Gel Cell for backup on an MP40?

[kwajtrader]

Has anyone tried simply wiring up a 12v gel cell to the 12v jack on an MP40W? Unless data is somehow being multiplexed on the two wire jack wouldn’t this just be a 12v battery jack with a specific charge rate when AC was there and current drain when AC was gone? I'm not sure why this wouldn't just work.

 

[jeep9783]

I don't know about that but when mine gets here i am just going to plug it into one of my cpu backups

 

[texhorns98]

Tagging along on this one. We've got a couple of electrical guys on here, I know.

 

[kwajtrader]

I bought a pack of "B" size connectors at Radio Shack which fit the jack and am thinking about hanging a 12v gel cell off of it and taking some current measurements. I'd like to know if anyone has blazed the trail ahead of me. My concern is that the controller has got some pretty fancy stuff going on with automatic sw upgrade and master slave communication (I'm guessing it's bluetooth given the range) so given the price of the battery backup it wouldn't surprise me if it had some RF interface/control going on.

 

[kwajtrader]

Does the battery backup unit have any type of control or interface or just the jack to provide 12 to the MP40?

 

[realfish]

kwajtrader;337249 wrote: Does the battery backup unit have any type of control or interface or just the jack to provide 12 to the MP40?

Just the jack to provide 12 to the MP40.

 

[rockdog]

sounds like a good Optima yellow top and a battery tender... I know it is more than the back up but it will last a LOT longer...

Jason

 

[kwajtrader]

But have you plugged it into an MP40W?

 

[kwajtrader]

I should have been more clear. I was asking if anyone had plugged in anything other than the ecomarine battery backup pack like a 12v battery or gel cell into the 12v jack.

 

[kwajtrader]

Well I finally tried it and it works. A plain old 12v spare gel cell running my MW40w. With AC applied (24v to other input) there is no current flowing to the gel cell. With AC removed the MP40 draws about 200ma and switches to battery backup mode (flashing green). My next step is to add a float charger.

 

[rockdog]

you beat me to trying it, I have no spare time. Glad to know it works, I will be doing the same thing.

Jason

 

[sailfish]

How much will all that cost you and how many hours do you think it will last?

Joe

 

[kwajtrader]

I had the 7A gel cell from an old UPS and I had to buy the connector from Radio Shack, so about $2.
As for the run time, based on this website
http://www.csgnetwork.com/batterylifecalc.html?cx=partner-pub-8018289210612122%3Ai26bw8-jsy2&ie=ISO-8859-1&q=&sa=Search&rbc=7&dr=.2&pn=1.1&crate=&tlifetime1=&mlifetime8=&tlifetime2=&tlifetime3=&tlifetime4=">http://www.csgnetwork.com/batterylifecalc.html?cx=partner-pub-8018289210612122%3Ai26bw8-jsy2&ie=ISO-8859-1&q=&sa=Search&rbc=7&dr=.2&pn=1.1&crate=&tlifetime1=&mlifetime8=&tlifetime2=&tlifetime3=&tlifetime4=</a>
at 7ah capacity and 200ma discharge rate I should be at 25% discharged after 10 hours. I need to run a few tests and see what actually happens.

 

[kwajtrader]

I've also got a 125hr deep cycle marine battery wired with a float charger driving a 400w inverter to power my main pump, so between the two I should be in reasonable shape for the better part of a day.

 

[acroholic]

I got me a 1200 watt mini generator from Pep Boys for $110. Used it once so far.
Dave