BlueRobotics battery and charger

Blue Robotics Products
1

I have a new BlueRobotics branded 4S6P 18Ah pack and the lithium battery charger. The battery will not charge in “balance charge” mode set to LiPo with a 5A rate. It gives a “low voltage” error message.

I can charge it in regular charge mode, but I’d rather not. Do I have a bad battery, a bad charger, or am I doing something wrong?

1 Like
2

Hi @franz,

Have you used this battery before, or is it new out of the box? What does the charger say the battery voltage is when you plug it in? You can also check the individual cell voltages by pressing the right arrow (+) on that screen.

-Adam

3

Isn’t the BR battery pack Li-Ion? If so, this has a different nominal voltage to LiPo which may be causing an issue. I’m not familiar with that charger, but if it’s based on the 680AC firmware (or similar) scroll across till you see “User Set Program”, hit start, battery type and voltage type should come up, then hit start, then scroll through the voltage types till you get to Li-Ion…select that and try

4

Hi @spotxuv,

That’s actually not true. Our batteries are Li-ion, but they should be charged in Lipo mode. The reason for this is that they consist of modern lithium cobalt oxide cells that have the same maximum voltage as modern Lipo cells, 4.20 V. There is no difference charging our batteries versus a normal Lipo. Li-ion charge modes on most chargers are geared toward older Li-ion cell chemistries, which had a maximum voltage of only 4.10 V. Charging our battery in Li-ion mode wont hurt anything, it just won’t give a full charge.

Franz is charging our battery correctly as far as I can tell.

-Adam

3 Likes
5

ok, interesting, thanks for the info @adam!

1 Like
6

My mistake in plugging things in…I thought balance charging was done only via the balance plug rather than through the XT connector at the same time. There is no problem with battery or charger.

7

Hi @franz,

Glad to see you figured this out! For future readers, both the XT90 discharge plug and JST-XH balance plug must be plugged into our charger to balance charge the battery. The current into the battery flows through the XT90, and the small balance wires are used to selectively discharge the cells throughout the charge process to equalize the voltages.

-Adam