Solar battery charger questions.

[tambox]

If you connect 2 of them in series, you will need a 24v charger and the batteries have to be identical type and condition. For this setup to evenly charge the batteries and not degrade them with unbalanced charging, you will need a charger that monitors the centre connection @12v. Complicated and expensive, not recommended.

In parallel, (both terminals commoned) if you use a fully electronic automatic charger, that cycles the battery, charges and then trickles, no.
If you use the arlec 4/6 with Jaycar setup, yes.
If you use an limited control standard charger, yes, but its not good for the batteries.

If you are going to series/parallel the batteries, it is better if the batteries are the same. If they are different, to save headaches, its better to have independant chargers for each battery.
Independant chargers are better anyway.

I have a fleet of independant electric/solar chargers for single batteries, the only ones that are in parallel are the wind generator/solar bank. The wind/solar are all different sized batteries, not the best way to do it, but they were available at the time. Due to these being the wrong type and not matched, they have a short life, working on improving this when I can justify $$.

[pitrack_1]

As tambox said. You're better off with one good charger than several dud ones. Cheap overseas internet imitation ones often have a good looking case and bad, bad innards.

Suggest (to begin with):
1) A good electronic mains one for home. You can swap between batteries as you like, electronics take care of everything.

2) A solar panel + regulator (such as Jaycar ones listed earlier) for trip maintenance. Experiment with moderately priced ones then you can buy a more expensive, suited setup later AND keep the cheap one as a battery maintainer.

Set up your connectors/plugs adroitly and you can power the Jaycar battery charger/maintainer off the cigarette lighter plug whilst driving (Note: VENTILATE BATTERY WELL). Don't connect the battery directly as a discharged/shorted battery will blow the fuse by drawing too much current (alternator may not like it either).

3* (* for bonus points ) A good RC/hobby battery charger. Not only can it do your RC stuff but it can do Pb-acid batteries too. The IMAX B6 Quattro Charger looks good- it may do multiple Pb acid batteries (and your hobby batteries). Can power it from the car and it will auto-shut off to protect the car battery. Not sure the control will be as good as a dedicated Ctek type, but can generally/sometimes be programmed similarly if you know what you're doing. Beware cheap online imitations esp. for RC batteries- improper charging (fires, explosions, etc, look on Youtube for Lipo fires/explosions). Note I haven't used RC batteries.

[El_Freddo]

I have the Jaycar CAT. NO. MB3604 5-stage

I'll have to check this unit out. Seems to be what I'm after for the gap at home between vehicle use/charge periods.

Cheers

Bennie

[tambox]

If you are going to let your batteries discharge, before connecting the charger, these are good.
BUT, if you connect this Jaycar CAT. NO. KA1795, with a $20 charger, soon after you park the car, this will work well. And its cheaper.
You only really need the cycle chargers if you have let the battery loose charge.
If you connect to a trickle charger, with enough capacity, soon ( this depends on how much current your accessories draw from the battery) after you finish driving the car and the battery has not been "flattened to much", the CAT. NO. KA1795 with an Alec 4/6 will work well.

If you are going to let the battery discharge, before connecting the charger, then use an electronic cycle charger like you describe.

[El_Freddo]

So there's really no all rounder for either full recharge after being drained and maintenance charging/cycling?

I guess I'll steal one of the little chargers Dad has for flat batteries and get a set up sorted for cycling/maintaining the battery...

Have I got this right (finally)??

Cheers

Bennie

[tambox]

The electronic cycle battery chargers are the best if you are going to let the battery discharge.

One of the keys to good battery life is the trickle charger voltage level, most battery chargers do not control this very well, the Jaycar CAT. NO. KA1795 overcomes this problem.
If you are "I guess I'll steal one of the little chargers Dad has for flat batteries and get a set up sorted for cycling/maintaining the battery...", add the Jaycar kit.

If you are not going to leave the batteries on constant "controlled (jaycar or similar)" charge and you are going to let them discharge, then go electronic.

If you are going to have a constant current draw on the batteries (alarm, radio,clock etc), you need to leave them on controlled charge all the time.

If you are going to use yours dads chargers with no control on them, they will cook the batteries. Even on a timer, they are not good as the float voltage is not controlled.

Bottom line is for good battery life you need to charge at greater rate than the rate that acessories draw, do not let the battery discharge and do not overcharge. Float it at a controlled voltage, ideally in good temperature and it will be happy.

[pitrack_1]

So there's really no all rounder for either full recharge after being drained and maintenance charging/cycling?

Yes there are, but you need to pay. Jaycar CAT. NO. MB3604 5-stage, CTeks or better should do the job, that's why they have multiple stages. The better ones have "recovery" modes for deeply discharged/damaged batteries too.

I guess I'll steal one of the little chargers Dad has for flat batteries and get a set up sorted for cycling/maintaining the battery...

What tambox says.

Have I got this right (finally)??

Almost. Reading between your lines, it sounds like you have both batteries to be maintained and batteries being dis/re-charged.

