Posted by waltd on February 19, 01 at 11:55:46:
In Reply to: Re: Size Matters posted by Marty on February 18, 01 at 22:14:28:
I even take it a step further:
I have a second battery in my vehicle, that is Isolated by a 200 amp continuous duty relay. I always attempt to jump start the dead vehicle using only my secondary battery with the secondary battery totally isolated from my vehicle .
I also have another relay that feeds a "quick disconnect" on the front of my vehicle from the secondary battery. My jumper cables plug into the disconnect. (this is all part of the WARN Multimount system, which is also for my wench - I have plugs front and rear)
The end result is that I get to plug everything in "cold" and then energize the jumper cables by a dash mounted switch. This just energizes the jumper cables, but doesn't tie the secondary battery to the rest of the vehicle. I don't even lift my hood, or get anywhere near my batteries.
I use an Optima Yellow top in both the primary and secondary battery positions, which is enough to start most any vehicle on the road. If I want to, I can tie both batteries together with the engine on or off, giving me double the starting power.
When I go to disconnect, again I can turn the power to the jumper cables off, so that I only have to worry about clamps on the vehicle that needed a jump start.
Here are a few more things:
- Since I have an Optima Yellow top, it doesn't mind being run down a little, I'll usually try to give the dead battery vehicle as much juice as time will allow. Especially if it is known why their battery went dead (lights on, etc) vs some other electrical problem. This saves their alternator from trying to be a battery charger, which most aren't!
- If I know my secondary battery is run down quite a bit, I only let my alternator charge it for a few minutes and then give the alt. a rest. (Cycle the Relay on and Off) This prevents alternator burn-out on my vehicle. Or, if I know all be home soon, I just leave it off and charge it up with a battery charger off house current.
- If I run my primary battery down (rare on my new vehicle), I am sure to bring the secondary on-line to help out the alternator, or better yet, disconnect the primary all together, using only the secondary good battery.
- Alternators are reasonable battery maintainers and a good source of power to run the vehicle and accessories. Unfortunately, they aren't good at running at full capacity cotinuously, and they aren't smart enough to avoid burning themselves up (which is what happends if you try to make them charge a totally dead battery- especailly that upgraded maga battery.)
Just my 2 cents
Walt