paul replied:

last question my answer is "nothing". I do it with my 12amp solsum 3 stage charger in front of a 12 amp auto charger running of mains (note it does not put out 12 amps only sucks in 12 amps off 240v so probably puts out about 6amps at 12v) on my 55a/h battery and use a $20 dick smith single stage charge with float charge from a $25 Arlec 4amp (not what comes out0 charger) off mains charger - but i don't leave them on - why waste electricity - i just charge them once a month if not used and straight after i use them cause i can leave them overnight and not worry about any overcharging.

dunno bout you're other questions

firey replied:

Hi Rod, Am currently going through this dilemma myself with trying to fit a battery charger to a camper trailer so it runs of a genie when outback or mains in cara parks etc. try this web site for info on three stage chargers www.baintech.com.au or type in battery chargers for a search in au only.Baintech are in Cleveland and supply battery chargers to Camec Australia etc. And from looking at there price list your dreaming as the cheapest three stage appears to be around $600.
Regards Firey

paul replied:

Rod

One more thing - Transformers usually put out about 12.00 volts or thereabouts because their main purpose is to run an appliance. However, to recharge a battery you need ideally about 13.4 volts or higher but not higher than say 15.00 volts. So if your transformer only puts out a standard 12.0 volts you are not going to get anything charger, better check that out with a multimeter and mayber get a purpose built battery charger and slot your Steca in between.

By the way - did you ever get the instruction booklet translated into English ? If so, can you put up a summary of the combinations of flashing lights (but i bet you did the intelligent thing and got the LED readout model).

Good luck.

Rod replied:

Paul

Thanks. I am aware of the need to have > 12v out of the transformer and was aiming to use 15V as my BP Solar cells put out a nominal 16V to the Stecca. DSE sell such a transformer.

I'm now worried that 5A may be useless if trying to charge the battery up from a state of say 20% capacity. I've seen figures that indicate the charger should be rated at 10-30% of the AH rating of the battery. For my 105AH Trojan, this means > 10A. Given I've got the 6A Stecca, I don't want to go above 5A input to it. Maybe I should have bought a bigger stecca ?

My Stecca has the two LEDs and whilst the top multicoloured one is easy to interpret I must admit that the bottom one is sometimes steady, and sometimes flashes at different intervals. Do you have a similar model and have you worked out the bottom LED ?

Thanks

paul replied:

Nope to the bottom light - but someone where i work has just started and i heard she speaks and reads fluent french so i'll be pulling the manual out this weekend.

The 10% rule is the maximum, not the "recommended" as anything higher for a wet lead acid battery can cause the acid to bubble which may cause the plates to warp which will wreck them - my understanding is that so long as the voltage is correct, the lower the current charging rate the better as it allows deeper and steadier penetration of the plates. So i honestly believe you will be fine if you have the voltage correct, just might take longer to charge the battery than if being charged at 10% but if it is just sitting at home then there is no problem.

Member - Nigel replied:

I use a LEAB Champ 8 amp charger (coz I couldn't afford the 17 amp model).

It's a mains switch mode 3 stage program charger, that works from 170-260 volts, 40-60 amps (ie will cope with generator or other poor power supplies). It's epoxy filled and fully waterproof so will cope with offroading (we use it to charge the trailer and topup the aux in the vehicle).

The price was well over $100 - more like $400. But well worth it for me as I have 3 deep cycle batteries that will probably last more than twice as long due to proper charging.

Some solar regulators don't like any capacitance in the power supply but a straight transformer/rectifier without filtering should work fine.