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Trojans behaving Badly


dmr
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We better meet up for a few beers at the Waterfront then, in addition to teaching you electronics looks like we need to do some Greek Mythology too!

 

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

 

Actually I was attempting a rather crude double entendre... :D

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Actually I was attempting a rather crude double entendre... biggrin.png

 

We actually did put them over our heads once upon a time. Then inflated them via our my noses with our hands holding them around the back of our heads and around our cheeks. On wild drunken nights in the mess, it was called 'franging'. The more advanced method was to use a rubber glove, so that you ended up looking like a rather unwieldy chicken. Happy days.

  • Greenie 1
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Actually I was attempting a rather crude double entendre... biggrin.png

 

That's not really a double entendre.

THIS is a double entendre:....

 

"Woman walks into a bar and asks for a double entendre so the barman gave her one"

 

That's possibly my all time favourite joke. I realise this is off topic but now that we know that people read these technical threads for entertainment we have to do our best.

 

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

  • Greenie 1
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That's not really a double entendre.

THIS is a double entendre:....

 

"Woman walks into a bar and asks for a double entendre so the barman gave her one"

 

That's possibly my all time favourite joke. I realise this is off topic but now that we know that people read these technical threads for entertainment we have to do our best.

 

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

 

That's now gone to all my WhatsApp contacts! Greenie.

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I was expecting a reduction in capacity but was surprised at just how much it was.

The fridge might perhaps have taken a bit extra overnight to get back down to its correct temperature, but not enough to get down to 65%.

The low tail current and charging imbalance both surprised me.

It was all rather unfortunate that after this mild winter we chose to go away just when the cold snap came on, and also left the boat in a well known K&A cold spot!

 

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

 

Dave,

 

Have the batteries improved as the temperatures have risen?

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Been on holiday for a week, left boat with batteries (6 Trojans in 12 volt bank) just about 100% charged, isolators off, and possibly small input from small solar panels.

Whilst away recorded -12degC outside and -6 inside, possibly a bit lower than -6 at batteries.

 

Returned home, Smartgage read 100%.

Turned isolators on, within 15 mins Smartgage down to 98%.

Did big engine run early evening. After a while charge tail current down to 4 amps, this is very low, normally see about 12.

Next morning Smartgage read 65%, would have expected about 80% to 85%.

 

Another engine run and measured charge current in each of three battery pairs. Noted significant variation: 27, 24 and 20 amps approx. but this improved as charge progressed.

Did very short equalisation

Batteries appear to now be recovering.

Any good ideas as to what is going on?

My only thought is stratification.

 

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

 

 

Maybe they are pee'd off that you didnt take them on holiday with you? Are they sensitive souls?

 

Tim

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We better meet up for a few beers at the Waterfront then, in addition to teaching you electronics looks like we need to do some Greek Mythology too!

 

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

Mythology?! It's history.

 

N

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Mythology?! It's history.

 

N

Quite right!

 

But sadly, like too many members these days ............................

 

What IS wrong with a bit of gentle humour - we all know life's tough enough?

Edited by metanoia
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That's not really a double entendre.

THIS is a double entendre:....

 

"Woman walks into a bar and asks for a double entendre so the barman gave her one"

 

That's possibly my all time favourite joke. I realise this is off topic but now that we know that people read these technical threads for entertainment we have to do our best.

 

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

 

 

Yeahbutnobut Sir, it WAS a double entendre, read it again!

(Not as good as yours though, obviously. I've always like that joke too ever since I was a teenager!)

P.S. Gideon Coe is playing some good music on R6 tonight :)

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I was expecting a reduction in capacity but was surprised at just how much it was.

The fridge might perhaps have taken a bit extra overnight to get back down to its correct temperature, but not enough to get down to 65%.

The low tail current and charging imbalance both surprised me.

It was all rather unfortunate that after this mild winter we chose to go away just when the cold snap came on, and also left the boat in a well known K&A cold spot!

 

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

 

 

Smelly Bridge?

 

(or maybe Brass knocker, but no pub nearby...)

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Quite right!

 

But sadly, like too many members these days ............................

 

What IS wrong with a bit of gentle humour - we all know life's tough enough?

 

I've tried that with many of my posts here and there, but they don't see to attract much reaction. A mirthless lot, by and large. Either that, or my sense of humour isn't right!

 

Keep trying though, eh.

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I've tried that with many of my posts here and there, but they don't see to attract much reaction. A mirthless lot, by and large. Either that, or my sense of humour isn't right!

 

Keep trying though, eh.

 

 

Yes me too. It worries me how often something I say in a feeble attempt at humour gets taken literally, or 'straight' by someone or other.

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Are we going to bring this thread back on topic then?

 

 

Daniel

 

 

Didn't we conclude the reason was the SG didn't know the temperature of Dave's had fallen to -6o while he was on holiday and the SG was rather confused by this?

