Medtronic 670G: What Battery Is Best?

I am currently using the 530G and plan to, in the near future, upgrade to the 670G. The 670G obviously has more screen action and sensor communication is much more important, so I want to use the best batteries possible. I have been using Duracell LR03 (which is what the 530G instructions say, and is Alkaline), but the instructions for the 670G say that for best results to use Lithium FR6. I have been unable to find AA Lithium FR6 batteries on Duracell’s site, so I plan on getting them from Energizer. But the instructions also say the pump accepts “fully charged AA NiMH (HR6) nickel-metal hydride rechargeable battery”, but in the past I have been told to never use rechargeable batteries with my pump (not that I was planning to this time either), so I was wondering why they even mention them here. But I guess my important question here is whether anybody has any comments or notable experience difference in using Lithium (FR6) vs Alkaline (LR6)? Is one of them really better?

I can’t comment on experience with the difference between lithium and alkaline batteries in the 670G pump. Since I use an automated insulin dosing system that communicates wirelessly between the pump and the phone app every five minutes, I have done a comparison between alkaline and lithium.

My MM 722 pump uses one AAA battery. If I use an alkaline battery, it only lasts a few days. An Energizer lithium battery will last a week or so. I buy them in packs of 20 on Amazon. Perhaps the 670G, being a later developed system, optimizes battery usage better than my system. For convenience, I would select the lithium battery.

Does the 670G report the percentage of battery capacity remaining on the home screen? Does it warn you when it’s getting low?

I don’t have the 670G either, but I’ll comment on batteries in general.
An alkaline battery has a slightly higher voltage than a NiMH rechargeable. So essentially the NiMH is like a slightly used alkaline. But that’s only at the start. Alkalines quickly drop voltage during use, while NiMH stay much more constant during their longer lifetime.

I can think of few applications where NiMH would be a bad choice. The exception would be a very low drain application like a TV remote. If an alkaline lasts a year, why bother with recharging!

NiMH will not HARM your device in any event. You are trading the considerably longer life for the hassle of recharging. Lithium batteries are the best of all as far as life, but they are generally more expensive and, of course, need to be replaced eventually.

670g only reports High/Med/Low in the status window. On the home screen, its Green/Yellow/Red. I would prefer a percentage.

Alkaline vs Lithium cells I’ve tried. No data to support it, but the Lithium batteries last considerably longer than alkaline… as expected. But in the long run, i’m not sure you save any money by using lithium over alkalines.

This is an incorrect statement - voltage is IRRELEVANT

It is all about how they perform with a load

I won’t bother to get into it - all the info is on the net

That was not a helpful statement. It’s fine to disagree, but a supporting statement would be helpful. If you said that current delivery was the important factor, I could agree with that. But my statements about longer life are correct. Some devices have a low voltage cutoff, which the alkaline will reach more quickly.

I use NiMH batteries in both flashlights and electronic flash equipment. In both applications, they give superior performance over alkaline.

I never stated NiMH were not better - I use eneloops for everything but the pump my wife uses as I believe medtronic does not like them in the 570 because of half life or whatever - I have never tried one in her pump as the others last at least 3 weeks

I am surprised they are OK in the new pump

Your statement that a NiMH is a sightly used alkaline is the problem

A fully charged eneloop is going to meter over 1.5V anyway

My advice to folks would be stick with the high quality AA and not burn money on lithium

If you want to use NiMH you need a good charger with Negative delta V termination - which most probably have

My apologies if I offended you

candlepowerforums is the place to go for battery questions as it is the largest forum on earth for such questions

tons of info if you just want to browse

If anyone is going to use rechargeables be sure they are made in Japan and not China

Not offended Tony. I just wanted more detail about what was incorrect. I’ve spent many happy hours in the past on Candle Power Forums. When I was still doing part-time wedding photography it was important to have the right batteries.

I’m surprised about the comment about half life. While not all NiMH are LSD (low self discharge,) I would not expect that to be a significant problem over a time span of a month. It’s certainly true that the Eneloops and other LSD batteries will be closer to fully charged six months to a year later.

Maybe half life is an incorrect term - I thot that is what medtronic stated - A LOT LESS TIME AFTER LOW BATT WARNING

I think the problem is you got a day when low batt goes off with alka and a lot less time with the eneloops IN THE OLDER PUMPS ANYWAY

I believe that is their statement although I have not gone to find it

Because the discharge curves are different between the two battery types, I would expect the remaining time after the warning to be less for NiMH. But I think it’s also true that the time until the warning is much greater with NiMH.

If I were going to try this, I think I might have two sets of NiMH. I would establish about how long a set lasts — granted there would be some variation with demand. And I would just change batteries on a schedule, even without the warning. Or I could just carry a spare set with me.

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Exactly - that is great advice - x amount of time and be done with it - for rechargeables

[Originally posted my response as an individual reply, which was unintentional. It’s to the OP.]

Not sure about what definition of “best batteries possible” you had in mind, @njsokalski, but I use the rechargeable Eneloop Ni-MH in my 670 and they work fine. I carry a spare in my glucose meter case. You get enough warning on the pump in any case when the battery is running low.

Be prepared that whatever batteries you choose to use, the 670 WILL suck them down much faster than what you might be used to with the 530. (As you are probably guessing correctly with the mention of “more screen action and sensor communication”.)

I’am on the 640G.

The lithium will last for 3-4 weeks. = 24 days

The NiMH will last mee for 2 weeks.

The alkaline will last me 1 week.

Al this is without the use of a sensor.

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David Burren studied the lifetime of a variety of AAA batteries in the Medtronic Veo 554 pump used for looping with openAPS.

I decided to try eneloop Pro NiMH rechargeable batteries in my new 670G as I use them in my high-draw DSLR camera system and external flash units. My nurse pump educator encouraged me to try them and ket her know my experience with them. Nine days in and the status screen says pump battery: medium. Having said all of that these batteries are pretty heavy. When I go on vacation, however, I’m planning to use Lithium batteries as they feel to me significantly lighter and I won’t need to worry about bring a charger. I will be “green” once back at home!

The black top Duracell 2400 are really eneloops I am pretty sure - I use them in a Fenix Led Light and they are awesome

I have a 630G and I think the manual gives the same instructions. Medtronic has always advised Energizer AA alkaline for the pumps I’ve had.

This time, I tried a lithium battery. It didn’t work. Maybe I had a bad batch, but I didn’t want to take any chances. Went back to alkaline. I then bought a AA NiMH charger and batteries. However, when I put one of these batteries in my pump, even after reaching full charge, my pump indicates a “yellow” battery level. That really didn’t instill confidence, so I went back to the alkaline.

That’s my 2 cents.

I don’t use a pump, so I don’t really have a horse in this race. But I believe that a quality NiMH battery on a quality charger is almost always going to give better performance and last longer than an alkaline battery. And that’s regardless of what an indicator on the pump says.

I would avoid off-brand NiMH batteries and chargers and in particular, rapid one hour chargers. Eneloops have a well-deserved reputation for quality, but there are others too.

As others have noted, NiMH batteries provide better performance in a number of high-drain applications like electronic flashes and flashlights. Pumps would be no different.

Good advice - I have had great luck with Duracell, esp the 2400 with the black top - I believe they are re branded envelops anyway - I would avoid all others and as DiabetesOldie stated - fast chargers

I have this one and it works great