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| Switching from Nicad battery to Lipo: Am I doing this right? |
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| Jwillis:
What is the model of the old Yaesu UHF transceiver.Without knowing the actual power factory rated consumption of your unit its difficult to know whether its a battery problem or a transceiver problem.On any transceiver TX will consume much much more power .A newer Yaesu FT-25R will consume 1.5 A at 7.5 volts on Tx where as Rx will consume 200mA and only 100mA on standby. Did you test the unit without the battery to determine the consumption at standby ,Rx and Tx .Rx may be difficult unless you have signal traffic on a second transmitter on hand. If your transceiver if dropping the battery that far down so quickly I would say theirs a problem with the unit its self. OR Some LiPo packs have over current protection built in .Meaning they will shut down if the current draw is to much.Its there to prevent over heating of the battery pack during a possible short . Older NiCads and NiMh packs don't have over current protection .If your transceiver is pulling more current then what the LiPo pack is rated for it won't work. What is the charge controller circuit configuration in relation to the battery and transceiver.A simple drawing will do.Depending on how your charger is wired you could be over working the circuit and its shutting down. You can test with any 12 volt supply.A lead acid battery will do.But find out what the rated factory current consumption At TX for your Yaesu first. Put a fuse rated for or less than that current consumption in series from the battery before your amp meter. Its the simplest means to control current without calculating a suitable high Watt resister . Standby shouldn't consume much.Rx a little more and short burst of TX will consume much more. Direct battery to your unit will turn it into a toaster if theirs a problem with the unit itself so use a fuse to limit current. I work on a lot of mobiles at work and a lot of them come in with the back ends burned out.This is a because the antennas get broken off and are continued to be used.Then they get turned in for repair only because they start to burn out fuses continuously.Not to say this is your problem I'm just venting. More information on you transceiver would be nice.You should be able to find a copy of the operators manual online very easily. |
| Nohippychicks:
--- Quote from: Jwillis on July 29, 2018, 10:20:02 pm ---What is the model of the old Yaesu UHF transceiver. --- End quote --- This is an FTC-1143. If you can find a manual, please feel free to link it here. The best I can find is "How can I program this radio," type threads in various forums. I can't transmit with it at all, as I can't get it to reliably turn on, so I haven't programed even a single frq in. Even NOAA hasn't been tuned in on this handset. Since you work on these things, maybe you have more information, though! When I key PTT, I get "ERROR," in the display. Do you know if that's what it should display with no frq to transmit on? It seems reasonable. When you say that these get burned out, what should I look for to check for that? I , personally, have never tried to transmit without the antenna installed, but the history isn't known. I've also not opened the radio, figuring that if it turned on and had a display that would be a good enough function check for the time being. |
| TERRA Operative:
I would start by replacing that charge/protection module with a charge only version, your battery already has a protection circuit in place. The protection circuit in the charge/protection module maaayyy be causing the issue as it isn't designed for your battery in particular. |
| Jwillis:
I sent a request direct to Yaesu for specifications but will be a few days for a reply if at all.Sometimes I get lucky when I ask nicely. The error your getting is most likely not enough amps are being supplied.Our mobiles will do the same thing.That tiny buck boost will deliver 12 volts but the available current will drop off significantly.An older model like yours will likely draw more current than a newer model.So I wouldn't doubt if it goes as high as 2 amps or even 3 amps on Tx (PTT). My personal mobile will draw 20 amps on a transmit .Just popping in a FET to bypass current probably won't work because your dealing with 2 separate voltages.12 volts at the gate and 3.7 at the source.3 of your LiPo packs wired in series might not even be enough.But its worth a try since theirs 4 amps available at 11.1 volts in series. Hand held s were not designed to be used to be in constant Tx. Even the best ones will only function for a short time. |
| kjr18:
--- Quote from: KL27x on July 29, 2018, 09:49:33 pm --- I had to do a doubletake; I would be happy with those numbers on my own boost circuit. So with my calculator, I come up with 86.5% :-// --- End quote --- You might be right. I should've used a dmm instead relying on my load led display. :palm: |
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