| T O P I C R E V I E W |
| i80386 |
Posted - 02/09/2023 : 11:03:16
Hi to all, the original Tenergy 800 mAh battery is now for replacement. The substitutes that I find are with PCB protection - 850 mAh capacity and without protection - 1300 mAh. Which type is suitable and safe to use with device?
[url=https://postimg.cc/8jpZcJSN] [/url] |
| 8 L A T E S T R E P L I E S (Newest First) |
| Damien68 |
Posted - 02/27/2023 : 05:45:27
quote:
Originally posted by ullix
Difference in boards:
On a GMC-500+ the U8 is a 5-legged chip LTH78(?), while U10 LW629(?) might be a MOSFET.
ullix, you are right on 300S the charge controller is U7 and V8 is the MOSFET mounted in "ideal-diode" or "ORing" mode for power supply.
quote:
Originally posted by ullix
To be sure: 2 protections in series are never a problem?
I'm not sure I understand the meaning of your question:
1.first possible meaning
the charge controller regulates the battery charging current, and cuts off recharging when the voltage on the battery reaches 4v2.
the protections in the battery should normally never trip. they are there only to protect the battery and the user from mishandling or failure of the device.
by failure of the device, we speak for example of a semiconductor or a capacitor which short-circuits.
2.second possible meaning
having a protection in the battery plus a second added on the PCB does not seem to be a problem but it is to be checked in particular for the protection against excessive recharging (over 4v2). The simplest in my opinion is to recommend to not use unprotected battery. |
| ullix |
Posted - 02/27/2023 : 04:02:35
Difference in boards:
On a GMC-300E+ as well as on a GMC-300S the U8 chip is 3-legged and a Mosfet A1SHB.
On a GMC-500+ the U8 is a 5-legged chip LTH78(?), while U10 LW629(?) might be a MOSFET.
To be sure: 2 protections in series are never a problem?
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| Damien68 |
Posted - 02/27/2023 : 02:41:10
quote:
Originally posted by ullix
U8 is a simple MOSFET, likely for "load switching" like from USB to battery.
You think this is all there is in the counter for battery protection? Is this also related to the reported problem of frying the counter when a batt is accidentally inserted in reverse?
@ullix, No U8 is the SOT23-5 package (with 5 pins) it's a Li-Po charge controller LTC4054ES5-4.2:
https://www.analog.com/media/en/technical-documentation/data-sheets/405442xf.pdf
the Mosfet close to "U8" print is V10
in the case where protected batteries are used, it is a priori sufficient.
in the case of an unprotected battery use, if there is for example a defaulting capacitor or a defaulting semi-conductor that do a short-circuits (this can happen) this can cause problems. I don't know if there are directives about this in the CE/FC/FCC standard.
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| ullix |
Posted - 02/27/2023 : 01:16:21
U8 is a simple MOSFET, likely for "load switching" like from USB to battery.
You think this is all there is in the counter for battery protection? Is this also related to the reported problem of frying the counter when a batt is accidentally inserted in reverse?
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| Damien68 |
Posted - 02/26/2023 : 02:43:14
quote:
Originally posted by ullix
Questions to the local "electricians":
Since a "protected" Li-Batt does not fit, I would assume that the GMC counter board has that kind of protection included. Can you see it and point it out on a picture?
But if a protected Li-Batt were possible, would two such protections in series not somehow fight against each other, or is such always possible and never an issue?
about protections on LiPo you can read this article:
https://www.fenix-store.com/blog/what-is-the-difference-between-protected-and-unprotected-18650-batteries/
there are one protection already included in the U8 charge controller such as overcharge protection, i thinks thats all.
heating/presure problems occur especially during fast charges, which is not the case here,
the maximum discharge current is "a priori" sufficiently limited and therefore is not a concern here except in the event of hardware damage, in which case it is the PCB tracks that will fuse, also in principle it is better to have additional protection in the battery because the energies involved are quite high.
remains the over-discharge protection, does the counter cut off the power if the battery drops below 2v8? Does it really shut down the whole system reliably? (a microcontroller brown-out reset is not necessarily sufficient).
In conclusion if you use an unprotected battery (I don't recommend it), so if you use unprotected LiPo battery as a precaution you must avoid letting the battery completely discharge in the counter.
NB: the vast majority of LIPo batteries have protections, the rare exceptions are for example for electronic cigarettes because the current used is very high (10-30A) and for this reason there are no easily feasible protections.
in general, at least for the 18650 models that I know better, the protected battery has a bump on the contact (+) and the unprotected battery has a flat contact on the contact (+) (as for the (-)). |
| ullix |
Posted - 02/26/2023 : 01:30:52
Questions to the local "electricians":
Since a "protected" Li-Batt does not fit, I would assume that the GMC counter board has that kind of protection included. Can you see it and point it out on a picture?
But if a protected Li-Batt were possible, would two such protections in series not somehow fight against each other, or is such always possible and never an issue?
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| i80386 |
Posted - 02/25/2023 : 01:31:37
It might be useful for someone: Protected battery does not fit. Its length is 2-3 mm more. Apparently an unprotected battery must be used for this device. Nitecore NL1485 is not a option fo GMC-320 Plus. |
| EmfDev |
Posted - 02/09/2023 : 14:21:33
The 1300 mAh option may provide longer battery life. However, without protection, the battery may be more susceptible to damage if not handled and charged properly, so its important to be mindful of the batterys usage and charging habits to ensure its safety.
I you just install the battery and not take it out often, then the no protection is ok. |
