Adafruit Powerboost not working

I have an Adafruit Powerboost 1000, and a 3.7v 2000mah 7.4wh lipo

When I have the battery plugged into the power boost, nothing happens, no power, no leds.

I know the battery has a charge because unplugging it and reading it with a multimeter shows 3.8v

Strangely enough, if I plug the battery into the power boost and try to read the voltage from the back of the port the power boost is connected to, there is no power, even though the place I am reading the power from should be directly connected to the battery terminals.

When the power boost is plugged into USB, the Chrg and PWR LEDs turn on, and it supplies around 5v power to the output. The low led does not turn on.

Reading the same back of the port that previously mysteriously had no power now have about 4v on them, and I know that the battery is properly connected to that port because if I now disconnect the battery the CHRG led turns off, and the PWR led stays lit.

I have tried to charge the battery with the power boost but the voltage of the battery does not go up.

Could it be that I don't have the right battery? or that I have a broken Powerboost?

Even a dead battery will show its rated voltage when measuring with a high-impedance DVM and no load on the battery.

What is the battery voltage when it's connected to the power boost?

When connected, There is no power.

Do you have the 1000 or the 1000C?

3.8V with no real load is nowhere near fully charged for a Lipo. It should read around 4.2V. So I'd start by charging the battery. If it still won't hold its voltage then you need a different battery.

Steve

The product description says Adafruit PowerBoost 1000 Charger - Rechargeable 5V Lipo USB Boost @ 1A - 1000C

It is standard procedure to measure battery voltage under load, normal load is best or at least a 1 mA load to "bleed-off" the collected charge waiting at the terminals. Using only a high impedance meter can fool you.

I think we need a schematic or drawing of how you have everything connected.
(No pretty fritzing pictures, please. Fritzing pictures are not schematics)
.

What place are you reading from? From the schematic, it doesn't look like the battery is connected to the output port. Also, it looks like there's an On/Off switch. Is it On?