Charging one battery with another thru and inverter

if its only getting used occasionally would one of those bleep poor el chepo solar panels for recharging from supercrap do the job? at least you wouldnt cry if it was flogged

Would be better to use Arrid charger - it is more effective then inventer + charger. But if you do not care about discharge "donor" battery a bit more inventor will do.

I believe if you hook 2 batteries together one flat the other full that they would level each other.........or a bigger one charging a smaller one.........am I wrong.

Reiner

Porl
Why not just swap the batteries over. Eric

An inverter driving a multi-stage battery charger is one way to do the job. However if you value your battery and want to use quality equipment you will find a RanOx Battery booster a cheaper and more efficient way to do the job.

PeterD

There are other 12V powered battery chargers that are used by the Electric model plane/helicopter/model car people and are very flashy, relatively cheap and will probably do the job you require.

I have one thats about 8 years old, called a SuperNova 250S. I use it to charge all manner of NiMh rechargables, but it also charges Lead acid up to 50Ah capacity.

I've just been playing with it in the shed. I've powered it from a small 7Ah gel cell, and used it to recharge my twin N70 batteries (160Ah) to see what would happen, and whether it would work.

Well it worked very well - even though my car batteries were already well charged, it still upsized the voltage to 14.12V and was putting 4.2 amps into my car batteries. The voltage on the small gel cell was 12.37V while the charger was going.

I don't think the SuperNova are still around, but they have been replaced by fancier models. An example is the Swallow battery charger from Model Flight. For $99, its a bargain, but you can spend a heap more money for the flashy German built chargers listed on that site.

This has the ability to charge almost any type of battery (NiCAD, NiMH, Lithium and SLA), but as far as sealed lead acid batteries go, it will also charge them at up to 5 amps. Input voltage is 11-15V.

I will add a disclaimer that I haven't used a Swallow Charger but its specs are the same as my SuperNova, so I can't see why it wouldn't work.

Cheers
Phil

Just connect the two batteries together, don't fuss with an inverter or anything. The load from the batteries will be supplied ok from both batteries and there are no losses, with a charger run off an inverter I would expect in the order of 50% losses.

No Problem Porl from the electronics point of view.

Thats what I do with my $39 laptop supply invertor with the output set on 15v and a small resistor is series to limit peak current.

I use an 18ah gel cell to run the laptop converter and its fairly portable and is great to top up bigger batteries.

Saves me some time as I have a tractor left unattended for weeks some times, and the boost gets her started without having to remove the main battery.

If you were to leave such a device connected and unmonitored for hours then you need to add a series power diode to drop charge volts to 14.4