Power tank replacement

[bish]

Hi all,

My 10 year old Celestron 17AH power tank has packed in. I only need something for dew control (2 strips and a hair dryer).  Can anybody suggest a cheaper alternative?

thanks

Bish

[JamesF]

Could it just be the battery?  If so it might be possible to replace it.

James

[DaveL59]

a 17AH battery costs around £27-£30 off ebay so if it still works electrically but isn't holding charge for long that may be the best way forward. Also check the charge/float voltages while its open as too high will shorten the battery life. Compare to the spec on the battery and where possible adjust to the low end of the range specified, will increase charging time and maybe lose a few % or total capacity but should improve lifespan. I'd guess tho that 10 years the voltage settings are probably fine, but worth checking anyway. Same issue with UPS systems where they are on float 24x7 until they are needed, I tweaked my APC's down after the first sets lasted just under 3 years, not good when there's 5 of them.

[bish]

Thanks both for your help. I assumed it would need replacing, didn’t think I could just change the battery in it.

[Trikeflyer]

I changed the battery in my skywatcher 7 ah with a battery off the web. Works fine now. Just be careful when dismantling so you don’t lose or damage any bits. I think it will be fine.

steve 

[DaveL59]

good advice there, take your time and go carefully.

Suggest too remove any rings watches etc and be careful with screwdriver or pliers. While they don't look that big these batteries can drop 100A across the terminals quite nicely and cause a nasty burn/injury if shorted. Quite likely your current battery has a cell that has failed so once charging has completed and its disconnected it'll drop quickly from 13v to 11v as the failed cell can't deliver the goods. The battery as a whole tho can still give a kick if shorted. 

[johninderby]

You can make a small welding machine with one of these batteries so yes they do contain a surprising amount of power.

 

[bish]

Thanks for the advice, I will be careful.