SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Thanks a lot Rain Bird...I'm not paying $10 to talk to a customer service rep on your technical services 800 line when the people who write your manuals suck %#@.

I need to replace the rechargeable battery in my controller since it will no longer power the clock for any reasonable length of time with the controller unplugged.

The battery looks like a 9 volt battery, but the printing on it states it is 7.2 volts. The controller's manual states: "The replacement battery must be a 9-volt rechargeable NiMH battery." The Rain Bird web site is of no help on the specs of this battery.

Today on my lunch hour I go to the local specialty battery store and they have two similar batteries...one is 8.4 volts and the other is 9.6 volts (both NiMH). I am told there is virtually no call for the 7.2 volt version and it is very hard to find. The clerk is hesitant to recommend a voltage higher than the OEM battery and I can understand that.

My gut feeling is that the 8.4 volt one will work just fine, but I really don't want to damage the controller.

The parts and accessories section of Rain Bird's online store does not list a back-up battery. I tried calling the store, but apparently they don't have much for staff as the call eventually routed to voice mail with the only option to leave a message and they would call me back. I would be extremely happy to buy OEM...IF I COULD FIND ONE!

I hate to disagree with the professionals, but I am virtually certain that a 9.zero rechargeable NiMH battery does not exist (like I was told at the battery store). Think about it, every NiCad or NiMH battery is a multiple of 1.2 volts. These batteries are made up of multiple cells and each cell is 1.2 volts, hence cordless power tools are 12v, 14.4v, 15.6v, 18v, 19.2v. I believe the chemistry of the rechargeable cell is what determines (or limits) its voltage.

The battery I took out of the controller is a Varta brand (from Germany) and is labeled "AccuPlus Ultra", 7.2 volts. I don't ever remember replacing this battery in the past, so I am 99% sure it is what came with the controller from Rain Bird. The controller by the way is an ESP-12LX+ (the manual is copyrighted 2001 and I think the irrigation system was installed in 2005).

Since the manual plainly states, and I quote, "The replacement battery must be a 9-volt rechargeable NiMH battery.", I am gonna go with the 8.4 volt I found at the battery store. Think about it, 8.4 is LESS than 9.0 volts, so it shouldn't fry the circuitry, and it is at least 7.2 volts which is what was being utilized in the past. Makes perfect sense to me.


And when you winterize systems, you should leave the controller plugged in (but turned "off") to keep the back-up battery charged. Repeatedly running the battery completely flat will kill them much sooner.


Thanks again for your thoughts on this.

Thanks Mitchgo. I searched this web site, Rain Bird, and eBay. I figured if it existed, eBay would have it.

Makes me want to take my VOM to these batteries and see what exactly they put out for volts.

Thanks to both you and Wet Boots for hanging out on this site and conversing with us homeowners.

My "9 volt" Energizer rechargeable NiMH came in the mail today.

http://www.atbatt.com/product/6878.asp


In teeny, tiny little print (had to put on my reading glasses) on the back label of the battery itself..."8.4 volt".