Moderators: User administrators, Moderators
kevtherev wrote:Edmundson Electrical
Rexel Senate
City Electrical Factors (C.E.F.)
These companies usually have trade counters and deal with large cable, wire and give good advice.
I would use 10mm copper.
unless B&Q do it
Red Westie wrote:As others have said....a large bank of batteries can be difficult and often troublesome to keep. The issue is around keeping all the cells equally charged and the damage one failed battery can do to the other good ones.
There are ways to minimize the problems, special charges, diodes but all very expensive.
If you are set on connecting them all in parallel then charge them individually from time to time, check the specific gravity of each cell routinely (the most accurate way of checking charge state and an early indicator of a failing...dead cell) 1.280 SG = full charge ---- 1.150 SG flat.
The actual leasure amp draw is probably alot lower than you might think but the worry for me would be connecting these to the existing split charge system and the FRIGHT! that circuit is going to get after 3-4 days without mains.
It might also be a good idea to have a Maxi fuse between each battery in case of one having an internal short.
Martin....whats going to be charging these on mains....and same question, when running?
Martin
California Dreamin wrote:OK....so the jiggery pokery (mains) is going to effectively 'trickle charge (slow charge) this mass of cells. I say slow charge because even a heafty 16 amp unit split over 5 batteries (30 cells) 550ah is only tickling the cells but as a 'constant' this isn't a bad thing. Ideal charge is generally regarded as being 1 tenth the amp hour value (55amp) but I can't see your RV having anything like that, I'm guessing 20amps at best.
How sophisticated this charger is (whether it is staged and turns on to float charge when it senses full charge state) either way there will be a lot of constant activity and the cells will use a fair amount of water (depending on what type you have bought). Good old fashioned lead/acid cells which have removable caps may use more water but at least the cells can be topped up and maintained.
The weak pont will be the amount of 'initial' current demand put on the alternator after those five batteries have been run down. At least by your description there is a mechanical switch 'engaging' the split charge circuit, this is a positive as the wiring is likely more robust.
I think we also have to bare in mind that this is a humungous RV that must have been prepared (designed) for such use, so all the associated circuits and switches must be man enough for the job.
Martin
Andy, Julie, & Bobdog wrote:Right then...this is how the the insane do it....Assuming battery terminals are the threaded type.
Put your batteries in a row and measure the distance between the outside terminals. (say 750mm for example) .
Go to plumbers merchants and buy twice this length of 15mm copper pipe.
Beat it flat with big hammer.
Drill holes in copper to line up with battery terminals.
Tape up the rest of the copper with pound shop electrical tape...one red, one black.
Bolt positives together with the red one and the negatives together with the black one .
You have now made one big battery.
Keep it charged with cheapo charger from halfords (£50) that has voltage display and can be left permanantly connected.
Use and abuse for 2 to 3 years then replace batteries as they will be about shot and cheapo new ones are only about £80 a go.
Been working perfectly on the boat for the last god knows how many years...
Give me a ring mate if you want more bad advice from someone who actually uses this kit day to day.....
Loads of info on the boating forums about this too.
kevtherev wrote:yep sounds good to me
then when they are shagged get the traction batteries, you wont need as many either.... tight wad
