I've got one of the Kenwood OEM LiPo batteries that I share between a couple of radios and I don't see a big difference compared to the Lithium Ion or NiMH. $20 differences is a big price difference for a battery.
While memory isn't an issue, take a look at how you really use your radio. If you use it heavily and are constantly running the battery down during your shift, then you need a higher capacity battery. If the smaller capacity batteries get you through a shift without dying, then you've got the right one. Spending the extra $20 isn't really getting you anything.
I ordered all our NX-410 radios with the KNB-33L lithium Ion batteries. They are 2000mAh. They get the radio through even a long day without dying. In fact, if the radio isn't used that much, we can get nearly 2 days out of them. Spending extra for higher capacity batteries would be a waste of money, especially when multiplied out by 300+ radios.
The NiMH and LiPo batteries from Kenwood are around 2500mAh, so you only get a bit more. They cost more and they are thicker and heavier.
I used the LiPo battery the last two days and it's noticeably thicker on the belt. I did accidentally leave the radio on all night, and it pretty much lasted 24 hours.
What I've encouraged our users to do, instead, is to have at least one good battery for daily use, and charge it at night. For emergencies, use the KBP-6 AA battery shell as a back up.
We've also had good luck with the Power Products brand of batteries and chargers, if you are ever looking for another brand. They were actually recommend not only by the local Kenwood shop, but also the Kenwood factory rep.
