As far as I know, big trucks are still 12 volt, and most use 4 batteries.
_____ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Dale Leavens Sent: Sunday, November 11, 2007 11:48 To: [email protected] Subject: Re: [BlindHandyMan] series or parallel Well, you are directly shorting the batteries. Things would get really hot! You can draw 30 or 40 amps maybe more. If the connection positive to negative is a heavy enough wire then the resistance of the batteries would really heat them up. If not a really heavy cable the connection will heat maybe burn or smoke. A good 12 volt battery can supply a load of power. Two batteries used to be fairly common in diesel trucks, maybe still are. I am not sure but I think those might be 24 volt systems so the batteries would be connected in series in that case. Dale Leavens, Cochrane Ontario Canada [EMAIL PROTECTED] <mailto:DLeavens%40puc.net> net Skype DaleLeavens Come and meet Aurora, Nakita and Nanook at our polar bear habitat. ----- Original Message ----- From: Rob Monitor To: blindhandyman@ <mailto:blindhandyman%40yahoogroups.com> yahoogroups.com Sent: Sunday, November 11, 2007 11:57 AM Subject: Re: [BlindHandyMan] series or parallel What I'm asking this for is years ago I new a person the had a pickup truck with two batteries in it for starting in the winter in northern Minnesota when it gets 30-50 below zero... Just was wondering how you would hook the batteries up for that... Now here is another one for you if you took the batteries and hook them by positive to positive and negative to negative then put a wire between the positive and the negative of each battery what would that do??? ROB FROM MINNESOTA ----- Original Message ----- From: Dale Leavens To: blindhandyman@ <mailto:blindhandyman%40yahoogroups.com> yahoogroups.com Sent: Sunday, November 11, 2007 10:19 AM Subject: Re: [BlindHandyMan] series or parallel Hi Tom, Is that correct? I don't know myself but intuition would suggest to me that if the batteries were connected in parallel without the charger they would soon about balance each other. Once the charger is introduced the same conditions would apply, that is the weaker of the batteries would acquire charge faster than the other then together they would come up about equivalently wouldn't they? I think I would be concerned about the load on the charger though. Most would have a safety overload of some sort wouldn't they ? I haven't much experience with charging wet cells, as a kid we used to have to top up the battery in a couple of our boats that didn't have their own charging systems but that was about it. Oh yes, sometimes in the winter dad would put a charger on the car battery on those real cold nights to improve the chances it would start in the morning. Dale Leavens, Cochrane Ontario Canada [EMAIL PROTECTED] <mailto:DLeavens%40puc.net> net Skype DaleLeavens Come and meet Aurora, Nakita and Nanook at our polar bear habitat. ----- Original Message ----- From: Tom Fowle To: blindhandyman@ <mailto:blindhandyman%40yahoogroups.com> yahoogroups.com Cc: [EMAIL PROTECTED] <mailto:mred99%40means.net> net Sent: Sunday, November 11, 2007 11:00 AM Subject: Re: [BlindHandyMan] series or parallel rob, You'd do as you said, and that's parallel, but don't do it. If, as is very likely the batteries aren't exactly identically charged or discharged when you start, the current from the charger will be unevenly distributed between the batteries. This will almost certainly lead to uneven charging of the batteries, and if perhaps one battery is much more charged when you start than the other, you can get a very high current flow between the batteries and some pretty hot wires and batteries. there is no reason to even try this as even if it worked it would take twice as long to do the job, so you may as well charge the batteries seperaately and be safe. Again, charging two batteries from a charger designed for a single battery can be dangerous and has no advantage, so please don't do it. with led acid or similar batteries it is O.K. to parallel them for normal operation, re: running stuff as long as they're both charged properly seperately. It's not a good idea to parallel cells with nicad or nimh batteries either. tom Fowle Net-Tamer V 1.13 Beta - Registered [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
