p.1 #1 · Anyone use high voltage AA rechargeables?
I'm looking to move away from 1.2V rechargeable nimh batteries for my triggers and (my one-and-only on camera) flash. General recharge performance is what I'm looking to upgrade.
I'm looking at various 1.5V and 1.6V rechargeable alternatives, but am seeing mixed reviews.
Does anyone use this type of battery and if so, which type/brand do you like? I'll buy another set of Eneloop Pros if I absolutely have to, but after about 15 years with this type of battery, I'm ready to upgrade to something that puts out a full 1.5 or 1.6V.
p.1 #3 · Anyone use high voltage AA rechargeables?
deepbluejh wrote:
I'm looking to move away from 1.2V rechargeable nimh batteries for my triggers and (my one-and-only on camera) flash. General recharge performance is what I'm looking to upgrade.
I'm looking at various 1.5V and 1.6V rechargeable alternatives, but am seeing mixed reviews.
Does anyone use this type of battery and if so, which type/brand do you like? I'll buy another set of Eneloop Pros if I absolutely have to, but after about 15 years with this type of battery, I'm ready to upgrade to something that puts out a full 1.5 or 1.6V.
Flash units are specifically designed for the 1.2V NiMH cells. The higher voltage cells typically have limited current capability (higher impedance) and lower Wh capacity. They are most suited to devices that are voltage dependent, not current dependent.
p.1 #4 · Anyone use high voltage AA rechargeables?
blob loblaw wrote:
just wondering what is it that after 15 years of no issues you have a great need for 1.5V you didn't have before
I'm tired of my flash triggers always reading half empty, even when the batteries are "full". Plus... my current cells are getting old and tired. Looking to buy new ones and looking for something better.
Also... "no issues" have been a stretch. I've always hated AA batteries (vs lithium ion). Upgrading to higher power cells would be an improvement at least.
p.1 #5 · Anyone use high voltage AA rechargeables?
Can you post a link to the AA cells you are considering?
Generally at medium to high current drains there is not see much more than 3Wh in practice from an AA cell, and often less depending on the application cut-off voltage. That goes for any battery chemistry, though lithium Wh/kg is higher of course and lithium Wh can be higher at low drains. Advantages of lithium increase significantly with cell volume. AA is not a very efficient size.
Since lithium ion battery cells have a voltage of around 4.2V (fully charged) to 3V (discharged) with a nominal voltage of 3.6V to 3.7V, the way these types of lithium AA batteries work is that they have an internal voltage regulator that steps down the voltage from the battery cell and outputs a constant 1.5V.
This has its pluses and minuses. On the upside you get a very consistent full power voltage from the battery. This is great for some devices whose performance is voltage dependent, like devices with DC motors, as these will always run at full speed (rather than slowing down as the battery depletes as with alkaline or NiMH cells). Also can work well in some flashlights, delivering consistent brightness while in operation.
The downside is that there is zero useful indication of remaining battery life. From the device perspective, the batteries essentially just go from 1.5V to 0V once the internal cell is depleted and no longer providing current (the battery's internal electronics probably has a cutoff voltage at which this occurs to protect overdischarge of the cell). But in any case, there's no gradual voltage decline that allows the battery life meter in any device to work properly, so the batteries effectively just go straight from 100% power to dead when they run out of juice.
So the only way to really have any idea of how much runtime you have left is if you know the power draw of the device and can calculate how long you have used it for so far. But this only works for devices with a fairly consistent power draw. If the power usage of the device varies, you are pretty much guessing at that point.
Another consequence of the internal electronics in these 1.5V lithium rechargeables, is that these batteries typically require specialized chargers, as they don't behave exactly like traditional lithium ion cells which would typically be charged at around 4.2V. Many of the 1.5V lithium ion rechargeables charge at 5V to 6V instead (hence the built-in Micro USB port on some models).
In terms of overall battery capacity, one thing to note is that many of the 1.5V lithium ion rechargeable manufacturers seem to report the battery capacity in milliwatt-hours (mWh) rather than milliamp-hours (mAh). Which can easily lead one to believe that these 3000 mWh rated AA lithium ion batteries have higher capacity than NiMH or other alternatives. But higher quality NiMH rechargeables, which are 2500 mAh x 1.2V also are rated at about 3000 mWh. So the published capacity of the lithium-ion AA batteries isn't any higher.
And at least from the EBL 1.5V lithium ion AA rechargeables I have tested, the actual capacity is lower than what is advertised. They are really more like 2300 mWh (about 1700 mAh @ 1.5V) which is actually less capacity than the higher quality NiMH rechargeables like the Eneloop Pro AAs which actually achieve their 2500 mAH (or about 3000 mWh) rated capacity in many cases.
This testing was done with a constant power draw of about 600 mW or 400 mA @ 1.5V (which is roughly about a 0.2C discharge rate based on their rated capacity). This yields an overall battery runtime of just under 4 hours. It's possible that under different power draw patterns the batteries would perform slightly differently. For reference, under the same kind of 600 mW power draw the 2500 mAh Eneloop Pro AAs run for closer to 5 hours which is about what you'd expect given their rated capacity.
