Charging 2 batteries at the same time

[whopperstopper]

I just checked the charge on the batteries on my boat. I switched my selector to 1 and the voltage to my Depth finder and my GPS read 12.3V. Switching to battery 2, the voltage was 11.7V <br /><br />Of course, the one that reads 11.7 is the hardest to get to. Both batteries are new, less than 2 months old. <br /><br />Can I switch my battery selector switch to BOTH and charge them or do I have to go ahead and disconnect and charge the one with the low voltage? With the switch on BOTH can I just clamp the charger on to the battery easiest to get to?<br /><br />I did a search, read a bunch and did not see this question.<br /><br />If you have an answer, keep it simple. (please)

 

[LubeDude]

Re: Charging 2 batteries at the same time

Providing the two batteries are of the same manufacture and size, (They should be), You can charge them together with the switch set to both. It will work by just hooking to one of the batteries, but it will equalise them better if you put the negative on one and the positive on the other if posible. Why, I do not know, but its true.

 

[ThomWV]

Re: Charging 2 batteries at the same time

Capt. Ken,<br /><br />Lubedude steers you right. Put your charger on the battery you can reach and it will take care of them both (with the selector switch put in the "Both" position) but given the choice put one clamp on the positive terminal of one battery and the negative on the other. However, let me caution this one thing. Just charge them enough to bring them back up this way, do not stick on a charger this way and then just walk away for a day or two.<br /><br />I am not going to elaborate on this much here, but I'll mention it. If you try to bring both of those batterys up to full charge doing it this way the result is inevidable, you will not be doing yourself or your batterys any favor and in fact to some small degree will harm them. I'm going to mention this a lot more when I go back and continue the discussion in the following post:<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=27;t=001351 <br /><br />Thom