Hema Battery LiPO replacement


I bought

and used it to replace the battery in the Hema HN7. It ran the unit correctly when connected but didn’t seem to recharge at all. So it is def dead now. I was going to buy another one or even get the LiPO charger but what’s the point if the next one goes into the HEMA and doesn’t charge either

For context the HEMA does operate on the USB when connected and doesn’t seem to need to battery connection to operate, just to run when it’s not plugged in.

I’m not sure where to start in terms of diagnosing this issue. Is it the battery not taking charge or the HEMA not sending it to the battery.

All the wires seem to be properly connected.

I’ll take any ideas and suggestions at this point.


(Yes the display screen is disconnected here - does like to do that on opening - easy enough to reconnect) and yes I have removed the dead battery as well

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Hi Karen,

That’s definitely the most popular battery for HEMA repairs. Do you have a multimeter to test the voltage of the battery? If not, maybe ask a friend for one?

Failing that, the cost of a battery / charger / multimeter are all about the same.


Thanks Graham

I guess the issue for me is why is the battery not recharging? - where do I check the board or how can I check that?


Hi Karen
A bit difficult to do remotely. All very well measuring voltages but that won’t mean much without knowing under what conditions the measurements are made. Just as important are the currents, not only the value in mA or A but the direction of such current. That is a bit more tricky and awkward.
Some sort of ACCURATE connection diagram showing battery, charging system and USB connections would be useful.
Cheers Bob

Hi Bob

thanks for the response.

its not that helpful for me, unfortunately.
the HEMA is a proprietary product and I’m pretty sure they wouldn’t release the circuit diagram etc.

I’ve bought a new battery and a lipo charger now.

what I really would like though is the plastic connector that fits the core battery charger for the hema wires. :slight_smile: I would rather not have to solder.

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