A few weeks ago I asked about a battery charger that could be wired to a 12 V battery that would charge smaller AA, AAA, C and D batteries. The one below was recommended, and I ordered that from Amazon.

http://www.amazon.com/Tenergy-Advanced-Universal-Charger-TN190-4/dp/B006OSQALU/ref=pd_cp_e_1

This charger makes a really high-pitched sound, and I noticed a number of other users had commented about it. I think it would drive me nuts in the van, and it seems to make the sound even if batteries are not charging. So, I just sent it back this morning, and now looking for an alternative.

This one: http://www.amazon.com/gp/product/B008467K1E/ref=ox_sc_act_title_2ie=UTF8&psc=1&smid=ATVPDKIKX0DER
looks promising, but I'm not sure it could be hooked up directly to a car battery. There's no mention, so I'm thinking not.

I'm open to suggestions at this point, but I'm steering clear of the Tenergy brand due to the noise, not to mention the door would not open without prying it, pretty cheaply made overall. I do want a unit that can be wired directly in the mains without the use of an inverter.

Troy