Dan Brocington

FOlks,

thanks again for this helpful advice; I will source a voltage converter soon.

with best wishes

Dan

Peter, thanks again, we will look for a new one. I'm hoping given that the older battery is only 3 months old that things will not be too bad. Do you know if there is a window of acceptable age difference for old and new batteries.

Also do you know the answer to the question I posed at the end of my previous post?

Dan

Folks,

Thanks all for these suggestions and comments. It was Peter's suggestion that nailed it. The 6 panels had been connected in parallel. I reconnected them in series (3 lots of 2) as suggested, and now the batteries are charging. @Peter - thanks much!

We may still have problems with the controller - and we may also have batteries of unequal strength (@Jeffrey thanks for that tip). One is new and one not - but both were fully charged at the local charging station before installation. We will keep an eye on them. At the moment I'm just enjoying being able to work the fridge, computer and water pump without the batteries dying.

One more question if I may: Our bulbs are 12v dc and several of them, of course, melted when the 24v system was connected. (I do hope you find this as amusing as my family did). We have now wired the bulbs to *one* of the batteries which is connected in series. Will this yield a 12v supply, or will there still be 24 v coming off the one battery.

thanks again,

Dan

Apologies, please ignore my last while I double check the wiring, I may have got that wrong.

Thanks Peter, you are quicker at drawing than I am, that looks like what we will attempt. I've just been up on the roof to check how things are wired. We currently have 2 sets of 3 panels. So 3 panels in series. And then the two sets of three meeting in the charge controller. Each panel is 100 watts. We originally had 4 panels (in two sets of two) which sufficed for the 12v system. So I'm guessing that in not going 3*2 that was our mistake. Does this sound reasonable?

Peter, thanks so much for a super quick reply that could indeed solve the problem. We have 6 panels. So I'm guessing we need to put them in three pairs - each pair in series and then the three pairs in parallel. Please could you confirm / corrent?
Would you mind if I sent you a diagram of what we end up doing? thanks again.

I live in a remote part of Tanzania with no mains electricity. We have had solar power for some time, but on purchasing a new inverter, battery and extra solar panels have run into problems. The problem can be simply stated. We have two N200 lead acid batteries both yielding 12-13V each. Connected in series we get 25v from the system.

The inverter (Shiv Solar Comercial UPS 2000-24V) requires that the batteries be connected in series. If they are connected in parallel the inverter quickly triggers a ‘low battery warning’.

But the batteries will not charge when connected in series. Each will charge on its own. So there does not appear to be a problem with any of the connections. Moreover both will charge together when connected in parallel. Nor does it make any difference which way around we connect the batteries in series.

When I say that they do not charge I mean that the charging sign on the controller indicates that the batteries are not charging. Also the Amp level reads ‘0’ for both the solar panels and the batteries. The volts show a positive reading (batteries on 25, solar panels vary according to the sunlight).

We know that single batteries charge on their own because the charging sign on the charge controller indicates that they are and the ampage is positive both for the panels and the battery (varying according to the sunlight).

What would cause this problem?

The only thing I can think of may be that the solar charge controller (ViewStar series 4048) has limits set in it, that prevent charging when the batteries are connected in series. But its internal limits seem to be fine for the batteries needed. When we connect them in parallel it detects a 12V system and sets parameters accordingly. When we connect them in series it detects a 24V system and doubles the parameters