Solar charging times

[rubin]

1. what are the full charging times that one could expect (at perfect conditions) of a battery like the Lithium Iron Battery pack with BMS (24V/16AH) using the portable solar panels (24V/80W) ?

2. does anyone have any experience using this setup (Lithium Battery pack + solar panels charger) at the BurningMan ??

thanks in advance,
 Rubin

[MonkeyMagic]

@~3A output

4-6 hours I'm tipping as it would be similiar to the AC charger.
Cheers

[e-lmer]

Lithium batteries can be charged much faster,
but the internally generated heat shortens the life of
the battery.

A good rule of thumb for small packs is that the mAH
rating of the battery is the maximum current you can
possibly charge at.

So a 20AH battery could theoretically be charged
at 20A and take an hour to charge.

To do that you would need to dissipate all that heat
at the same time so it is not practical.

My GM 20AH 36V battery pack came with a 2A charger, so for
my battery it takes 20AH/2A=10H.

That assumes it is completely down to the
cutoff voltage, which shortens the life of the pack too.

BTW, the most important thing is to not leave your bike
turned on with the LI batteries for extended periods.
If you drain the cells below the cutoff voltage it damages them.

[Leslie]

I can charge 36v 12ah pack on 3X 1.2 amp standard panels in about 6 hours.  Unless I get the bike out in the early in morning for a full day charge the pack does not overcharge but tests full charged on a standard wall charger.  

I get about 250 watts which seems to be what my 12ah pack likes to do.  Inever fully discharge to 11.75v  per SLA.  The voltage sag in 12ah SLA and LVC wont allow it.

The max volts I get seems to behave like a trickle charge with a charge started after 10am, these days I may only get to standby voltages on my SLA's, but again the pack always tests at full capacity and rides the distabnce I need..

I am almost up to connecting these panels to a trailer so I can ride around with them as I do my shopping.

[Leslie]

80 watt at 24v  should do 3.3 amps and should charge a 16ah battery just fine.

Your pack should need about 400 watts to charge from flat and in 5 hours a 3.3 amp 24v panel will charge 16.6ah with optimum conditions.

At 24v

3.3 amps X 5 hours = 16.5 ah