Hooray! New Solarstorm BC-2 4x18650 battery (2S2P) case for bike lamps

Hi Gray, will you be testing the 6x 18650 case? Seller claim "10μA" parasitic drain this round.

I don’t have a 6x18650 case. Not sure when I’ll get to testing my 2x26650 either.

-Garry

Is there actual charging circuitry in this thing?

Or is it depending on the power supply to do the CC/CV charging ?
(Because in normal bike lights, charge control is done in the battery holder, and I can’t see any circuitry in these holders other than springs…)

wle

Not usually no. Majority of bike lights rely on the wall wart to charge with proper algorithm and cut-off (majority don’t “cut-ff” per-se, but just diminish charge current to where it reaches 0.00v). The holder MIGHT have an over-charge cut-off and over-discharge cut-off.

-Garry

the case specs do mention overdischarge and undervoltage protection..

you said:

"(majority don’t “cut-off” per-se, but just diminish charge current to where it reaches 0.00v)."

but did you mean:

(majority don’t “cut-off” per-se, but are actually simple constant-voltage controllers, controlling current to keep voltage below 8.4V )?

Nope. The voltage can be higher than 8.40v when the charge current reaches 0.00A. I THINK (I’m no expert) that one thing that plays largely into this is the “no load voltage” of the charger. Some really bad bike light chargers put out over 10v no load! The “good” (i.e. acceptable) ones put out around 8.42v to 8.45v. Some are labeled as chargers and are nothing more than a power supply thereby relying on the packs protection pcb to stop the charging process.

See the review I just posted on the ROCKBROS battery pack and included charger. There are timelapse videos showing how the charger is operating.

Also, I should have said that I’d NEVER charge the cells in these boxes! One of the biggest reasons to have these boxes is to charge these cell individually.

HKJ has also published a review on at least one of these types of chargers showing how they just “float out” to extremely minimal charge current.

-Garry

Here is an HKJ review where there was some discussion on the lack of cut-off.

-Garry