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Re: Connecting batteries in parallel
Posted: 26 Mar 2011, 16:36
by The Bobdogs
Now a proper tightwad would probably have a 'contact' and only pay £25 a time for 110ah batteries, or possibly a daft aquaintance who was willing to part with 3 135ah batteries for £50...
I've got more batteries than Jordans bedside cabinet!!
Re: Connecting batteries in parallel
Posted: 26 Mar 2011, 20:04
by California Dreamin
The copper pipe trick sounds good but the vibration and movement in a camper is likely going to snap the rigid pipe connections around the terminals sooner or later....550amps touching the car body...ooooer!
Martin, as these batteries are just for the leisure circuit I doubt they are ever going to see more than 50 amps continuos with a possible 100amp peak but only for a few seconds from flat. The maximum the wiring is ever going to see (under normal conditions) is peak from the alternator (whats that on an old gal like this? 110 amp?)
so it's not like the starter battery that needs cables that can handle 220 amps? to crank that big beasty in to life.
25mm
2 170amp should easily do (thats 10mm OD, much smaller than your starter battery cable as they will never be cranking the engine, just delivering leisure current and being charged from a mains charger (20 amps leisure charger or alternator, 110 amps?) The cautionary note is the potential for much more current to flow IF there was ever a dead short. Personally I would fit a large (100 amp) fuse holder in there just in case.
http://www.autoelectricsupplies.co.uk/product/304" onclick="window.open(this.href);return false;
http://www.autoelectricsupplies.co.uk/product/752" onclick="window.open(this.href);return false;
I'll trump Andy's idea by suggesting a visit to Wacky Racers or Yabbadabbadoo's and picking up a couple of sets of cheapo jump leads (well the half decent ones) and canibalizing them for use.
If you fit this kind of battery clamp: the cables could be left continuos (depending on whether it would fit through the hole with it's insulation) these clamps are available in different sizes.
http://www.autoelectricsupplies.co.uk/product/113" onclick="window.open(this.href);return false;
Martin
Re: Connecting batteries in parallel
Posted: 28 Mar 2011, 18:15
by The Bobdogs
Re: Connecting batteries in parallel
Posted: 28 Mar 2011, 18:45
by 72BUG
We already have one, which is part of the reason why I need so many batteries.

Re: Connecting batteries in parallel
Posted: 28 Mar 2011, 21:40
by Red Westie
Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 16:36
by 72BUG
Job done!
Should get me through a few days roughing it at Proctors.

Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 17:41
by paulo999
Looks very tidy.
Please tell me you're now going to cap all those battery terminals.

Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 17:46
by 1664
Right, that's the cranking batteries sorted then.
Still let us know how you get on with the leisure batteries though...............
Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 17:51
by Mocki
i do hope there is a drop vent in that locker........ there will be quite a build up of gasses duriing charging in there now......
Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 19:01
by 72BUG
paulo999 wrote:Looks very tidy.
Please tell me you're now going to cap all those battery terminals.

Mocki wrote:i do hope there is a drop vent in that locker........ there will be quite a build up of gasses duriing charging in there now......
Not quite finished yet but what I'm thinking is putting a drop vent just in front of the batteries, then boxing the whole lot in so I can still use the locker for storage.

Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 19:17
by paulo999
Yeah, it was storage thing I was thinking of. It looks sufficiently inviting that something would get lobbed in, only to be lobbed straight back out, melting, in a shower of acid.
Boxing off would work.

Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 21:59
by Red Westie
Ayup Mart, looks like a great job you've done there...a vent is a good idea, so is boxing them in, I would also suggest some sorta strap (perhaps an old seatbelt), just in case. Brill job tho...can't wait to see you both.
Martin
Re: Connecting batteries in parallel
Posted: 30 Mar 2011, 22:55
by 72BUG
Red Westie wrote:Ayup Mart, looks like a great job you've done there...a vent is a good idea, so is boxing them in, I would also suggest some sorta strap (perhaps an old seatbelt), just in case. Brill job tho...can't wait to see you both.
Martin
Cheers Mart.
Can't wait mate. I think I'm stopping for a fortnight. Put the old bus through it's paces off tether and see what she can do if you 2 fancy popping back down when you break up

Re: Connecting batteries in parallel
Posted: 31 Mar 2011, 23:16
by 72BUG
Here's a thought. If I have my facts right then batteries give of hydrogen when charging, and hydrogen is lighter than air. So does that mean I ideally need the vent above the batteries rather than a drop vent in the floor?

Re: Connecting batteries in parallel
Posted: 01 Apr 2011, 08:52
by Mocki
yes it is lighter than air.... however proper leisure batterys have vent tubes, and i assumed they were proper leisure batterys, and so a drop vent would be ok as the gasses can only go where the tube takes them, down through the drop vent. This is one reason why you should have leisure batterys over normal cranking batterys.(although with a petrol t25 its mostly irrelvent as the cranking batttery is also in the living area anyway.
But lead acid batterys produce minimal hydrogen unless over charged, ie you keep charging when battery is at max.
have a read
here and