battery hookup

I have 2-12 volt batteries connected +to+ and -to-.My question is, when charging with a portable 10 amp charger, would it be better to connect the charger to the positive on one batt and the neg on the other batt.Also would it be better to connect my trolling motor clips the same way, or would there be any difference in connecting the charger or trolling motor +to+ and -to- on the same battery when using 2 batteries connected in parallel ? Will it make any difference in the charging or the draw down of the amps when using the trolling motor?

It will not make a difference either charging or discharging which battery you’re hooked up to, since both terminals are connected by a very large, low resistance connection (the large battery cable would probably measure milli-ohms at most).

Gianni, Is there any danger to the charger from the two batteries possibly drawing too many amps?

Shouldn’t be. Think about it this way: The same charger is designed to handle all batteries, from totally dead to fully charged. When you hook two batteries up in parallel, it’s like having one battery with twice the capacity.

Now that I’ve said that, a disclaimer:

Gianni does not work for any manufacturer of on-board charging equipment, especially whichever one you own, no matter who you are. He dispenses advice well worth the cost paid in a spirit of goodwill and good intention, but is not always right. He assumes no liability incurred due to acceptance of or action taken as a result of acceptance of his advice. Gianni’s advice is known to the state of New Jersey to cause testicular disese in laboratory animals. Small children and flammable items should be kept from Gianni’s advice at all times. We are all spinning unavoidably toward the black void of death; acceptance of Gianni’s advice (especially in matters realting to electrical and or navigation equipment) is not intended for use in halting this phenomena.

Quote:

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Gianni’s advice We are all spinning unavoidably toward the black void of death; acceptance of Gianni’s advice (especially in matters realting to electrical and or navigation equipment) is not intended for use in halting this phenomena.

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Or accelerating it!

I would like to use the disclamer above also…

If it’s a 10 amp charger, all it can put out is around 10 amps. I would just take longer to charge two batteries.

I have been running two 12 volts in parallel for a number of years. I use a automatic 10 amp charger and charge them as much as required. I have also heard about the need to have same year/age batteries in use. This I have never done….I currently have a 1998 and a 2002 in front for the electric trolling motor’s……The 1998 is probably in it’s last year of use. Four years is good from my experiences!

That is a great disclaimer! : bow:
It almost brought tears to my eyes.

G-Man, you’ve been sniffing battery acid again, haven’t you???