 

Normal service appears to have resumed since waking up the boat and the SG has re-learned what batteries it is connected to!

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Yes me too. It worries me how often something I say in a feeble attempt at humour gets taken literally, or 'straight' by someone or other.

Frequently I suspect, each has there own sense of humour, and when face to face can see whether it is a joke or not. The written word carries none of that interaction thus treat as a joke and it is not wrong, so it gets treated seriously.

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Smelly Bridge?

 

(or maybe Brass knocker, but no pub nearby...)

 

Left the boat at Honeystreet Wharf for the week. The long pound between Wilcot and Honeystreet is always cold and windswept, but now the Barge is closed its even colder; just don't get the radiation from the flying saucers.

 

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

 

Maybe they are pee'd off that you didnt take them on holiday with you? Are they sensitive souls?

 

Tim

 

Would have done but there was no room in the car, it was either the dog or the batteries and the dog would have made much more trouble.

And yes, my batteries are obviously very sensitive that's why I have to look after them! I wonder if a shot of rum into each cell would make them happy.

 

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

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Didn't we conclude the reason was the SG didn't know the temperature of Dave's had fallen to -6o while he was on holiday and the SG was rather confused by this?

 

Normal service appears to have resumed since waking up the boat and the SG has re-learned what batteries it is connected to!

 

We're getting told off by the modes so need to get back on topic.....

 

I hope you are not moving to the dark side (smartgage knockers)

I did say that a quick voltage check suggested the smartgage was correct.

Batteries are now back to normal, 70% this morning and did not run the engine at all yesterday, though this is in part because Gillie is away so not sucking the life out of them with her computer games.

 

The battery box and engine are at 6 degrees this morning (can't be bothered to lift the lid to get directly to the batteries) and the lowest recorded cabin temperature whilst away was -6. I don't think that would be enough to explain the reduction in capacity that I saw.

 

This quantifies the temperature effect:

http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

 

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

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This quantifies the temperature effect:

http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

 

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

However I suggest it is a bit like Peukert, rather misleading for boat applications. When the batteries are cold, there is the same amount of chemicals to react and thus the same number of electrons to be migrated, the reaction just happens more slowly. Ultimately there is the same capacity available if you discharge slowly. But of course in terms of a battery's spec, capacity at C20 say, a cold battery will reach its terminating voltage sooner than a warm one and thus the effective capacity at a constant C20 is reduced. However if you took that ostensibly flat battery and either warmed it, or left it to recover and then discharged slowly, you could recover the remaining charge. The charge is not lost in cold weather, it's just hibernating like all sensible things!

 

Edited by nicknorman
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We actually did put them over our heads once upon a time. Then inflated them via our my noses with our hands holding them around the back of our heads and around our cheeks. On wild drunken nights in the mess, it was called 'franging'. The more advanced method was to use a rubber glove, so that you ended up looking like a rather unwieldy chicken. Happy days.

you have just taken me back years, i was posted to osnabruck for 3 months having just done 3 plus years supporting the sas. the 5 field force infantry were 3 para and the naafi was out of bounds to crap hats [non cherry berry soldiers], not knowing this and it was my first day there i went in to be greeted by a load of condom heads and chickens. i survived only because i had sas wings badges on [they are different to para ones] and an invite to dine there when ever i wanted sick.gif

doesnt smart gauge have a temp sender that lives with the batteries like my nasa bm2. my midnite solar controller has one as well more wires going to the batteries than a little

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...doesnt smart gauge have a temp sender that lives with the batteries like my nasa bm2. my midnite solar controller has one as well more wires going to the batteries than a little

No, it doesn't need one. The rested voltage vs SoC graph only has a very slight temperature co-efficient, no enough to bother with. Your solar controller needs one because the optimum charging voltage changes a lot with temperature. I can't immediately think why a nasa bm2 would need one.

 

Edit: according to the nasa bm2 manual I've just looked at, there is no temperature probe.

Edited by nicknorman
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doesnt smart gauge have a temp sender that lives with the batteries like my nasa bm2. my midnite solar controller has one as well more wires going to the batteries than a little

Nope. The bold bit is one of the reasons why not - SmartGauge is designed to be very simple to install, being aimed at the non-technical boater. The other reason is that it doesn't require one for its stated purpose. Dave did post that the voltage on the battery terminals supported SmartGauge's stated SoC figure.

 

Tony

I can't immediately think why a nasa bm2 would need one.

Me neither. Are we sure it has one?

 

Tony

 

ETA - Nick beat me to it - looks like the BM-2 doesn't have one.

Edited by WotEver
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Further reading shows that you can enter a battery temperature manually into the bm2, in steps of 10C, however this is used for the "time to run at the current current" parameter for the reasons I mentioned earlier. The Smartgauge doesn't have a "time to run" parameter and so it doesn't need to know temperature, and thinking about it, since it doesn't measure current it wouldn't need it even if it did.

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