Replacement Battery or inverter.

**Seymour Butts** · 02-03-14, 07:10 PM

I work for a 'Not for Profit' service provider to the disability industry.
We have several portable trolley type Audio amplifier systems.
Each unit has a rechargeable battery built in. The battery is labelled PM12-12 (12V 12AH) Maintenance free sealed rechargeable battery.
It would seem the batteries do not last for ever

and we are looking to replace at least one.
Each battery measures approx.:
Length 15cm x Width 10cm x Height 9.6cm (including the bayonet type terminals) The only other identifying mark is a stamp on the Top Left (opposite the RED / BLACK coloured terminals. This is stamped into the plastic and says 120718.
The audio units state the usage or draw as 60Watt RMS (I'm buggered if I know what the correct word or terminology is but I assume that's how much power is dragged when in use

)
While we are in the process of looking for replacement batteries I was wondering if we should look at keeping inverters in our vehicles for those occasions when you go to use the amplifier and the battery is suddenly as dead as a dodo. (Just like today)

Would something like work, or should I actually look at spending a little more money

Thanks for looking in

**Reschs** · 02-03-14, 08:05 PM

The date code is American and is 18/7/2012. Life is shorter than normal.
They should always be left on charge when not in use.
Without knowing the make and model, most have an external DC Input jack. No inverter needed.

A new battery is not expensive and can be changed easily.
If you are in Sydney or Newcastle I will do it for the cost of the battery.

Try your local Battery World, Altronics or Jaycar store.

**Seymour Butts** · 02-03-14, 08:16 PM

Thanks for your very kind offer but we are Melbourne based.
As far as I'm aware they are simply charged until the relevant light displays then the charge cable is removed or turned off
They are charged via a regular jug 240V cable, I don't remember seeing a 12v DC input on the unit, but I could be wrong, I'll look tomorrow and advise.
As for the inverter, would it work as a an interim work around.
We went to use one of these units today and whilst it had been on charge since Friday it lasted only 10 minutes with an ipad plugged in.
I felt that as we were in a parade if I had the opportunity to simply plug in an inverter that was plugged into the cigarette lighter, we may have had music when we needed it.

Thanks again, yours was a very generous offer.

**Seymour Butts** · 02-03-14, 08:44 PM

Just had a quick look around the net and these are the we purchased

**Reschs** · 02-03-14, 08:54 PM

You will notice the Red and Black Terminals marked External DC Input.
Make a lead from these terminals to the Cigarette Lighter socket on the vehicle for emergency situations.

Just replace the battery and make sure you keep them on charge. Plugged into the mains but switched off.
You should get 5-7 years battery life this way.

**Seymour Butts** · 02-03-14, 09:01 PM

Thank you again
I'll pick up a battery tomorrow.
Is there anything complex in the cable build??
Can I use any old existing cigarette adaptor phone charger or the like and just change the Pos / Neg attachments??

**Reschs** · 02-03-14, 10:18 PM

Originally Posted by Seymour Butts

Is there anything complex in the cable build??
Can I use any old existing cigarette adaptor phone charger or the like and just change the Pos / Neg attachments??

No electronics needed. Just buy a cigarette lighter plug, Altronics or Jaycar, and wire direct to the terminals.
I would recommend buying Banana Plugs to suit the terminals on the amplifiers.

**Seymour Butts** · 03-03-14, 07:57 AM

This thread is a prime example of why this site is so bloody good.
I didn't know, and Reschs did.
He shared, I listened, now we both know.
All sorted in just a few minutes.

Thank you

**Tiny** · 03-03-14, 01:12 PM

According to the specs of that unit it came with a 12V DC cable.

Package Contents

1 x Portable PA system
1 x Headset microphone
Packaged Under Polyfoam:
- 1 x Handheld microphone
- 1 x 240v AC cable
- 1 x 12V DC power cable
- 2 x 9V Batteries

Reschs advice is spot on.

A phone charger wont do the job, make up a direct 12DC cable if you can't locate the one that came with it.
Mine has 12v DC direct capability as well, however didn't come with a cable.

Just for some shared info.
I have a similar unit, different brand -
I use on battery & recharge mostly.
Sometimes I run it directly off a , plugged into a 12v cigarette lighter socket, which I also use to recharge it with from my solar powered battery on my caravan. Since I already had this set up I haven't bothered making up a 12v DC cable.
When on charge the amp meter in the caravan, registers approximately a 2 amp/hour at 12v draw; as this is what the inbuilt charger of the Audio system is limited to for slow charging of the SLA battery in the unit.

BTW; 60 watts RMS refers to the Audio amplifier & speaker capability, not how much power it uses.