I plugged in my booster with 8 AA batteries when the internal battery dropped below 2.4volts. The system then charged up to 2.77volts, however it has stayed at that level continuously for three days. This suggests the booster is permanently powering the Tempest and depleting my external batteries. I didn’t think it was supposed to do this. Does my booster have a fault?
IIRC, it is the Tempest which determines when the booster charges but maybe the booster isn’t notifying the Tempest it is on battery power rather than external power. The firmware on your Tempest is v165 which has the smarts to know about battery vs. external power.
Maybe @eric can have a look behind the scenes at what may be the issue.
The Tempest is on FW165 so that is good. From what I see you have taken the bosster out.
Try again but reboot the Tempest before via the switch underneath and let it boot (wait 1 minute) once that done, re attach the wafer and the rest of the booster.
Let me know when it is back linked and I’ll have another look.
Thanks Eric. I haven’t taken the booster out. It’s still connected and the Tempest is still showing 2.77v. It’s a little difficult to get to, so I’ll need to wait for daylight tomorrow. I’ll get back to you after I’ve reset it.
I had the same problem. Eventually we replaced both the tempest and the booster. As it turned out… it was the booster causing the problem.
When I was field testing, I had to manually charge a Tempest to get it running again. Since this was done with just a power supply, no logic was involved. I wonder if the Tempest not able to communicate with the booster is why some Tempests stay fully charged when the booster is on batteries.
Hi Eric. The Tempest is now reset, and the booster is connected.
Just had a look, you have plenty of sun and the Tempest charges with that though it does not see the booster. It did in the past so something in all the linking must have gone wrong. Or the batteries are depleted (or maybe just one causing the full set to fail ?? Measured with a meter ?)
I think the readings are misleading. There’s been no significant sun on the Tempest today (maximum solar radiation was 142 w/m2 for a short period). I think the external batteries have taken the voltage back up to 2.77. It’s been dark for an hour or so, but that voltage remains constant. There must be a communication fault between the two devices.
My Tempest continues to draw its power all the time from the batteries in the booster. There must be a fault in the communication between the devices. My booster is still under warranty; how do I arrange for a replacement unit?
Open a support ticket with the link in the menu above. Include a link to this thread so you don’t have to repeat everything.
Thanks David. I’ve done that.
I have exactly the same problem. I tried it yesterday with the solution above. About 3 hours the Tempest has discharged up to 2.68V, then it has started to charge it again, since yesterday evening it is again at 2.77V that can not be the point of the thing.
I have 8 Duracell lithium batteries in the Powerbooster, if there is any point in removing any? I am quite at a loss. The Tempest is a replacement device and about 1 week old.
One possibility would be that I disconnect the booster from the Tempest when it is fully charged, but actually that’s not the point behind it.
I’m just a bit worried that it doesn’t do the battery any good to always be fully charged.
Thank you for your help.
Hi, has anything improved for you now? I have exactly the same problem.
Hi Arnold. They supplied a replacement power booster, but that behaved in exactly the same way. So they are now supplying a replacement Tempest. That hasn’t arrived yet (presumably held up by Christmas post), but I’ll let you know whether that makes any difference idc.
Ok, I have my brand new exchange Tempest for exactly 3 days, And it doesn’t seem to work with it. I keep my fingers crossed that it works for you. But I think there must be a fundamental problem, I think something about the software.
Hi Arnold. My new Tempest arrived eventually and I installed it a week ago. I think it’s working properly with the booster. I charged it fully using a wall socket before installation. Since then the voltage has dropped steadily, but now seems to have stabilised at 2.56volts. This is a bit higher than I expected; I thought the booster wouldn’t cut in till about 2.45volts, but it’s certainly better behaved than previously. Keith
The middle portion of the charge curve for LTO cells is relatively flat compared to other chemistries like lead-acid cells. For example, the amount of energy between 2.8V and 2.6V is less than between 2.5V and 2.4V.
[image from https://www.researchgate.net/figure/The-OCV-SOC-characteristic-of-the-LTO-based-battery-measured-at-T-25-C_fig3_324117029]
For this reason, after the battery voltage drops to around 2.55V, the voltage drop is significantly less dramatic for the same energy use.
That’s interesting: a surprisingly sharp bend in the voltage vs energy curve!
Yes, if you zoom out on the battery graph of your station you can see the effects of this property of LTO cells.