I have a display prop that needs to be powered through DC plug, i can’t connect it to power so i need a solution that works with batteries or any other way that doesn’t include a power outlet.
The prop voltage standard is DC12V, current 3A; power 36W and above if the voltage exceeds 12v -such as 24v or 36v - the prop will be damaged.
Can you please provide an option that works for this prop? I was looking at your product SKU: ADA875 but i was told this product would not work because the current 3A of the prop would drain the batteries very quickly.
More info please. How long (hours) do you expect this battery to power your prop before recharge. This will determine the battery capacity you need. Without this “12VDC” means nothing.
The prop needs to be on 8 hours a day. Cheers
That equates to 24Ahr. You need to take into account the degradation in capacity at higher loads. The rating of a battery in Ahr is normally quoted at the C (capacity) / 20 discharge rate which rapidly degrades at higher rates. I have attached a graph illustrating this for common lead acid batteries. A similar thing occurs for all chemistries.
You can see that a 30Ahr battery discharged at 3A (C/10) will get down to 10.8V in 6 hr, not the 10 hr expected.
I might mention here that 10.8V is the lowest you should discharge a lead acid battery without the risk of damage. Some like myself prefer to work at 11V.
On this basis I would suggest for your application at minimum 60Ahr or I think a stock size is 75Ahr.
DO NOT use an automotive battery, It will die fairly quickly with your use.
DO use a deep cycle battery. They are built for this sort of application. Preferably Gel or AGM types. It will have to be charged every day or it may be that after practical trials and a large enough battery you might get 2 days. Get a suitable intelligent charger.
You can use other chemistries but be aware they will all have different charging requirements. Do not even consider just hooking up a power supply. You could have an expensive disaster on your hands.
PS Jaycar have some deep cycle batteries that have their rating quoted at C/10 but these jump from 38Ahr to 75Ahr ( in my 2020 catalog ). An up to date one might be a bit different.
thank you very much for all this info Bob, extremely helpful
Hi Hose, Welcome to the forum!
Bob is on the money here, I was going to suggest a lead acid battery if you need 12V and don’t care about the weight. They are definitely a lot safer than a multi-cell LiPo that you’d need in order to get 12V in a lighter package.
Another option if cost is no object would be a small LiFePo4 battery bank. These almost always have a 12V output capable of high current: Portable Power Stations for Sale - BLUETTI AU
One thing to consider is that Lead Acid batteries can get as high as 14V straight off a charger.
EDIT: I’ve just ben informed by our product team that we now carry Lithium Phosphate cells! These are somewhere in the middle of Lead Acid and LiPo for safety and power density, worth a look!: