something, he'll do it. There is no need to keep reminding him every six months..."

 

But who was it?!

Don't know, but he got the timescale wrong. Mrs Hound reminds me something like every 6 minutes if she thinks it is important

[Leon 12]

Ok.... Batteries update.

 

Performed charge until tail read 4.58 amps fluctuating slightly..(took 3 hours). Then perforformed equalization charge at 15.5 volts..(actually 15.43 at battery posts) for 5 hours. First thing I noticed all cells were bubbling differently, the post which was directly connected to charger (first in line so to speak) was bubbling great guns ,the rest were all different. The battery at the opposing corner was hardly doing anything. At the end of the equalization charge all cells were even in bubbling. Next a weird one..... ( if anyone has had any battery liquid on their fingers and forgot and placed said hand in mouth....yak). Well at first not strong.....at the end it was strrrroooooongggg. Yes your thinking crazy fool. Also one thing I have noticed on my tracer since installing that even though voltage was high the little battery emblem showing capacity would always be low.....mmmm. This time the emblem shall we say was at a steady 80% after resting for 30 mins. Everything turned off. Voltage crept down from 15.5 to 13.00 ran fridge to remove surface charge. My conclusion is this, at time of purchase those batteries could have been stood on shelf for a while, I didn't perform a charge until a long while after install even though they had two 100 solar panels connected but the setting were left on factory. No voltage setting reconfigured to trojan requirements . So a little knowledge was bad. I have changed the tracer to fit with what trojan say ( placed slightly higher for the cold and voltage drop from busbar connection. 15.1 absorption 13.9 float. 16.2 equalisation.

Tail current on equalisation charge dropped to 7.5 amps, over the next hour it stopped dropping so ended the charge. How many more charges of this nature will I have to perform to try to get the lost capacity back. The specific gravity read the same across all 18 cells.

[WotEver]

How many more charges of this nature will I have to perform to try to get the lost capacity back. The specific gravity read the same across all 18 cells.

If they were mine I'd gently take them down to 30% as indicated by Smartgauge and then immediately charge up to 100% as indicated by tail current. I'd do this two or three times. Then I'd check capacity.

 

Tony

[Leon 12]

How does the tail voltages appear to be ....in my last post. Regarding a 675 amp hour bank.....capacity unknown.

[nicknorman]

How does the tail voltages appear to be ....in my last post. Regarding a 675 amp hour bank.....capacity unknown.

Do you mean the tail current? If so yes at less than 1% it represent "pretty well fully charged". But the point is that if the batteries are significantly sulphated, this takes a long time to convert back to acid and lead and whilst the process is going on you probably won't see a reduction in charge current. It's simply not really the same process as normal charging. You can't determine when to stop equalising by looking at the tail current, you have to measure the specific gravity of all the cells and compensate the readings for temperature. When all the cells are at the 25 centigrade equivalent of 1.277 or thereabouts, with electrolyte levels near the nominally full level (ie as supplied) then you can be confident that the equalisation process has stopped making any difference and you can stop it.

[MtB]

Ok.... Batteries update.

 

Performed charge until tail read 4.58 amps fluctuating slightly..(took 3 hours). Then perforformed equalization charge at 15.5 volts..(actually 15.43 at battery posts) for 5 hours.

 

 

Errr, don't the Trojan instructions say equalise at 16.0V?

[WotEver]

The tail current at less than 1% becomes irrelevant anyway if we don't know the charge voltage, and it wasn't stated. Trojan recommend a finishing voltage of 16.2V which is pretty much unattainable with most chargers but nevertheless I'd want to see a nice low tail current with a charge voltage in excess of 15V at these temps.

 

Other than that, what Nick said. Only a temperature compensated Relative Density reading can tell us how sulphated the batteries are.

 

A couple of good deep discharges each immediately followed by a charge to 100% will help.

[Leon 12]

If you know of any chargers that give out 16.2 volts on an equalisation charge let me know. The sterling gives out 15.5 volts, that is the charge current I applied for 5 hours which resulted in tail current of 7.5 amps. Could stratification be the cause with my undercharging and low discharges?

[MtB]

With my cynical hat on, I wonder if Trojan specify a 16.2v finishing charge because they know there are no chargers on the market that do this.

[WotEver]

If you know of any chargers that give out 16.2 volts on an equalisation charge let me know. The sterling gives out 15.5 volts, that is the charge current I applied for 5 hours which resulted in tail current of 7.5 amps. Could stratification be the cause with my undercharging and low discharges?

No, it's not stratification. Not if the cells were all bubbling nicely.

 

7.5A at 15.5V would suggest pretty close to 100%.

 

As for the charger, why not give Charles Sterling a call? If you find him in a good mood he might be able to suggest something.

 

With my cynical hat on, I wonder if Trojan specify a 16.2v finishing charge because they know there are no chargers on the market that do this.

I guess an email to Trojan asking where to buy this mythical charger that they recommend wouldn't hurt

[MtB]

I guess an email to Trojan asking where to buy this mythical charger that they recommend wouldn't hurt

 

 

I predict no answer....

