Thanks to all.

It looks like NiMH batteries are out of the question for me. I have a
10 Ah LiFePO4 drop-in replacement as my main battery and am very happy
with its performance. I'm looking for LiFePO4 cells (and BMS) for
protection that can fit in my tail battery box. The dimensions of the
drop-in box a

Length = 58 cm
Width = 3.5 cm
Height = 6.5 cm

No luck so far, but I'm continuing the search. I could also build up a
pack for a separate box which I've installed behind the seat back. Its
dimensions a

Length = 36 cm
Width = 4.8 cm
Height = 10.8 cm

Any suggestions would be most welcome. I've been searching the net, but
nothing yet satisfies my specific needs.

Dan

On 2/26/2015 8:16 AM, Pierre Vav wrote:
Hi,

I have a pack of 11 9ah Nimh 1,2 v as a backup battery in the tail of my Lak17.
They have the same format as alkaline D cells.
I use a RC charger that automatically detects the right number of elements.
At end of charge, voltage is arount 16,2 volts, but drops quickly to under 16. Also cable length drops voltage to something usable by instruments (15v).

As it is a backup battery, I use it after the main 9ah pb is lowered down, so voltage is ok.

I never had any problems with these batteries. But they are old now, and i plan to replace them with lifepo4.
also nimh auto discharge force me to derig the tail very often. With Lifepo4, If I do not use the backup, no need to derig.



--
Dan Marotta