Car battery

[gtis]

Hi

can I use a car battery for my dew controller and straps

As I don't want to buy another charger if I buy a leisure battery as I can use my car battery charger with the car battery

[faulksy]

you can use a car battery no problem. but don't discharge to much or it fail

a leisure battery can be charged of a car battery charger, they are very similar in that respect

[Daz69]

Car batteries aren't designed for long periods of continual drain, just leave your side lights on and see how quick it will kill your battery. They are designed for quick punch high current drain as in a starter motor. Depending on how much drain your straps use over a given time will depend how quickly that battery will go flat. 

If this is to be a regular use, then you are really better off getting a deep cycle battery for this sort of application. They don't drop voltage as quickly until they reach the end of their charge, then drop suddenly. That's why they're used in kiddies toy cars/trikes and mobility/golf carts etc. You can get say a 9 or 10Ah deep cycle battery for £20 off the bay. I use them in portable 12v power boxes for fishing and emergency use. I will also be using one (or two together to give me 18Ah) for my scope's power supply. Make sure it is a deep cycle battery which is normally black, and not the cheap "alarm" or PSU type battery, which are normally grey in colour. Something like this http://www.ebay.co.uk/itm/VIPOW-12V-10Ah-Deep-Cycle-Maintenance-Free-Sealed-AGM-Gel-Battery-Scooter-Yacht-/121500443251?hash=item1c49fda273:g:qN4AAOSwPYZU7FYD The bigger you can get the better, but the prices can rise quite steeply. Also, as your needs grow, perhaps with powering or charging a tablet/phone then it will still be capable. I can go fishing for 48 hours and power a 18" LED strip light, charge my iphone and tablet and still have 10v at the end. 

So roughly this battery will give 10 amps per hour or 5 amps for 2 hours, etc. until it drops off. Like any rechargeable battery, drop it too low or too many times, and you'll lose the battery. Never go below 9.6v is my limit.

A cheap 3 or 4 stage computer controlled charger can be had for around £20 as well which are ideal for deep cycle batteries. My large caravan battery is left hooked up on my 4 stage charger every day when it's not in the 'van. Something like this will do you nicely http://www.ebay.co.uk/itm/MARXON-12V-4-Amp-3-Stage-VRLA-Golf-Battery-Charger-/132099616076?hash=item1ec1c02d4c:g:tygAAOSw4CFYp0AB Recharge overnight ready for the next day! This will get your battery to around 13v off charge.

Hope this helps.

[gtis]

12 hours ago, Daz69 said:

Car batteries aren't designed for long periods of continual drain, just leave your side lights on and see how quick it will kill your battery. They are designed for quick punch high current drain as in a starter motor. Depending on how much drain your straps use over a given time will depend how quickly that battery will go flat. 

If this is to be a regular use, then you are really better off getting a deep cycle battery for this sort of application. They don't drop voltage as quickly until they reach the end of their charge, then drop suddenly. That's why they're used in kiddies toy cars/trikes and mobility/golf carts etc. You can get say a 9 or 10Ah deep cycle battery for £20 off the bay. I use them in portable 12v power boxes for fishing and emergency use. I will also be using one (or two together to give me 18Ah) for my scope's power supply. Make sure it is a deep cycle battery which is normally black, and not the cheap "alarm" or PSU type battery, which are normally grey in colour. Something like this http://www.ebay.co.uk/itm/VIPOW-12V-10Ah-Deep-Cycle-Maintenance-Free-Sealed-AGM-Gel-Battery-Scooter-Yacht-/121500443251?hash=item1c49fda273:g:qN4AAOSwPYZU7FYD The bigger you can get the better, but the prices can rise quite steeply. Also, as your needs grow, perhaps with powering or charging a tablet/phone then it will still be capable. I can go fishing for 48 hours and power a 18" LED strip light, charge my iphone and tablet and still have 10v at the end. 

So roughly this battery will give 10 amps per hour or 5 amps for 2 hours, etc. until it drops off. Like any rechargeable battery, drop it too low or too many times, and you'll lose the battery. Never go below 9.6v is my limit.

