We have two Emlid Reach RS2 / RS2+ systems that have been deployed multiple times without issues with the battery but after sitting for a few months without use, we’re running into an issue with the batteries not being able to hold a charge. They were used a handful of times for ~4 hours at a time in high altitude regions of Alaska (>8,000ft above sea level) in temperatures ranging from +5C to -20C. They held a charge fairly consistently throughout those field campaigns and were stored in a dry, warm place when not being used. They were last used in August 2023 and have been in dry, warm storage since. We attempted to test them this past week to make sure they were working effectively, only to realize the batteries died after ~20 minutes of use in temperatures around 0C. All of the units were fully charged for 8+ hours prior to testing this past week.
We hope to use these Emlids in Alaska again in the coming weeks but are skeptical because of this battery issue. We need the batteries to last 2+ hours in temperatures ranging from +5C to -10C.
We are curious to know if anyone else has run into a similar issue with the batteries not holding a charge or if anyone knows if the exposure to such temperatures may have fried the battery? Can the batteries be replaced or should we look at purchasing new units?
Thanks for your response! I apologize for the funky wording, they indicated low battery but did not actually die or power off while we were using them. We turned them off once we realized their batteries were low.
Let charge overnight for a good while with proper cables etc. Try again. Apparently this type of battery technology needs to always be on a trickle charge even if not used.
Have a backup USB battery pack for each just in case. Those are a dime a dozen.
Charging is best done at room temperature. If too cold it may not accept the charge, or it could be slow or only get a partial charge.
*Room temperature means the devices have been in the room long enough to be at room-temperature. Then you can start the clock on charge-time.
But @E38_Survey_Solutions has probably hit the nail on the head. Batt indicator can get out of sync and the units may have been able to run for a whole day.
So only rely on the battery indicator if you have been using the units recently, or have you have just put them through a discharge-to-power-off/then-fully-charge cycle.
Also, IMO, there is zero harm done to the battery if you run your Reach units until they self-power-off. However, for battery longevity, the important thing is to charge Reach’s battery back up fairly soon and not to leave it sitting in a discharged state for days/weeks/months.
We’ve seen this issue before and it’s usually a battery indication issue rather than a fault with the battery itself. If you let the receiver run until it dies (should take quite a while) the battery indicator will reset, and your next charge should indicate accurately.
Probably, your issue is connected only to the battery indication, as Pat also mentioned. Please make sure that the unit is on the latest firmware, then try to recalibrate the receiver and check if it helps:
Leave the unit discharging until it shuts down completely.
Put the device on charging and wait until it is fully charged.
If you still face the issue, please generate a full system report and send it to support@emlid.com. We can check what’s going on with the battery.
