What should I have done to get better service from my new batteries?

[Theo]

 

These are the ones I meant:

 

http://www.ebay.co.uk/itm/10A-DC-DC-600W-10-60V-to-12-80V-Boost-Converter-Step-up-Module-Power-Supply-UK-/350975904870

http://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_sop=15&_nkw=600w+dc+converter&rt=nc&LH_PrefLoc=1

 

They deal with up to 60V input so should be reasonably OK with spikes.

 

One thing to bear in mind with boost converters like these, if the output voltage is pulled *below* the input voltage, the current limit is disabled and it may blow the fuse on it. This is because there's a built in diode between input and output:

 

 

https://en.wikipedia.org/wiki/Boost_converter

 

So best to start when both sides are at the same voltage, and make sure the batts being eq'd are fully isolated.

 

You could go to semi-tractions like T105s, but more money and need eq current anyway, and - more of it too....

 

cheers, Pete.

~smpt~

 

I feel that I need to be a bit careful with this kit. Is this the way that I would use it:

 

0. Start with the bank fully charged

1. Disconnect half of the bank completely (+ve and -ve)

2. Connect the input side of the gizmo to the batteries that I have left in circuit to supply the boat electrics

3. Connect the output side to the batteries that I have disconnected. These batteries will themselves be connected in parallel. (How many batteries can I connect to the output? What voltage should I set on the output?)

4. Leave for some time (2hrs?)

 

Thanks for all the help.

 

N

[smileypete]

Sounds good, could just do a couple initially as a trial.

 

I'd expect the batts being eq'd only really need to have the positive isolated, as the unit almost certainly has a common connection between input -ve and output -ve like in the pic above, a multimeter will confirm.

 

Maybe set the output voltage to 15.5V or 16V if the batts are really cold. There's also a current control, once he batts are connected this could be adjusted down to give an output current of say 1amp per batt being eq'd, and the voltage should then slowly rise to the output voltage setting after which the current will slowly fall.

 

Might take a good number of hours, even repeating a few times if the batts are really bad. Maybe start it off on a sunny morning so the other batts can be kept charged in the mean time.

 

Sometimes the cover can be carefully prised off sealed wet leisures and so the SG checked, which would give an idea of how it's working. Failing that let the batts being eq'd rest for a good while and check the voltage, which should show some improvement after each session.

 

Bear in mind the batts being eq'd will gas a bit so take precautions like good ventilation and eye protection, some good safety info in The Battery FAQ (via google)

 

cheers, Pete.

~smpt~

Edited February 9, 2015 by smileypete

[Theo]

As my father used to say: "It's better to be born lucky than rich."

 

I have remaoved all of the rubbish SFLs and repaced them with Powersafe C90's. These are standby batteries which have been removed from a rack because the technicians forgot the 6 month recharge. In fact they are perfectly serviceable but the paperwork is not right for the application. I have 630Ah of then and installed them about ten days ago. They6 are working briliantly although they are in a situation for which they were not designed.

 

I am pretty confident that they will perform well for some years. The last lot (yes I had a similar lot new to me in 2008) lasted well until May last year (5 1/2 years) and even when I changed them they were nothing like as poor as the SFL's ended up. I now have to decide what deal I am going to strike with the supplier of the SFL's. He has already offered me a fair deal but I can't accept that because I don't want a set of batteries supplied by him.

 

I will let you know how longs this lot lasts on a CC boat.

 

Thanks again for all the hints and help.

 

Nick