Ra Twisty and Unprotected Cells?

[Chrontius]

thinking about taking the plunge cheaply. I know that unprotected cells are normally Bad News(tm) unless you're anal about them, or have a circuit to protect them. Fortunately, Ra built a circuit to protect them.

I'm thinking about a Nano Charger and 1-2 unprotected cells, maybe IMRs for forwards compatibility. (G2Z with P91?)

Are LiFePO4 compatible with Ra's firmware? Anybody sell them/chargers yet?

What are the merits of unprotected cells in this configuration? Risks not compensated for by the light itself?

 

[tygger]

Been using Tenergy LiFePOs from BatteryJunction in my Ra Clicky for a couple of months now. So far they're great, with better than expected performance. A lot less capacity than primaries of course but thats why I carry spares. And the Tenergy charger weighs next to nothing so its easy to take along.

 

[MWClint]

IMO, i'd never try to save a couple bucks and buy standard LiCo unprotected cells if the plan is to use those cheap bay chargers.

while the light itself may have protection built in, the charger does not.

a failed charger is a nice way to go poof.

on the other hand, if you are using a hobby charger $$$, then go ahead and
safely handle unprotected cells. as there are multiple backup safegaurds on these chargers.
-voltage/mah readout on lcd so you can easily monitor the charge.
-temp probes that cut off charging if the cell heats up.
-manual timer overrides.
etc


not saying those cheap bay chargers are in any way gonna burn down your
house, but why take the chance. Buy protected cells if you are going to use
a cheap charger. consider the extra $4/cell as insurance. especially if it's
your first foray into lithium.

 

[Oddjob]

IMO, i'd never try to save a couple bucks and buy standard LiCo unprotected cells if the plan is to use those cheap bay chargers.

while the light itself may have protection built in, the charger does not.

a failed charger is a nice way to go poof.

on the other hand, if you are using a hobby charger $$$, then go ahead and
safely handle unprotected cells. as there are multiple backup safegaurds on these chargers.
-voltage/mah readout on lcd so you can easily monitor the charge.
-temp probes that cut off charging if the cell heats up.
-manual timer overrides.
etc


not saying those cheap bay chargers are in any way gonna burn down your
house, but why take the chance. Buy protected cells if you are going to use
a cheap charger. consider the extra $4/cell as insurance. especially if it's
your first foray into lithium.

I have to agree from a safety standpoint. The money you would save is not much weighed against the possible dangers. I have on occasion forgotten that I was charging some cells but fortunately my charger stops charging before 4.2 volts.