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CCR and rechargeable batteries

Posted: Tue Mar 09, 2010 5:03 am
by HydroGirl
Is anyone using rechargeable batteries?

I have a classic inspiration, I am considering rechargeable batteries.

Any suggestions?

Thanks, Sandra

Re: CCR and rechargeable batteries

Posted: Tue Mar 09, 2010 6:34 am
by loanwolf
It has always been not recommended for use in a CCR. Rechargeable battery's carry there current longer then just drop dead never giving you a decent amount of time to let you know when they are low. Shearwater and several other computer manufactures will not use a rechargeable battery for the same reason.

Re: CCR and rechargeable batteries

Posted: Tue Mar 09, 2010 9:58 am
by camerone
There was some discussion on the Inspiration mailing list a while back about this. A few people were saying that they had good results with the rechargeable CRP2 batteries. I don't personally use them, but I don't see it as a tremendous problem if you are careful and know what you're doing, particularly since the system has dual redundancy with a set of true dual controllers, not a primary and "monitor-only" type of secondary like some units have.

FWIW, the internal battery metering circuits are calibrated for the discharge curve of a couple of specific brands of CRP2 only...cheaper no-name ones - primary cells, not rechargeable - have caused battery issues in the past. I wouldn't trust the on-board battery monitoring, but the discharge profile of those cells should be identical to the primary cell profile...i.e. little real warning on the handsets before they start to go TU.

So, YMMV. If I were going to use them, I would treat it like I used to treat the odometer as a fuel gauge on an old motorcycle...be sure to top frequently, set the stopcock back to "main" when you do top it off, and every so often, analyze your rechargeable with a battery analyzer to see the true lifespan in the cell.

I'm sticking with the primary cells - I get about 10-15 hours out of each of them as primary, plus the equivalent as secondary, so that's about $1/hour in dive battery time. Pretty cheap. If you upgrade the solenoid ($100-ish from APD) to the new version, it consumes a lot less power, and you'll get significantly longer life out of your cells. You're a heavy diver, so that should pay for itself in a year or two.

Re: CCR and rechargeable batteries

Posted: Tue Mar 09, 2010 3:56 pm
by Gill Envy
One thing you don't want on a rebreather is a sudden drop in battery power, which is what invariably happens with rechargeables. The other nasty thing that can happen is that on occasion, for reason's unknown, they don't take a charge and act OK at first and then die completely, prematurely. I've seen this happen.

I personally would not recommend using rechargables for life support, it's the one place I don't use them.

I tend to favor efficient electronics and I had some nasty experiences years ago with eCCR's so i've been using a Shearwater manual set up ever since... it's amazing how long batteries last when you leave out the Solenoid! I don't have in issue with buying a new battery once or twice a year.

There are some electronics like the HammerHead which eat batteries, with recommendations to change out the battery with every dive! good god, that's where I'd consider a rechargeable where you are swapping out on every dive and have a fully redundant po2 monitor... then again I'd have gone for a different breather in the first place.

if you choose to go with rechargables, realize not all are made equal... there is a huge difference in how long they last from brand to brand.

g

Re: CCR and rechargeable batteries

Posted: Wed Mar 10, 2010 4:22 am
by HydroGirl
Thanks for the info,

It just seemed to me that I was going thru batteries every other weekend.
It sounds like it may have been my solenoid.
The unit is getting its annual service and I will make sure to request the solenoid upgraded.

Does anyone have a good source for bulk batteries?

Re: CCR and rechargeable batteries

Posted: Wed Mar 10, 2010 10:09 am
by camerone
HydroGirl wrote: Does anyone have a good source for bulk batteries?
Four no-names for $12.95:
http://www.batteryspace.com/4pcs6v1300m ... amera.aspx

I generally use Energizers - no experience with these guys, but the price is good:
http://www.onlybatteries.com/showitem.a ... leShopping

If you want Kodak (dunno who they're rebranding):
http://www.freestylephoto.biz/8486243-K ... y?sc=24100

All in all, pretty cheap, and better than the $10-$15 that the drugstores and dive shops want to charge.

Re: CCR and rechargeable batteries

Posted: Wed Mar 10, 2010 1:11 pm
by HydroGirl
Cool, Thanks

Re: CCR and rechargeable batteries

Posted: Sat Mar 27, 2010 7:29 am
by Gill Envy
If you are talking CRP2's, I'd highly recommend going with Duracell, their decay characteristics worked particularly well with our Visions and there are some crap versions out there. Good deals can be had on the internet, I'd just look out for not getting scammed. I purchased in bulk and with one of the shipments I ended up getting a pile of Duracells that were not in their original packaging and were apparently used to varying degrees, some failing right out of the bag.

g


HydroGirl wrote:Thanks for the info,

It just seemed to me that I was going thru batteries every other weekend.
It sounds like it may have been my solenoid.
The unit is getting its annual service and I will make sure to request the solenoid upgraded.

Does anyone have a good source for bulk batteries?

Re: CCR and rechargeable batteries

Posted: Sat Mar 27, 2010 8:48 am
by HydroGirl
Thanks for the advice.
I was worried about getting scammed on the internet, so I bought them from rebreatherexpress.
I know I could have done better but I have done business with them before with no problems.

New question:
Now that I have a supply for a year, where do I store them?

Re: CCR and rechargeable batteries

Posted: Sat Mar 27, 2010 10:08 am
by Gill Envy
a cool dry place out of the sun should do the trick, they should be good at least until the expiration date.
cheers,
g

Re: CCR and rechargeable batteries

Posted: Sun Mar 28, 2010 7:48 am
by HydroGirl
I have been keeping my batteries and sofno in my garage.
Most of the year it is a cool, dry, dark place. Except for the couple of weeks in the summer when it does remind me of Florida.
Someone told me to keep batteries in the refrigerator, I guess this does make sense since it is a constant temperature.

Where do you guys keep them?

Re: CCR and rechargeable batteries

Posted: Sun Mar 28, 2010 10:21 pm
by Gill Envy
I tried the fridge but the condensation seems to eventually make it's way in... and it seems like overkill, IMHO.
g