Gel battery on boombox?

[reezlee]

hello everybody,

I recently bought a Philips D8778 for only €25 at a second-hand store in top-condition. I'm really happy with it but I would like to take it to places like camping and such. Ofcourse I could always buy 10 pair D-sized batteries but I'm looking for an alternative. I still got a 12v gel batterie from an old security alarm laying around here. So I'm asking you guys if you got any experience with doing this are mayby some other ideas.

Thanks in advance

 

[redbenjoe]

welcome --

and you have the best idea already -- those 12 v gel cels LAST !!
and you can recharge them a few hundred times

is yours about a 7AH rating --?
they are not to heavy and have plenty of loud hours --

plus --buy a back-up 7AH -- and you can play forever

 

[Lasonic TRC-920]

Radio's typically have a 12v in plug, if you find an old power supply with the right size plug for the radio, cut it off, attach it to the battery and plug it in. It should work

 

[reezlee]

Thanks for the fast responds folks!
I just had a look at the battery but I noticed that it's 2.1 Amp. Hr. so I don't think it's gonna work.
I also have to inform you guys that I'm a real "noob" when it comes to electronics. "sadly enough".
So the best thing to do is to just buy a 7AH right?

 

[BoomboxLover48]

2.1 amp-hour should work for the use but usage time before recharging will be less when compared to a higher amp-hour battery like 7.0 amp-hour.

The amp-hour is a unit of battery energy capacity, equal to the amount of continuous current multiplied by the discharge time, that a battery can supply before exhausting its internal store of chemical energy.

Amp-hour is a unit of measurement for battery capacity, obtained by multiplying a current flow in amperes by the time in hours of discharge.
Example: A battery which delivers 5 amperes for 20 hours delivers 5 amperes times 20 hours, or 100 ampere-hours.

A battery with a capacity of 1 amp-hour should be able to continuously supply a current of 1 amp to a load for exactly 1 hour, or 2 amps for 1/2 hour, or 1/3 amp for 3 hours, etc., before becoming completely discharged. In an ideal battery, this relationship between continuous current and discharge time is stable and absolute, but real batteries don't behave exactly as this simple linear formula would indicate. Therefore, when amp-hour capacity is given for a battery, it is specified at either a given current, given time, or assumed to be rated for a time period of 8 hours (if no limiting factor is given).

For example, an average automotive battery might have a capacity of about 70 amp-hours, specified at a current of 3.5 amps. This means that the amount of time this battery could continuously supply a current of 3.5 amps to a load would be 20 hours (70 amp-hours / 3.5 amps). But let's suppose that a lower-resistance load were connected to that battery, drawing 70 amps continuously. Our amp-hour equation tells us that the battery should hold out for exactly 1 hour (70 amp-hours / 70 amps), but this might not be true in real life. With higher currents, the battery will dissipate more heat across its internal resistance, which has the effect of altering the chemical reactions taking place within. Chances are, the battery would fully discharge some time before the calculated time of 1 hour under this greater load.

 

[reezlee]

Great! I totally get it!
Thanks for all information you guys, I really appreciate it.
I'm gonna let the battery recharche now, will post the results of it later

Thanks again!

 

[redbenjoe]

if you are just using your FM radio --and not using much volume or big bass --
a good 2 AH may all day

 

[reezlee]

It's not an fm radio, It's quite a beast that we're dealing with

(btw, the image is just from google)

 

[BoomboxLover48]

That is a very thirsty bird!

Keep the bass and volume low or else will drink all the juice from that 2AH in no time.

 

[reezlee]

Haha I'll try