alahol2
Well-Known Member
OK.
Batteries won't float...
- Thread starter tyce
- Start date
OK.
pvb
Well-Known Member
The real answer is "ideally not". I reckon engine start batteries should be dedicated to engine starting - nothing else. That way, the engine is usually likely to start.
PaulRainbow
Well-Known Member
Ah the old "selective quoting" trick.
You actually said
I already told you why it's a bodge. You are ignoring the fact there is an issue with the domestic battery voltages, again.
Not only is it a bodge, it's a potentially dangerous bodge. If there are low voltage problems with banks of batteries there could be serious fault with one battery in th bank pulling down the voltage of all of the batteries in that bank. This can often lead to excess gassing of the faulty battery and a very real a risk of explosion.
I have seen several instances where a single battery was gassing badly enough to set the Co alarms off. This is serious stuff, posing a significant risk of explosion, which can cause life changing injuries.
The underlying issue with the domestic batteries must be investigated.
PaulRainbow
Well-Known Member
Of course, i'm talking nonsense and batteries don't really explode, or do they ?
boat battery exploded - Google Search
car battery exploded - Google Search
But hey, no-one ever get injured, or do they ? Try a Google search for that one, some pretty horrible injuries, mostly from tiny batteries in phone or e-cigs. Imagine what a large leisure battery or two would do to you ? You won't just have the explosion and flying chunks of battery to deal with, you have chemical burns too. Your eye balls don't much like battery acid.
boat battery exploded - Google Search
car battery exploded - Google Search
But hey, no-one ever get injured, or do they ? Try a Google search for that one, some pretty horrible injuries, mostly from tiny batteries in phone or e-cigs. Imagine what a large leisure battery or two would do to you ? You won't just have the explosion and flying chunks of battery to deal with, you have chemical burns too. Your eye balls don't much like battery acid.
tyce
Well-Known Member
When i installed the b2b i didnt want it on the engine battery incase of a fault with it. I can live with it flattening the house battery but would rather the engine started when asked.
Interestingly as mentioned I had a fault this year on my starter battery, middle of the night on mains supply the CO alarm went off waking the family up, thought it was a dodgy alarm as nothing was running, went back to bed. Next night it did the same but we also woke with irritated throats, lifted the engine compartment and the fumes were very strong.
The starter battery was to hot to touch and gassing badly, turned the power off left it an hour and then got the battery off the boat. No long term effects but certainly a lesson learned.... never doubt a CO alarm.
Interestingly as mentioned I had a fault this year on my starter battery, middle of the night on mains supply the CO alarm went off waking the family up, thought it was a dodgy alarm as nothing was running, went back to bed. Next night it did the same but we also woke with irritated throats, lifted the engine compartment and the fumes were very strong.
The starter battery was to hot to touch and gassing badly, turned the power off left it an hour and then got the battery off the boat. No long term effects but certainly a lesson learned.... never doubt a CO alarm.
Beneteau381
Well-Known Member
Nearly happened to me! One bad un fooled the charger in to keeping charging when it had started boiling, I went below and smelt it, it was hot enough to burn my hand!
VicS
Well-Known Member
But the b 2 b should not run the battery flat. Its designed to only cut in when the battery is being charged and to cut out again when its not
VicS
Well-Known Member
I asked if there was any reason not to power the B2B from the starter battery
I asked you for a technical explanation as to why it should not be powered from the starter battery...
I am still waiting for you to give that that technical explanation. Can't I guess
A fault in one battery in any multiple battery/ multiple bank installation charged by a high output multi stage charger can pull the voltage of all the batteries in the bank down with a risk of excessive gassing and even explosion regardless of whether or not there is a B2B charger connected .
How many of the examples in your Google searches were directly attributed to an incorrectly connected B2 B charger?
You've been Googling too much again
PaulRainbow
Well-Known Member
Your original questions and my replies are both at the bottom of this post. AS you can see from the text highlighted in red, your question regarding B2B connection was answered there. It was also answered in subsequent posts.
Indeed it can and as i have said, more than once, this has nothing to do with the B2B connection. It has to do with your ignoring the issues with the domestic bank, moving the B2B to the engine battery may well allow the B2B charger to charge the thruster battery but at the expense of ignoring the real issue and leaving the OP with a potentially dangerous battery fault.
For your convenience, i have highlighted the answer to the other part of your original questions in blue.
I would wager very good money that not one single example was caused by an incorrectly connected B2B charger, but lets not forget, i have never said it is incorrect to connect a B2B charger to the engine battery, again, see red text below.
I would also wager than a great many of the examples were caused by faulty batteries, where the problems had not be addressed.
As for Googling, i have simply provided evidence of battery explosions. Unlike you, i don't need to use Google for my answers, my replies come from personal knowledge, real World experience.
Now might be a good time to put the spade away.
[/quote][/quote]
pvb
Well-Known Member
No, it shouldn't run the start battery flat. But what if the B2B charger becomes faulty and runs the battery flat? Keeping the engine start battery isolated for its prime purpose is still the best way.
VicS
Well-Known Member
That is the OPs reasoning for connecting to the house bank
I was wondering why use a B2 B charger anyway ... why not just use a VSR .?
pvb
Well-Known Member
A B2B charger allows the cable to the thruster battery to be thinner, as the current is controlled.
PaulRainbow
Well-Known Member
When using the bow thruster the engine will be running, therefore the VSR will be closed. Bow thrusters have a huge current draw and if the thruster battery is partially discharged it will try and draw power from the domestic bank, chances are, it will blow the fuse in the VSR circuit. It isn't good practice to use a VSR for this application.
VicS
Well-Known Member
So you would chose one with a relatively low current rating in order to keep the cable down. Makes sense .
tyce
Well-Known Member
Thought I would update this with my findings for those that are interested.
Swapped the batteries around and when the house battery's were connected to the engine leads they went straight to 13.8v which is the correct float voltage. From this its clear the charger has a problem.
So... I popped the front off the charger and unbeknown to me it is a 3 outlet charger and I only need two so swapped the outlet to the spare one and low and behold success. Good result as its cost nothing.
It did get me wondering if I am over cooking things with my newly installed B2B charger which is a Sterling 60A charger. Is it coincidence that the charger packed up or is the B2B's high charge capacity causing issues with the 240V only giving 20A? Cant see why a high load on the batteries would cause an issue with the charger though. Any ideas.
Swapped the batteries around and when the house battery's were connected to the engine leads they went straight to 13.8v which is the correct float voltage. From this its clear the charger has a problem.
So... I popped the front off the charger and unbeknown to me it is a 3 outlet charger and I only need two so swapped the outlet to the spare one and low and behold success. Good result as its cost nothing.
It did get me wondering if I am over cooking things with my newly installed B2B charger which is a Sterling 60A charger. Is it coincidence that the charger packed up or is the B2B's high charge capacity causing issues with the 240V only giving 20A? Cant see why a high load on the batteries would cause an issue with the charger though. Any ideas.
Beneteau381
Well-Known Member
My sterling, the book says that if the third outlet isnt used, to connect the adjoing two together
pvb
Well-Known Member
Why did you choose a 60A B2B charger? Seems an expensive option just to keep a thruster battery topped up. Regardless, if you only put 20A into it, you won't get more than 20A out, and you won't damage it.
Incidentally, in your original post you said the B2B charger needs 13.6v to start charging, but Sterling's literature says 13.3v.
pvb
Well-Known Member
The OP has a Dolphin charger.
tyce
Well-Known Member
Went with the 60A as Sterling sell them at a very good price reconditioned on eBay, it was actually quite a bit cheaper than the lower rated one if bought new. They didn't have lower rated reconditioned units.
Yes you are correct its 13.3V, the Dolphin was charging to 13.36V which should have charged the other bank but when the B2B kicked in it dragged it below 13.3. With the correct float voltage it keeps the house bank at circle 13.6V.
Like you say, I guess initially 60A will come out of the batteries initially until they are dragged down a bit and then it will all settle down at the 20A being supplied from the Dolphin. I guess what has happened is a sign the charger is past its best but it is 14 year old so if I get a few more years without the hassle and expense of wiring in a new one then alls good.
Yes you are correct its 13.3V, the Dolphin was charging to 13.36V which should have charged the other bank but when the B2B kicked in it dragged it below 13.3. With the correct float voltage it keeps the house bank at circle 13.6V.
Like you say, I guess initially 60A will come out of the batteries initially until they are dragged down a bit and then it will all settle down at the 20A being supplied from the Dolphin. I guess what has happened is a sign the charger is past its best but it is 14 year old so if I get a few more years without the hassle and expense of wiring in a new one then alls good.
Elessar
Well-Known Member
On the charger that is
Electrics aren't my strongest point so Im looking for some advice.
My 2x110ahr leisure batteries whilst sat on the mains charger are only reaching 13.3v, not a massive problem except I have installed a battery to battery charger for the thruster that needs 13.6v to kick in.
The manual for the charger (Dolphin All in One 12v 20A) states float voltage as 13.8V. The engine battery which comes off a different feed from the same charger is reaching 13.8V but not the house batteries.
So im not sure if its the charger or the battery's, I guess the way to confirm it is swap leisure and start battery around but does anyone on here know if its likely to be the charger or battery that is at fault?
Ive been through 3 sets of batteries. And this week I found the problem. Which probably means I've thrown away £££ of good batteries. Or ruined them.
I had 2 wiring errors and a set up fault.
Charger is a sterling power digital thing with 3 outputs. Fitted by the previous owner.
The 2 outputs went to the domestic and engine batteries. The 3rd was unconnected. The instructions say (id never read them) that if you only have 2 outputs connected you have to connect 2 outputs together and connect to one battery and connect the 3rd output to the second battery. That upped the voltage by 1/2 volt.
Then the DIP switches were set to the wrong battery type. That upped it by another 1/2 v.
At this point my "broken" drinks fridge started to work!
Finally i didn't know that when you parallel batteries with all the link cables you have to connect the -ve cables (to the boat) to the battery at the end of the run and the +ve cables to the battery at the other end of the run, Mine were all connected in the middle of the battery bank.
my 1000CCA battery which was testing as 200CCA "replace battery" is back to nearly 900CCA and "good battery" in 2 days.
A good day's work.