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Posted: Mon Oct 06, 2008 10:41 pm
by qdos
NickJ wrote:Hi

The main problem with PV as a charge source for batteries of any kind is that although the output voltage (open circuit) remains fairly constant above a certain light level it is temperature dependant (higher module temp lower voltage) and the current varies all over the shop in proportion (ish) to light level. With most PV systems being static lead acid is preferred as it is quite "tolerent" of varying charge at constant voltage, especially flooded cells, but these are pretty useless for your project. A decent BMS is obvious but as it will be very hard to get constant current at any point and at times the charge may fall to near zero it is a very different kettle of fish to a "normal" charge. Im not a BMS expert but one though is that if the PV was connected to a lead acid battery of appropriate size and voltage in a static charging point at home then it could provide a constant current/voltage charge to balance the pack and recover on the solar.

Just a thought, may not be practical.

This may be of interest to folk I had heard that PVs were a good way to recondition dodgy batteries precisely because of their variable voltage mentioned above.

Posted: Tue Oct 07, 2008 1:11 pm
by MalcolmB
Just stumbled across this solar charger while looking for something else and thought it might be relevant: ... 27251.html

Posted: Thu Oct 09, 2008 10:25 pm
by Nigel P.A. Smith
These are solar batteries on Ebay but are they any good for EV's?

324w Solar Wind Turbine 12v Batteries VR AGM Deep Cycle
Item number: 200259618329

Must get a new set soon myself! Anything better than Trojan T105 or T6220
for the same ish price?

Thanks Nigel

Electric Rover

Posted: Tue Oct 14, 2008 1:09 pm
by Nigel P.A. Smith
Or are these any good, also ebay at £25 each but no date for age and 105/140Ah.

"6 volt deep cycle batteries ( proper ones)
for solar or wind generators Item number: 280275827104"

A salesman said the Trojan T6220 (6volt 220Ah) is the same as the
T105 (6volt 225Ah) only 5Ah less but a much better price, but I think
more amps are needed for my heavy Rover?

Any words of wisdom before I get a new set
of 12 batteries and a new charger!

Tried the Duo Regen pulse treatment but these ones were to old.

Thanks Nigel

Electric Rover
Maybe slow uphills, but not fuming