So to summarize, the takeaways for me were:
- use 1.5V lithium rechargeables in devices that don't turn on or operate at all with lower voltage (1.2V) rechargeable batteries
- use 1.5V lithium rechargeables for devices where you want to run at full power all the time (motors, lights, etc.) and don't care about the device dying without warning when the battery runs out
- use NiMH rechargeable batteries for pretty much everything else
Sep 28, 2021 at 06:48 PM
AmbientMike Offline • • • • • • [X]
p.1 #12 · Anyone use high voltage AA rechargeables?
deepbluejh wrote:
I'm looking to move away from 1.2V rechargeable nimh batteries for my triggers and (my one-and-only on camera) flash. General recharge performance is what I'm looking to upgrade.
I'm looking at various 1.5V and 1.6V rechargeable alternatives, but am seeing mixed reviews.
Does anyone use this type of battery and if so, which type/brand do you like? I'll buy another set of Eneloop Pros if I absolutely have to, but after about 15 years with this type of battery, I'm ready to upgrade to something that puts out a full 1.5 or 1.6V.
Eneloops are low self discharge batteries i.e. they are made to sit on the shelf and hold charge.
If you can keep up with the charging you can get significantly more power. I had delkins one time rated at 2900 ma/h, energizers 2600 mah I think Eneloops 2000 mah. IIRC So you can get significantly more charge, 30%-45%, if you can keep up with the charging. You might need to charge the higher capacity right before the wedding even the energizers seemed to last months though. EDIT: The eneloop pros rated at 2550 mah so this might not be as true anymore. Looks like energizer is 2300mah and last 5 years Still you might look around.
It might be reading half full because batteries are old and used and don't hold a full charge anymore. Li ion is 3+ V so I'm not sure how you'd get that to work. I've found AA's start out at 1.35-1.6 V and drop to 1 V and then they are dead or something like that. Not sure how to interpret the V of battery you posted or if it'd hurt the flash. What charger and how fast are you charging?
Since lithium ion battery cells have a voltage of around 4.2V (fully charged) to 3V (discharged) with a nominal voltage of 3.6V to 3.7V, the way these types of lithium AA batteries work is that they have an internal voltage regulator that steps down the voltage from the battery cell and outputs a constant 1.5V.
This has its pluses and minuses. On the upside you get a very consistent full power voltage from the battery. This is great for some devices whose performance is voltage dependent, like devices with DC motors, as these will always run at full speed (rather than slowing down as the battery depletes as with alkaline or NiMH cells). Also can work well in some flashlights, delivering consistent brightness while in operation.
The downside is that there is zero useful indication of remaining battery life. From the device perspective, the batteries essentially just go from 1.5V to 0V once the internal cell is depleted and no longer providing current (the battery's internal electronics probably has a cutoff voltage at which this occurs to protect overdischarge of the cell). But in any case, there's no gradual voltage decline that allows the battery life meter in any device to work properly, so the batteries effectively just go straight from 100% power to dead when they run out of juice.
So the only way to really have any idea of how much runtime you have left is if you know the power draw of the device and can calculate how long you have used it for so far. But this only works for devices with a fairly consistent power draw. If the power usage of the device varies, you are pretty much guessing at that point.
Another consequence of the internal electronics in these 1.5V lithium rechargeables, is that these batteries typically require specialized chargers, as they don't behave exactly like traditional lithium ion cells which would typically be charged at around 4.2V. Many of the 1.5V lithium ion rechargeables charge at 5V to 6V instead (hence the built-in Micro USB port on some models).
In terms of overall battery capacity, one thing to note is that many of the 1.5V lithium ion rechargeable manufacturers seem to report the battery capacity in milliwatt-hours (mWh) rather than milliamp-hours (mAh). Which can easily lead one to believe that these 3000 mWh rated AA lithium ion batteries have higher capacity than NiMH or other alternatives. But higher quality NiMH rechargeables, which are 2500 mAh x 1.2V also are rated at about 3000 mWh. So the published capacity of the lithium-ion AA batteries isn't any higher.
And at least from the EBL 1.5V lithium ion AA rechargeables I have tested, the actual capacity is lower than what is advertised. They are really more like 2300 mWh (about 1700 mAh @ 1.5V) which is actually less capacity than the higher quality NiMH rechargeables like the Eneloop Pro AAs which actually achieve their 2500 mAH (or about 3000 mWh) rated capacity in many cases.
This testing was done with a constant power draw of about 600 mW or 400 mA @ 1.5V (which is roughly about a 0.2C discharge rate based on their rated capacity). This yields an overall battery runtime of just under 4 hours. It's possible that under different power draw patterns the batteries would perform slightly differently. For reference, under the same kind of 600 mW power draw the 2500 mAh Eneloop Pro AAs run for closer to 5 hours which is about what you'd expect given their rated capacity.