A cheap 3 or 4 stage computer controlled charger can be had for around £20 as well which are ideal for deep cycle batteries. My large caravan battery is left hooked up on my 4 stage charger every day when it's not in the 'van. Something like this will do you nicely http://www.ebay.co.uk/itm/MARXON-12V-4-Amp-3-Stage-VRLA-Golf-Battery-Charger-/132099616076?hash=item1ec1c02d4c:g:tygAAOSw4CFYp0AB Recharge overnight ready for the next day! This will get your battery to around 13v off charge.

Hope this helps.

Thanks something to think about

i have four 7ah grey type batteries 

i will see how long they last, got them from work  so they don't own me anything 

I was thinking about this one

https://www.amazon.co.uk/gp/aw/d/B0170A36QM/ref=mp_s_a_1_13?ie=UTF8&qid=1487427507&sr=8-13&pi=AC_SX236_SY340_QL65&keywords=leisure+battery

[Gina]

That's little more than a decent car battery - good price  

[Daz69]

Yep that'll be even better than a smaller one, as you'll get more nights from it without charging. Also worth getting one of these (they can be found in red too) http://www.ebay.co.uk/itm/DC-3-30V-Blue-LED-Digital-Display-Panel-Voltmeter-Voltage-Gauge-Car-Motor-UK-/152069880968?hash=item2368123c88:g:S20AAOSw6kxXIWdD  just to simply hook up to check what's left, saves you guessing. Just remember you'll get a slightly lower reading if you're using a heater strap at the same time, best to let the battery rest 10 mins before checking. Stick inside a small plastic project box with pos and neg wire coming out via a momentary push switch http://www.ebay.co.uk/itm/Miniature-Momentary-Push-to-Make-Switch-Mini-SPST-/251697459778?var=&hash=item3a9a567242:m:m6D5J_-whwECWoVoS-0iDxQ and attach it to the battery with velcro. Jobs a good'un!

[gtis]

15 hours ago, Daz69 said:

Yep that'll be even better than a smaller one, as you'll get more nights from it without charging. Also worth getting one of these (they can be found in red too) http://www.ebay.co.uk/itm/DC-3-30V-Blue-LED-Digital-Display-Panel-Voltmeter-Voltage-Gauge-Car-Motor-UK-/152069880968?hash=item2368123c88:g:S20AAOSw6kxXIWdD  just to simply hook up to check what's left, saves you guessing. Just remember you'll get a slightly lower reading if you're using a heater strap at the same time, best to let the battery rest 10 mins before checking. Stick inside a small plastic project box with pos and neg wire coming out via a momentary push switch http://www.ebay.co.uk/itm/Miniature-Momentary-Push-to-Make-Switch-Mini-SPST-/251697459778?var=&hash=item3a9a567242:m:m6D5J_-whwECWoVoS-0iDxQ and attach it to the battery with velcro. Jobs a good'un!

Thanks for the links that's my next project, would you put the battery in a box as well

[Daz69]

3 hours ago, gtis said:

Thanks for the links that's my next project, would you put the battery in a box as well

Not necessarily. Depends on if you were thinking of adding extra ports for things like dew bands, power sockets etc, something like I built which can be found in this forum. Also if you're likely to bash it about (Not being rude but some people can be heavy handed) then a box might be a benefit to protect it. I think the boxes are around £25, so depends on budget really.

[SonnyE]

I use a sealed Lead-Acid AGM deep cycle battery to run my mount and CCD camera, and now more. Focuser, USB3 hub.

My reason was because after two failures of my mount's motor control board, I decided to feed it only 12 volt pure DC power like you only get from a battery. And I happened to have the one I'm using on hand anyway. So far, no more failures.

I don't need dew heaters where I live very often. I've tried making some, but they fell by the wayside and got packed away.

One thing I find with my AGM battery is it lasts for days and days before wanting for charging. Do check on what type charging your battery you get wants for. I have a charger that has a setting for Regular, Deep Cycle, or AGM type batteries.