if he'd get three independent chargers then this is not a problem.I hooked up my three Soneil chargers last night after riding around and doing some trimming work in the evening. The two 12V 100ah batteries I have were at about 70% and (each attached to one charger) are full this morning floating at 13.8V. The two larger 6V are hooked up to my third 12V charger. These batteries were at about 80% andthe 12V charger was still working on them this morning (13.6V) butshould be done soon.
Oh sure. I have a similar problem to this on a much larger scale with my electric car (50 12 volt batteries in two strings of 25). I've thought about just giving up on balancing and buying 50 chargers :-) Only problem is if a charger fails and I don't know about it I will wreck the pack.
The only issue I see with three 12V charge controllers is that the power diverted by one charge controller when the battery reachesfull may not be available for charging the other batteries. (I think you made that point in an earlier mail)
Yes. Solar energy is expensive. You also have to think about imbalance issue since different panels will get different levels of sun over the day.
And no matter what you do, don't think one can put the 12 volt panels in parallel for 12 volts, feed that to a common bus for 3 charge controllers and then put the controllers on the batteries. You will wind up with at least two blown controllers as they will short themselves out (not isolated)
Another option is to get a battery balancer thaat can take power from the 24 volts of not-used batteries and feed it into the 12 volt battery string when needed. This could actually work, and solar shops are known to sell these sorts of things. They can't keep up with the peak drains on the 12 volt battery but over time they equalize by charging the 12 volt off the backs of the 24 volt.
Chris