So to summarize, the takeaways for me were:
- use 1.5V lithium rechargeables in devices that don't turn on or operate at all with lower voltage (1.2V) rechargeable batteries
- use 1.5V lithium rechargeables for devices where you want to run at full power all the time (motors, lights, etc.) and don't care about the device dying without warning when the battery runs out
- use NiMH rechargeable batteries for pretty much everything else...Show more →
This is really excellent information. Thank you for the insight.
p.1 #14 · Anyone use high voltage AA rechargeables?
I had the same issue with my R2 Pro II triggers--they need the higher voltage to deliver accurate indication of remaining charge. Didn't want to use alkaline. But I finally tried two alkalines in one trigger and they lasted a full year. Apparently there is no battery drain except during the 1/200 second it transmits, so they last and last. So I decided alkaline for the triggers and I stayed with my old eneloops(1.2) for other needs...
p.1 #15 · Anyone use high voltage AA rechargeables?
buddy duck wrote:
I had the same issue with my R2 Pro II triggers--they need the higher voltage to deliver accurate indication of remaining charge. Didn't want to use alkaline. But I finally tried two alkalines in one trigger and they lasted a full year. Apparently there is no battery drain except during the 1/200 second it transmits, so they last and last. So I decided alkaline for the triggers and I stayed with my old eneloops(1.2) for other needs...
My eneloops only last a couple weeks in my triggers. No idea why.
At 100% full charge, they read full, but they very quickly fall to 2/3 bars, where they stay for a while, then trickle on down. If I leave them in the triggers, they're dead in a couple weeks.
Maybe the cells are ready to be retired, dunno. Alkalines seem to perform way better, I just hate the idea of buying so many Alkaline cells.
p.1 #16 · Anyone use high voltage AA rechargeables?
deepbluejh wrote:
My eneloops only last a couple weeks in my triggers. No idea why.
At 100% full charge, they read full, but they very quickly fall to 2/3 bars, where they stay for a while, then trickle on down. If I leave them in the triggers, they're dead in a couple weeks.
Maybe the cells are ready to be retired, dunno. Alkalines seem to perform way better, I just hate the idea of buying so many Alkaline cells.
I've been using Eneloops since 2007. As Mike correctly pointed out, they have a very slow discharge rate. If they are discharging in your triggers when not in use, then your triggers are draining them through a circuit that doesn't fully turn off or an internal short. There are a few electronic devices that don't play well with NiMH batteries (my home thermostat is one), but they are rare. They worked perfectly in my Yongnou triggers back when I used them.
I do not work for Eneloop...
p.1 #17 · Anyone use high voltage AA rechargeables?
brad-man wrote:
I've been using Eneloops since 2007. As Mike correctly pointed out, they have a very slow discharge rate. If they are discharging in your triggers when not in use, then your triggers are draining them through a circuit that doesn't fully turn off or an internal short. There are a few electronic devices that don't play well with NiMH batteries (my home thermostat is one), but they are rare. They worked perfectly in my Yongnou triggers back when I used them.
I do not work for Eneloop...
I have some AA Sanyo Eneloops from 2006 that still had decent capacity performance when tested in 2020. That is pretty impressive. This is coming from someone who started with 450/500mAh AA NiCd cells in the 1960s and owned/tested literally thousands of AA cells in the past 50+ years. In the 70s/80s you had to design your own test equipment for the most part. Early NiMH cells around 1991 were useless under load and it took the better part of the 90s for impedance to drop. When capacity increased in the 2000s NiMH self-discharge was still a problem. Eneloop simply changed everything with low impedance, low self-discharge, and crazy longevity.
p.1 #18 · Anyone use high voltage AA rechargeables?
deepbluejh wrote:
I'm tired of my flash triggers always reading half empty, even when the batteries are "full". Plus... my current cells are getting old and tired. Looking to buy new ones and looking for something better.
Also... "no issues" have been a stretch. I've always hated AA batteries (vs lithium ion). Upgrading to higher power cells would be an improvement at least.
I never thought my flashes were right with rechargeables. They always showed a half charge. I thought it was the batteries half charged.
p.1 #19 · Anyone use high voltage AA rechargeables?
I was using Eneloop for the past couple of years, but have recently been ordering Tenergy AA cells from Amazon. They have a rating of 2,800 ma and the Eneloop about 1,200 ma (from memory). When using my speedlites, I always use the extenders. The ones that I have hold 8 more AA cells. I have shot for several hours using 12 of these Tenergy AA cells per light and not had a battery problem. Look at the ma (milli amp - Thousandths of an amp 2,800 = 2.8 amps) rating for the cells that you buy and get the ones with the biggest capacity. Fresh cells and the extender have my speedlites ready for the next flash in about 2 seconds. I run at a slower pace to keep my speedlites from overheating, but they are ready to go again in about 2 seconds when running on the set of 12 fresh Tenergy AA batteries. I have 24 new Tenergy cells due to arrive tomorrow from Amazon. These will be additional spares, fully charged and waiting in case they are needed.
p.1 #20 · Anyone use high voltage AA rechargeables?
I have a number of NiZn batteries that supply 1.6 V. Because I actually have a handful of devices that work with non-rechargeables, but not NiMH rechargeables. These devices (a flash, a toy, a GPS) work great with NiZn rechargeable batteries.
Still you might look around. 