Battery life for Sirius Domes

h0ughy (David) · #1 03-12-2011, 09:14 PM

Well its a beautiful clear night, one of only a handful in the past 6 months. turned everything on -- and waited...... and waited... no dome response. so i tested everything i could - then i identified the culprit - the dome battery.

so i will have to wait to get new one. anyone else who has had this type of problem? is it worth wiring up 12v directly?

this is a pic of the battery

GTB_an_Owl (Geoff) · #2 03-12-2011, 11:35 PM

an old computer power supply should do it Dave

geoff

h0ughy (David) · #3 03-12-2011, 11:48 PM

Quote:

Originally Posted by GTB_an_Owl

an old computer power supply should do it Dave

geoff

now why didn't i think of that? though i do have one thought - have any of the other dome owners out there done that?

acropolite (Phil) · #4 03-12-2011, 11:52 PM

The problem with using a power supply is the starting current requirement for the motor which may be quite high. I'd be replacing the battery, they're only about $25-$30 for the size you have. I would also be investing in a suitable charger if the only charging option you have is the solar panel. Gel batteries aren't designed to be cycled to any extent, although you can get deep cycle variants. The charging requirements for Gel Batteries are quite specific, particularly if they are run dead flat so using a charger that is specifically designed for gel batteries will help prolong the life.

h0ughy (David) · #5 04-12-2011, 12:01 AM

Quote:

Originally Posted by acropolite

The problem with using a power supply is the starting current requirement for the motor which may be quite high. I'd be replacing the battery, they're only about $25-$30 for the size you have. I would also be investing in a suitable charger if the only charging option you have is the solar panel. Gel batteries aren't designed to be cycled to any extent, although you can get deep cycle variants. The charging requirements for Gel Batteries are quite specific, particularly if they are run dead flat so using a charger that is specifically designed for gel batteries will help prolong the life.

well i did wonder about that though the thought from Geoff was a good one? the constant wet weather and cloud i think has killed it - punishment for having a good time at astrofest i am sure

. the solar panel normally kept it healthy i though - and i know that this incessant weather has lead to a drop in the power - when i tested the battery it only had 6.2v to it was well and truly terminated

Tandum (Robin) · #6 04-12-2011, 01:03 AM

I run my home brew dome off a 12v 2amp supply Dave, as that's the one I found in the shed

I recon the motors are pretty similar. I notice it runs a little slower when the LED rope lights are also on but it still goes ok

I run everything else off the PC power supply.

allan gould · #7 04-12-2011, 03:56 AM

Dave
Funny u should mention this as I accidentally left my battery on once over night and its never been the same since and tonight its dead in its pants. A quick charge got it going again, but ill get a new one tomorrow

h0ughy (David) · #8 04-12-2011, 11:20 AM

Quote:

Originally Posted by Tandum

I run my home brew dome off a 12v 2amp supply Dave, as that's the one I found in the shed

I recon the motors are pretty similar. I notice it runs a little slower when the LED rope lights are also on but it still goes ok

I run everything else off the PC power supply.

thanks Robin - still might trial that?

AstroJunk (Jonathan) · #9 05-12-2011, 01:19 AM

Same problem here as well. The shutter can be left on all the time with out the battery suffering, but the rotation battery is an issue.

I now run the rotation motor off a 10 amp transformer. Anything else doesn't seem to get over the initial power surge. That motor is probably the same one they use for a 5m dome - its not subtle!

h0ughy (David) · #10 05-12-2011, 06:22 AM

thanks for that feedback Jonathan, late yesterday i went to super cheap auto and managed to pick up a 12v 12ah battery that just fits in the hole. the unit worked straight away afterwards. i will look in to a more permanent solution.

allan gould · #11 06-12-2011, 08:53 PM

Also replaced my battery with a deep cycle battery which will be better than that supplied as they are known to have their lifetime shortened by discharging it fully

midnight (Darrin) · #12 12-12-2011, 03:21 PM

Houghy, I noticed you have a Kemo charger there. I have 1 as well & they are good but pretty ordinary when overcast.

I ended up replacing mine with one from Silicon Chip and I am calculating a 40% power increase to the battery in overcast conditions as well as correct charging for the battery.

Most batteries in these situations can also be killed by overcharging. There are numberous charts out there but most require a specific charging map to greatly extend the life of your battery. We use bog standard 12V 7.2AH gell batteries in power stations for distributed emergency backups for cameras and fire systems etc for many years with regular deep discharging twice a week and they are still performing because the charger is specific to these types of batteries to prevent premature damage.

Discharging will also kill one very quickly too.

The Kemo is quite good but it can over charge the battery and struggles in low power situations (eg winter)

The kit is available at Jaycar and here is the link to SC
http://www.siliconchip.com.au/cms/A_112335/article.html

Good luck!

Darrin...

h0ughy (David) · #13 12-12-2011, 07:18 PM

Quote:

Originally Posted by midnight

Houghy, I noticed you have a Kemo charger there. I have 1 as well & they are good but pretty ordinary when overcast.

I ended up replacing mine with one from Silicon Chip and I am calculating a 40% power increase to the battery in overcast conditions as well as correct charging for the battery.

Most batteries in these situations can also be killed by overcharging. There are numberous charts out there but most require a specific charging map to greatly extend the life of your battery. We use bog standard 12V 7.2AH gell batteries in power stations for distributed emergency backups for cameras and fire systems etc for many years with regular deep discharging twice a week and they are still performing because the charger is specific to these types of batteries to prevent premature damage.

Discharging will also kill one very quickly too.

The Kemo is quite good but it can over charge the battery and struggles in low power situations (eg winter)

The kit is available at Jaycar and here is the link to SC
http://www.siliconchip.com.au/cms/A_112335/article.html

Good luck!

Darrin...

thanks for the technical input Darrin.

i bought the dome setup from Sirius observatories and that is their standard setup. i was unaware of the technical differences in the solar charging, but from what you have indicated, they are huge. i think with the bigger battery and a big "have you turned everything off sign" might have to do for now - i will see how it goes. Changing parts like that i try to avoid unless i really have to.