Silly question on battery chargers/conditioners

gorrie · Post by **gorrie** » Fri Dec 21, 2007 12:15 pm

I know that you can buy a battery conditioner from Lotus (trickle charger & solar trickle charger), and I 'believe' that they're designed for you to connect while the vehicle is laid up in winter (or maybe while on holiday). I was also under the impression that you could use these without removing the battery or disconecting the leads (ie, so the electrical circuits in the car are still intact)... but I'm happy to be corrected if that is bull...

My old man always told me to disconnect the leads in my cars when performing a charge (whether full or trickle)... in case it knackered the cars electrical gubbins

Now, my charger (that I've had for quite a while) is a Gunson G4106 and it's got a switch for a full charge/perm-float and it's got a switch for Automatic On/Off. Does this mean that my charger is suitable to connect to the battery while it's still connected to the cars circuit (while on auto/float?) if it's laid up in the garage for a while .. which means I can still have the immobiliser engaged? It goes against what I've always done..

I've totally removed the battery for a full charge from dead anyway, but would be interested for future ref.

Andy.

fd · Post by fd » Fri Dec 21, 2007 1:12 pm

Small trickle chargers probably don't have the balls to damage anything - I use one on my car every time it's parked up in the garage out of habit . . . no issues . . .

A larger charger, however, may cause you issues if your battery is gubbed . . . most simply output a full wave rectified sine wave and use the battery as the damper to smoother that out . . . but if the battery is gubbed (say a dead cell and open circuit or very high internal resistance) then the battery will not smooth the charger output and you may get the rectifier output from the charger into the car electrical system (which will probably be IRTO 22V ripple peak).

I'd be surprised if this actually damaged anything as car electrical systems are quite hostile places and most car gear is well protected . . . but who knows . . .

If your charger has a float setting . . . I'd have thought it would be ok . . . but best check the manual if you have one . . .

Fd

gorrie · Post by **gorrie** » Fri Dec 21, 2007 2:01 pm

Cheers Fergus... had the charger for years, so needless to say the box/instructions are long gone.

But, I did manage to find a pdf for my model on the Gunson website and it seems to suggest that I can attach this to the battery while it is still connected as long as any drain (alarm/immobiliser) is not greater than a certain amount (otherwise there is a thermal cut-out that may be breached). It goes on to say that the Auto/Full setting outputs 14.5V (which it says is similar to an alternator) & that the Auto/Float is 13.9V to try and eradicate gassing.

Should be OK to to this on auto/float although it uses typical trickle charge rather than pulse charge, so would probably want to keep an eye on it the 1st couple of times I try.

BiggestNizzy · Post by **BiggestNizzy** » Fri Dec 21, 2007 2:02 pm

If you connect a full bunna charger to the battery and it's still connected if goes ape sh1t doesn't like it one bit

hiscot · Post by **hiscot** » Fri Dec 21, 2007 2:44 pm

the 340r had an option for trickle charging ( std battery required body removing to remove battery )
http://www.340r.net/plug.htm
it was also recomended for anyone using a red top race battery
i use a motorcycle battery conditioner fron aldi only cost £5 and moniters the battery state then switches on/off as required hence not overcharging of course its a very weak trickle charge so only tops up what the alarm takes out, in effect
being a early s1 i have a live cigar lighter so i have swoped the croc clips and fitted a cigar adaptor instead, hence i dont need to lift the bonnet
the later elises had a ingnition on only, cigar lighter

Pedro · Post by **Pedro** » Fri Dec 21, 2007 4:26 pm

Hey Guys,

Sorry to hi-jack this thread...But I really wish I could use one of these battery conditioners, but my garage has no electricity.

I am thinking about putting a solar panel on the roof of the garage, and connect this to the car when garaged, but I am worried the solar panel trickle chargers will overcharge...not sure they have the auto switch off/on like the conditioners do..?

Cheers,
Pete