Pocketable Fuel Gauges: pictures and howto [serious]

[SternWake]

The 5.5 x 2.1/2.5 inline meter was plugged into my EVE35V 7s2p portacharger’s charge port, while the cccv booster within was charging my Tenpower50XG 10s2p at 8 amps initially. I have to lower the booster output in 3 stages to prevent Eve battery from overheating.

A different meter claimed the cccv booster delivered 3.694 amp hours and 152 watt hours into 10s2p 50XG

I was watching the 5.5 meter when eve voltage fell to 18.64v (2.66vpc) and bms cut power.

Eve 35v 7s2p rebounded to 21.1v ~ 90minutes later.

I used 5.5 meter inline when recharging it at 1.32 amps.

eve 35v 7s2p = 7.0 amp hours

3.65v nominal voltage x 3.5 amp hours x 14 cells = 178.85 watt hours

177.003 wh to take it from 3.01 volts per P group to 4.20v, seems about right. I think.

I like this little 5.5 x 2.1/2.5 meter. I wish it had a 2.5mm pin on its receptacle though, and a 10 amp continuous rating would be nice, too. I don’t know how many 12S and higher systems use a 5.5x2.5 charge port, but this little meter is limited to 50vDC

[sevenfloorsdown]

@SternWake

I just bought one of these on Aliexpress but the female port isn’t working. I could probably fix it but I talked to the vendor and they gave me refund and didn’t have to return it. The male port works fine and it’s only 9 Australian pesos.

[SternWake]

Apologies if the following is insultingly obvious.

The female port has a 2.1 pin, so if your charge source barrel is a 2.5 only, that does not have the opposing spring loaded clasper which can grab either 2.1 or 2.5 pin, no + contact is made.

Here is that universal design.

I stripped the plastic molding from some random device. I think it was from a power supply for a wifi router.

[sevenfloorsdown]

Yeah, I just realized that last night when I played with it on a whim with my other stuff but they already processed the refund.

I poked it with different plugs and realized the barrel length. Most of my stuff is DIY 10 mm barrels but I inadvertently used a shorter barrel but still 2.5 mm.

I got it to work by bending the inner pin on the female side a bit.