Perhaps some clarifications:
- A Battery Charger will recharge a discharged battery. If left on an unregulated one will eventually damage a charged battery.
- A Battery Maintainer will keep a charged battery charged without damaging it. It should slowly recharge a drained battery. It probably won't recover a fully dead battery (like a 12V battery taken below 10V). Also more-or-less known as a "float charger" or "trickle charger" as it keeps a constant (float) voltage on the battery at a low (trickle) current to maintain the battery.

a) Get deep-cycle batteries for your dis/re-charging uses (eg for camping). Normal batteries will suffer reduced lifespan and capacity from the first deep dis/re-charge.

b) A good electronically controlled/regulated battery charger will function as a battery maintainer too (that's one of its modes).

c) Something like the Jaycar MB3604 will suffice to start, covering both charging and maintaining (but only one battery). If you have bigger than a 'normal' car battery to recharge- eg diesel, V8 or larger- seriously consider a larger capacity charger than the Jaycar MB3604.

d) But sounds like you'll also need battery maintainer(s) for the charged batteries (eg in seldom used vehicles). Note you need to supply the basic charger, solder together the KA1975 kit and fit/house it too.

e) One last thing to get is a surge protected powerboard, double plug or in-line socket for the electronic chargers. Especially if they're connected to the same circuit as the old fridge in the garage/shed!

Cheers

Patrick.

[El_Freddo]

Thanks Patrick.

I already understand that a battery cannot be left on charge long term with the type of charger that recharges a discharged battery.

If the battery was discharged I'd be using one of the above chargers before putting it on to the maintainer system thing that I was looking at getting above.

My vehicles usually get driven regularly, but in this case RS was set aside to look after a mate's car. I really only need to maintain the 2nd battery as I don't want it in the car all the time, but I do want it to work when I need it.

Thanks for the tip about the surge protection!

Cheers

Bennie

[pitrack_1]

Mucking around online, I found the Matson SCM54E looks good.
- 4 separate channels (batteries)
- 5-stage charging (per channel I assume)
- 5Amps / channel
- desulphation mode

Not cheap, cost I found online is ~$315 but that gives ~$80/channel. They're also a local Aussie family-type company based in Sydney you can probably phone and ask questions to- or get advice directly from- the engineer(s). I've found this is often worth more than the cost of what you've purchased in the first place. One other company like that, incidentally, was Top Gun (the spark plug lead manufacturers).

One other thing (again!): Be careful of extending the cables on electronic chargers. The extra wire impedance/voltage drop can interfere with the electronics and lead to incorrect charging.

Pity I don't have 4 batteries to charge/maintain!

Patrick.

[steptoe]

Model PMW20PW
Max sys 1000V
Voltage ( VWP18.0) 12V
Current (L) 1.12A

is what's on the label on the back of a solar panel I have had kicking about - pointed at the sun produced 20.9V

thinking could be put to use to keep batteries charged up ither in car or out but that 20.9 V is a bit of a worry - so a regulator is needed yep ?

What can I do other than spend money to reduce to a suitable charge Voltage for a 12V lead acid battery car size ?

Can I pinch a regulator out of an old alternator?

Is there something else to add to the equation to stop the battery being over charged once 'full' ?

or have i not learned something from above posts
Initially bought panel to charge a pack of 12V SLA's for a wireless security camera , bought a pair of padlocks meanwhile and now the suspected trespassers/vandals have moved up in the real estate , remote camera idea never got off the ground

[tambox]

What you are measuring is the open circuit voltage of the panel. Which dose'nt mean much, as it is the maximum voltage the panel will put out, when there is no "load" or current draw.

If you were to put a 12v light globe across the panel, in sunshine like when you measured the voltage, the voltage would have dropped by a lot, as now you have a "load".

From the specifications you gave, the panel will supply 1.12A of charging current, when the panel output voltage is at 12v, (in bright sunshine, faced directly at the sun).

If you connected this across a battery, faced it into the sun, it would charge the battery,BUT, as you have no regulator, it could eventually over charge.

Now it gets complicated, it all depends upon how many hours of sunshine your panel gets, how flat the batterie/s are, how much current they need to charge, how much they self dischage over night, diodes?......................

Many variables, two easy options, keep an eye on the battery voltage, once it reaches its "recommended" voltage, disconnect the panel, or buy a charge regulator of fleabay.
Car regulators, generally, control a field current, which is tricky on a solar panel, it would be the same as turning the sun down.

[steptoe]

aha, there is a diode in the connector box I ripped off in disgust of getting a second panel with sh1tty connectors, near threw it out, then took another look.....got it from a crowd in Sydney as replacement for one half its size that had a fault slipped my mind, they ignored phone calls, emails until I mentioned fair trading

I'll repair things and include the diode, hook up a battry and turn on the sun and see.....

[Brumby Kid]

It's gonna rain now steptoe........

[GerardWilliams]

solar panels are good, in the right enviroment.
I have played with some solar setups, mainly trickle chargers for vehicle batteries.
Be aware of the different types mono, poly or amporphous as it varies their life/performance.
In summer a small solar panel, ie $19.99, will keep the battery good, provided you have nothing else drawing current, ie alarm etc. (siuts my brumby)
In winter, due to lack of sunlight and cold weather you need at least a 2 amp panel.
I eventually deicided it was easier and more beneficial to run a 240v "fully regulated charger" on the bigger batteries with other accessories drawing current. These are great, they cycle the battery (to increase battery life), then charge, then trickle once the battery has fully charged.
The cheapest way to do a good controlled charge system, is to buy the good old Arlec4/6 from kmart for about $25, then a kit from Jaycar for $19.95.
I have been using these for years on cars, tractors and trucks.
Batteries last much longer and work when the key is turned.
Saves getting out the "chainsaw alternator" for a quick charge.

These work for me.

These panels are best.. We are able to save money as well can contribute to nature saving cause by installing solar panels on roof..