charging 10 deep cycle batteries with 1 charger

here is what i have
10 12volt deep cycle batteries. several different kinds with various ages.

a 2 amp trickle charger.

here is what i need to accomplish.
these batteries are used seasonally and now i would like to put them away for the winter but some are full and some are part charged.
i do not have the ability to charge each one fully and then switch the charger as they are located in a remote area.
i know i can connect them in parallel to charge but to do so i would need to have a diode connecting to each + battery terminal.

i do realize there is voltage drop and i am ok with that as long as come the next 2-6 months my batteries will be ready to go (fully charged).

here is the problem. i do not know what type of diode i need and if this is a simple set up or something more complex than the convenience it is to provide me.

i have searched the internet for ideas like this but all i come across is expensive battery isolator (to hook up to an alternator to charge 2 batteries) which is not what i am looking for.

any info appreciated.

you are not given full description like battery ah, ampere & volt of charger etc

In it's simplest form, if the trickle charger is set to produce 2A, any diodes rated at more than 2A will work. I doubt the ~0.7V drop per diode will cause any problems. I would have concerns about the charge being shared equally between batteries though. It is true that if each battery is identical, and reaches full voltage, the residual trickle current will be shared but in real life I think you might find one battery hogs all the current and leaves the rest only partly charged. The only foolproof solution is a charge regulator per battery but to do that you obviously need more circuitry and a higher voltage to start from.

If the batteries are stored close to each other, it may be possible to rotate a single charger from one to the next, possibly using relays and a timer, so over time they all have their own time on the charger. Although it isn't "high tech" it may be the optimal solution and given the remote location it gives you confidence that if one battery dies, the remainder will still be charged. Using the diode method, if one battery draws too much current it would leave all the others uncharged.

Brian.

Thanks Betwixt.
i want to avoid rotating batteries as i used to have to make special trips to the remote location (well remote as in 30 mile away and did not want to do extra trips).
here is another question. i understand your real life situation you note, but if one battery hogs all the current will it continue to hog all the current even when it is fully charged or does the current always go to the least charged battery. if such is the case i would expect it to go from one to the next battery until all batteries are fully charged. OR, can the battery which hogs the current continue to hog the current even once it is fully charged.

Paradeep
the batteries are 115 amp hours
the charger is a 12v charger with a 2 amp output.

for 115ah 12v battery 2amp charger is not capable to handle the full charge and you said batterys are located 30miles away then how you can conect each battery to the charger.

The relatively low rating of the charger would not cope well with current sharing. You are right in assuming that the charge current will drop as each battery terminal voltage reaches the charger voltage but that also assumes that all batteries will reach the same voltage and their trickle currents are equal when they are fully charged. In reality, even small differences in voltage and current through individual batteries will cause a large change in the balance between them, especially considering the charger will barely produce enough current to trickle charge them all anyway. Remember that to provide trickle charge, the voltage applied to each battery must be slightly higher than it's terminal voltage.

I wasn't suggesting you physically 'rotate' the batteries. What I meant was you can connect all the negative terminals together and back to the charger then electronically connect a wire from the charger to each positive terminal in sequence. So the charger is connected across battery 1 for say 5 minutes, then disconnected and reconnected to battery 2 and so on. This ensures each battery gets charged and also gives a 'cooling off' period between charge periods. If each battery is completely isolated from the others, you can connect the negative side sequentially as well. The circuitry to do this is very simple.

Brian.