Charging a 6v 450ah battery from flat in under 15 hours

[Green1]

Ash I need you   
I'm restoring a cherry picker for a job and I'm not allowed to use the engine so have to use battery power only.After a days use the batteries are well drained.
I can only charge it at night but the charger has gone missing so I need a new one.
I assume it needs to be fairly substantial charger as it has two 6v 225ah batteries wired in parallel  and needs to be fully charged in under 15 hours.
Any help much appreciated

Mick

[SteveD CB500K0]

Many years ago I designed military comms equipment for Racal in Bracknell.

Our 1kW transmitter was powered by 36V batteries. 6x 6V 225Ah units wired together. When not in the vehicle I charged it using a 50V 30A voltage and current limited power supply (it was the size of a 2 drawer filing cabinet).

[Green1]

Thanks for your help Steve  I hope I won't need one that big as its still 6v
So I assume your batteries were wired in series?

Just a heads up thats my electrical knowledge now spent.I will now be completely baffled buy almost everything posted from now on 

 

[AshimotoK0]

Thanks for your help Steve  I hope I won't need one that big as its still 6v
So I assume your batteries were wired in series?

Just a heads up thats my electrical knowledge now spent.I will now be completely baffled buy almost everything posted from now on 

Sorry for late reply mate . just saw this post.

I would think the charger for batteries that big would be quite a complicated affair with switch-mode regulation. Have you searched eBay for something vaguely suitable? If you did and found anything I could appraise it for you. The Americans always parallel lead acid batteries but it's not ideal unless all of the batteries are in an equal condition. Chargers are often a combination of constant voltage & constant current with voltage monitoring of the terminals.

This is a great reference on it all :-

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

[Green1]

I havn't looked for a charger yet.But I did ask the previous owner what they had in it.
It was originally run on 240v mains but the gubbins were striped out and replaced with 2 Trojan T150 batteries
https://www.tayna.co.uk/T-105-Trojan-Battery-Deep-Cycle-T105-P7253.html
and a small Hilka battery charger.
 http://www.ebay.co.uk/itm/HILKA-BATTERY-CHARGER-12-AMP-CAR-MOTORBIKE-AUTOMATIC-6-12-VOLT-CHARGER-/322085698920
I can't see that being man enough to charge it over night somehow.

If I can run a lead to it Would it be OK to run it directly through the charger if it does die?

The batteries are wired in parallel so I assume they need to be charged as a 6v battery?

One thing I did notice they have a link cable going from the negative to negative but both positives go directly to the pump without a link cable going between them.

Is it OK like that or should I run a link between the two positive terminals aswell?

[AshimotoK0]

Can you post some pics of the setup Mick . They are only in parallel if  both pos. &  both neg are linked

[Green1]

Will do I will run down the farm tommorow and take a few picks

[Green1]

It turns out I'm a muppet after wiping the crap off the top of the batteries they are actully wired in series 
So a half decent charger should be OK I guess.
what would you recommend.

[hairygit]

It turns out I'm a muppet after wiping the crap off the top of the batteries they are actully wired in series 
So a half decent charger should be OK I guess.
what would you recommend.

Like we didn't know that, you bought a moto gutless! Seriously though, as you say, any half decent charger will do it, I have an ex garage one which can chuck out 6,12 or 24 volts at anything between a constant 5 amps up to 80 amps, with a "fast charge" facility of 350amps for a max of one hour (It was bought from the coach company I worked for, £50!) but it's big and very heavy, as it's oil cooled, but it is on wheels!

[Trigger]

It turns out I'm a muppet after wiping the crap off the top of the batteries they are actully wired in series 
So a half decent charger should be OK I guess.
what would you recommend.

Which muppet are you ?

[Green1]

Fozzie bear I have been known to laught at my own jokes 

[Moorey]

If they are in series at 12v you will still have 225ah and not 450ah and ideally should charge at about 10% of capacity. So a charger that will put out 25 amp would be good.

[Green1]

Yep got in a right muddle at first because I didn't look propperly
They are 2 6v batteries wired in series so now making 12v at 225ah at the moment I am using an 8 amp charger thats not really fast enough

[Green1]

just thought I would update the 8amp charger was a waist of time so fitted a Sealy 40amp charger and now the batteries are fully charged within about 12 hours