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[TheBoy]

My charger is for bikes (or at least bike size batteries), so I was expecting better 

[TheBoy]

Its on, as we speak, I bet it won't even pull in the starter solenoid if I tried to start it.

I hate it when I'm right.

Going to stick a cheapo Clarke trickle charger on it for a few hours, then see whats what.

Incidentally, put the CTEK on the car battery I have in the garage, that hasn't been charged since late summer/early autumn, charged it for about 2 or 3 mins, then went to float 

[Marks DTM Calib]

Hi Dave

I have a ruggedised 40W panel (so in theory upto 3A of charge) and a 'regulator' (which when looking at the circuit does little more than shunt current)

[Dave DND]

Hi Dave

I have a ruggedised 40W panel (so in theory upto 3A of charge) and a 'regulator' (which when looking at the circuit does little more than shunt current)

Not the answer I was hoping you to post, but glad you did - Been looking at just that type of thing

 

[steve6367]

Solar panel with a good charger works well - use it on the boat all the time with a MPPT regulator and a normal PWM regulator in the Omega when parked up.

Steve

[Entwood]

As Steve says above ...

Solar regulators come in many forms .. cheap to expensive ..  the cheap ones are no more than "charge limiters" and will stop the battery going over 13.8v which prevents "gassing off" but does not fully charge... expect to pay around £10 ish from ebay.

PWM will do a tad more, and an MPPT even more ... but you "gets what you pay for" .. PWM chargers around £20 for a 10 amp, MPPT about double that.

reasonable write up here .. but is based on commercial setups ....

http://www.oynot.com/charge-controllers-mppt-pwm.html

I use a 60 watt panel when away in the van , and use a simple PWM charger as the panel is only connected when on site, and we are using power during that time, so the panel is continually "topping up" the battery which reduces the chances of overcharging. If I were to use the panel while the van was "laid up" so to speak I'd go for MPPT every time.

[Marks DTM Calib]

If I made the statement that the link posted has pretty much no detail and info relating to battery charging and also has errors relating to sulphation....the only way to prevent sulphation is to maintain 100% charge.

Would you be surprised...

[Entwood]

If I made the statement that the link posted has pretty much no detail and info relating to battery charging and also has errors relating to sulphation....the only way to prevent sulphation is to maintain 100% charge.

Would you be surprised...

Nope .. but it wan't intended as a treatise on battery charging .. just as an indication of the differences between types of chargers.

[Marks DTM Calib]

Sorry, didn't make myself clear.

They do nothing more than describe different methods for producing a supply from a solar panel.

1) A switch mode
2) A shunt regulator

As far as the basics of battery charging are concerned and without the sophistication of a micro to manage the charge intelligently, the only advantage no1 has over no2 is efficiency 

Furthemore they are making statements which are factualy incorrect 

[Dave DND]

So,

If I got a decent sized solar panel, for arguments sake, say a 100W one, and invested in an MPPT box to go with it

Will this keep my car or bike alive during the winter?

 

[Marks DTM Calib]

Depends on the functionality of the MPPT box because it could quite easily boil the battery to death. Having had a look at the MPPT description, it states nothing about its charge method and hence is doing little more than a shunt reg would with respect to battery charging. The only benefit is its extracting max power from the solar array.

What is needed is the likes of an MPPT box with the battery charge function of an intelligent charger (cant see any with that).

All the MPPT is doing is matching the load impedance to that of the varying impedance of the solar array to get maximum power transfer (hopefuly talking your language there Dave with you audio background  ).

So for me, no and particularly not on a small battery.

[Marks DTM Calib]

I should summarise better

The modules listed are designed to extract maximum power from the array at all times, this is thier primary purpose.

This is not the same as a battery charger designed to maintain battery charge indefinately which is more load focused. 

[Kevin Wood]

It's interesting that other people have found the CTEK 800 not to keep a battery in good condition. I commented in another thread recently that on two vehicles (my Westfield and my dad's sit-on mower), after a long period of connection they are both reluctant to start but eventually revive with a bit of regular use, a jump start / more aggressive charge. I wonder if this needs investigating?

FWIW, I don't think the XS800 is a very "smart" charger. It has two phases as far as I can see from casual observation:

1) Charge battery with current limit until a set voltage is reached.
2) Sit idle until a lower voltage is reached

So, no obvious absorption or float phases.

I'm actually wondering it it doesn't maintain a high enough level of charge to prevent sulphation.

[Kevin Wood]

I also notice that the current XS800 has a couple of extra LEDs on than my example.

[TheBoy]

The destructions for xs800 state its 3 phases are charge, absorb, maintenence.