A reminder about charging your PowerTanks

[James]

At this time of year where many of us don't get out to do any viewing for a few weeks it's worth remembering to charge up your PowerTanks/batteries every 3-4 weeks as, in common with all lead acid batteries, your PowerTank's charge needs to be kept topped up to avoid damage. I thought I'd post this reminder to avoid any disappointment when the longer dark nights come round again...

Lead acid batteries lose charge even when not being used and allowing the battery to discharge power over several periods of use without recharging can lead to the situation where the battery cannot be charged with the supplied charger.

If the battery discharges too far this can permanently damage it, or at the very least considerably shorten its lifespan. To avoid this the battery must be charged before, and regularly during, periods of storage and after every use.

If your battery has drained completely or hasn't been charged after each period of use there is a chance it can be rescued by the use of a deep charger otherwise you may find it impossible to recharge at all - not something you want to find out as the longer nights come round again.

James

[beetlejuice]

At this time of year where many of us don't get out to do any viewing for a few weeks it's worth remembering to charge up your PowerTanks/batteries every 3-4 weeks as, in common with all lead acid batteries, your PowerTank's charge needs to be kept topped up to avoid damage. I thought I'd post this reminder to avoid any disappointment when the longer dark nights come round again...

Lead acid batteries lose charge even when not being used and allowing the battery to discharge power over several periods of use without recharging can lead to the situation where the battery cannot be charged with the supplied charger.

If the battery discharges too far this can permanently damage it, or at the very least considerably shorten its lifespan. To avoid this the battery must be charged before, and regularly during, periods of storage and after every use.

If your battery has drained completely or hasn't been charged after each period of use there is a chance it can be rescued by the use of a deep charger otherwise you may find it impossible to recharge at all - not something you want to find out as the longer nights come round again.

James

Thanks for the reminder James. Haven't used mine for while. Now where did I put the charger?

[Macavity]

As one now the proud owner of a Celestron one, I am intrigued. Is there any problem with putting the thing on charge TOO regularly? More a personal foible re. the PLETHORA of all things rechargable around here...

[johninderby]

Gel-cell batteries (as used in power tanks etc.) should always be charged after each use, as if one is put away flat it can actually be ruined after just a few weeks. When the charge in the battery gets too low some of the cells can reverse polarity and then there's no way to save it.

Cold also has a big effect on the battery. If the battery is fully charged and then kept indoors in the warm it can be stored for a year before it needs charging again. The worst thing you can do is to store the battery on a concrete floor in an unheated shed or garage, as even a fully charged battery can loose enough charge to permanently damage it in just a month or two.

Unlike ni-cad batteries gel-cells have no memory effect so you can give them a top up charge whenever you want. Preferably with an automatic charger, but even with a standard wall charger you would have to leave it on for several days to damage the battery.

John

[Sam]

Great thread James! I just plugged mine in, thanks for the reminder!!!

[Mark at Beaufort]

Thanks James for the reminder. I leave my two units in the garage and after reading John's (inderby) comments I think I need to reconsider their placement.

Mark

[gataki]

Thanks James and John, I knew I was supposed to do it but was worried I would overfeed it!

Liz

[paulestar]

I read this too late I charged mine last week for the first time in yonks (didn't realise I had to...it seemed fine!), and just took it out of the garage. You guessed it...it's flat already

[AztecastroMcJ]

thx 4 tips

not had needs charging light appear yet on mine

if the needs charging light comes on should i recharge immediately ?

i regularly top mine up after using and seems to last for hrs even with me skewing alot

also can i use the tanks charging adapter lead to connect to scope direct to mains ?

[Jarndyce]

Thanks for the heads up, James.

I've just put mine on charge. I think I've been really lucky with mine so far. They last for weeks and weeks with my CG5, but then I don't think it draws much juice - non goto version.

Having said that, the charge light never goes out and shows fully charged, even if left on for 24hrs.

[James]

As one now the proud owner of a Celestron one, I am intrigued. Is there any problem with putting the thing on charge TOO regularly?

