Battery question

[Bill O'Donovan]

I've been carrying a spare battery with 720 amps for several years, recharging periodically. Now I'd like to change it out with my twin batteries of 625s, so that it gets some use and regular recharging.Is it okay to mix a 625 with a 720? If not, and I simply use the one 720 as a substitute for the twins, I assume I change my switch to "Battery 1." But what do I do with the dangling second red cable?

 

[Ed Schenck]

Looking forward to the. . .

right answer Bill. When I was going to add a battery to my house bank, one identical to two already there, it was suggested that I not. The company rep said you should not mix a new battery with old batteries. Don't understand the real reason but I guess something to do with different charging rates. And I don't know if this applies in your case.I assume one would be on switch #1 and the other switch #2. If you never used "BOTH" there could not be a problem. But then you would have to work out some way to charge both from your charger and alternator. I do that with a West combiner.

 

[Roger Mummah]

The Weakest Link

Hi Bill, The reason you should not mix old with new is that the final bank with take on the characteristics of the weakest battery in the bank. So if one is older, the logic is that the older one will be weaker. I don't understand your amps numbers. Must be MCA or CCA numbers, not amps (which implys amp hours). I would not mix battery ratings in a single bank. For a house bank, the amp hour rating is what is important. For charging, all you need is a charger that has outputs for two seperate banks. See ya. Roger Mummah remummah@worldnet.att.net

 

[Alex]

2 Batteries are better .

If you decide to mix your batteries, then always use them seperately. You should not charge them both at the same time or discharge them at the same time. It will not really hurt anything dicharging them together, but you will not get all the effective volt-amps out of your battery and it may shorten the battery life.