[Leon 12]

My hydrometer has a thermometer on the front, after the charge was finished it read 1.285 across the board, the thermometer indicated an eight point deduction due to temp. Which gave 1.277. As I wrote earlier the electrolyte wasn't strong to taste at first ( albeit by accident) but after charge it was defo strong. Maybe a daft way to test. am i wrong but surely that is what an equalisation charge does to some degree, mix the electrolyte up. Also to remove some sulphation,if its not too far gone.

I did get a few answers from trojan even if they were not too explanatory .

[WotEver]

My hydrometer has a thermometer on the front, after the charge was finished it read 1.285 across the board, the thermometer indicated an eight point deduction due to temp. Which gave 1.277. As I wrote earlier the electrolyte wasn't strong to taste at first ( albeit by accident) but after charge it was defo strong. Maybe a daft way to test. am i wrong but surely that is what an equalisation charge does to some degree, mix the electrolyte up. Also to remove some sulphation,if its not too far gone.

I did get a few answers from trojan even if they were not too explanatory .

If you're seeing 1.277 on all cells then that's great. Balanced cells with little sulphation. Now you just need to exercise the batteries a few times to get them up at full capacity.

[Leon 12]

Exercise??? Is that make them work or take them down to a deeper discharge. What would you recommend ? When I rang Tayna he said 12 volts is trojan at 50 %

[WotEver]

 

Yes an equalisation charge will as a by-product mix up the electrolyte nicely. The reason it becomes stronger is because you're converting all the sulphate back into acid - that is all you're doing when you charge a battery. Equalisation balances the cells by giving them a timed over-charge and at the same time converts some of the hardened sulphate crystals that the standard charge left behind.

Exercise??? Is that make them work or take them down to a deeper discharge. What would you recommend ? When I rang Tayna he said 12 volts is trojan at 50 %

As I said earlier, take them down gently to 30% on the Smartgauge and then recharge back to 100% as measured by tail current. Do it at least twice.

 

Tanya are wrong if they told you 12V is 50%. It's more like 40%.

 

Here's the user guide again http://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf

[nicknorman]

Whilst it sounds good that you are getting a nominal 1.277 I'll just mention that Trojans do have quite a large volume of electrolyte above the plates. When the cells bubble they are losing only water, not sulphuric acid. So if the electrolyte level is correct ( 1/8" below the well IIRC) that's great. But if the electrolyte level is only just above the plates that means that quite a bit of water has fizzed off and the sulphuric acid is less diluted. So a reading of 1.277 with low electrolyte level might mean the batteries are yet to be fully desulphated.

[WotEver]

Whilst it sounds good that you are getting a nominal 1.277 I'll just mention that Trojans do have quite a large volume of electrolyte above the plates. When the cells bubble they are losing only water, not sulphuric acid. So if the electrolyte level is correct ( 1/8" below the well IIRC) that's great. But if the electrolyte level is only just above the plates that means that quite a bit of water has fizzed off and the sulphuric acid is less diluted. So a reading of 1.277 with low electrolyte level might mean the batteries are yet to be fully desulphated.

A very good point. Leon, did you top up before taking the readings?

[MtB]

A very good point. Leon, did you top up before taking the readings?

 

 

I topped up before taking readings once, and the readings were all amazingly close to 1.000.

 

Quelle surprise...

[WotEver]

I topped up before taking readings once, and the readings were all amazingly close to 1.000.

 

Quelle surprise...

Okay, top up then charge for another 10 mins and THEN take a reading

[Leon 12]

The electrolyte was full, they haven't lost any. Will top up if required in future.

[cuthound]

The tail current at less than 1% becomes irrelevant anyway if we don't know the charge voltage, and it wasn't stated. Trojan recommend a finishing voltage of 16.2V which is pretty much unattainable with most chargers but nevertheless I'd want to see a nice low tail current with a charge voltage in excess of 15V at these temps.

Other than that, what Nick said. Only a temperature compensated Relative Density reading can tell us how sulphated the batteries are.

A couple of good deep discharges each immediately followed by a charge to 100% will help.

Excellent advice front Tony and Nick.

 

I too wonder where Trojan get the 16.2 volts from. That is 2.7 volts per cell, and I seem to recall from my "on the tools" days, that the maximum charge voltage is 2.67 volts per cell, which for a 6 cell (12 volt) battery would be 16.02 volts.

 

Perhaps the 16.2 is missing a "0"?

 

Equalising at 15.5 volts will do no harm, it will just take a little longer. It is the dual action of the cell heating up and the gassing of the electrolyte that breaks down the sulphation.

 

Edited to add the last paragraph, coz I'm suffering from premature posting

Edited February 20, 2017 by cuthound

[nicknorman]

Excellent advice front Tony and Nick.

I too wonder where Trojan get the 16.2 volts from. That is 2.7 volts per cell, and I seem to recall from my "on the tools" days, that the maximum charge voltage is 2.67 volts per cell, which for a 6 cell (12 volt) battery would be 16.02 volts.

Perhaps the 16.2 is missing a "0"?

 

No I think they mean 16.2, the figure occurs in several places. However that is the upper limit, not necessarily the target. See this charging profile diagram:

 

 

So 14.7 to 16.2v for the "finishing voltage"

Edited February 20, 2017 by nicknorman

[dmr]

 

 

Errr, don't the Trojan instructions say equalise at 16.0V?

 

I am pretty sure that Trojan specify different voltages depending upon which or their documents you are reading, I am sure one of them says 15.5v.

 

................Dave