That really depends on the charger... the ones that come with PowerTanks should stop charging once it's full but I'd still prefer to disconnect the charger once the battery indicates it's full. If you have a 3 or 4 stage charger (heading into £40+ territory but well worth it) then these usually switch to 'float charging' when the battery is full and they just provide a trickle to keep it topped up and can be left attached indefinitely. You're right to think about it though - lead acid batteries don't like being over charged any more than they do being undercharged.

also can i use the tanks charging adapter lead to connect to scope direct to mains ?

No, I wouldn't do that! You'd need an AC adaptor of some sort. I use a Maplin power supply and a lead with ring tongue connectors to my scope. You can also use a DC-AC adaptor which is usually available in camping shops and the like, for example this one (which doesn't show the 12v socket )

[vincentnm]

If your battery has drained completely or hasn't been charged after each period of use there is a chance it can be rescued by the use of a deep charger otherwise you may find it impossible to recharge at all - not something you want to find out as the longer nights come round again.

James

Mine's drained and refuses to re-charge. How can I rescue it? What is a deep charger?

Thanks,

Vincent.

[James]

You may need to get the battery out of the PowerTank to do this but a charger like these may help:

CTEK

Optimate

I use the CTEK myself and the Optimate is highly rated by some members on here.

It's not guaranteed to work of course as it's dependant on the state of the battery but it'd probably the batteries last chance.

Fingers crossed!

James

[MikeP]

Here's a picture of the battery taken from one of my Maplin jump starters. I took them out and threw the cases away. I charge with the Optimate charger.

Mike

[vincentnm]

You may need to get the battery out of the PowerTank to do this but a charger like these may help:

CTEK

Optimate

I use the CTEK myself and the Optimate is highly rated by some members on here.

It's not guaranteed to work of course as it's dependant on the state of the battery but it'd probably the batteries last chance.

Fingers crossed!

James

Thanks James. The charger's as expensive as my battery. I think its wise to just invest in a deeep cycle batter + charger combo.

Cheers

Vincent.

[Highflight]

Just a quick post in case anyone is looking for a 'jumpstarter battery pack', Wickes are selling them in their Superstores (not the small stores) for £14:68p. I did put a link up the other day, but it's not valid any more. I think the shop I put the link to had sold out, but you can get them, complete with charger and air compressor for pumping up airbeds after a long night session.

Hope this is of help.

Chris.

[Highflight]

Update: Rolson 12V Portable Jump Start and Compressor only £34.99 - Buy Online or Call 0800 310 2852

[fmeireso]

Nice thread. I 'll check mine. I did not know it discharges when I am not using it...

[James]

Time to bump this one methinks

James

[Nermal]

Thinking about getting one of these while they're on offer - 5in1 Jumpstarter with Digital Air Compressor : InCar Battery Chargers and Compressors : Maplin

Maybe useful for people with dead powertanks

Edited July 12, 2010 by Nermal

[neilm]

I'd recommend Opimate, been using one if these on motorcycle batteries for years. You can just plug it in and leave, the charger regulates itself and just keeps the battery topped up.

[Sparrow]

I'm so glad I read this thread. Having forgotten to charge my power tank for a few months earlier this year - you've guessed it - it wouldn't charge up and was almost flat. Having read this thread last night I went and connected the power tank to the car battery charger which has a deep cycle trickle charge. It's now fully charged and working great again. Thank goodness - thought I was going to have to blow my wife's bike tyres up the old fashioned way. I've now put a weekly reminder on our calender to charge it.

BTW - din't need to dismantle the power tank - the jump leads on it connect directly to the battery so I was able to just hook the charger up to them.

[Black Knight]

I've now put a weekly reminder on our calender to charge it.

That sounds like a great idea to me

[BinocularSky]

Just a thought: Is there any reason that I shouldn't use a 1.5W solar trickle-charger to keep a powertank topped up? (I presume they have cheap SLAs inside.)

[Geoffrey]

thanks for the reminder have just put on charge said needs charging glad i read this thred