radio question/suggestion

Hello to all!

Another question about ‘which one’.

Here is the details: I am trying to communicate from inside a house to a pasture at about a distance of 2500’, flat terrain, there are a couple of tree lines/brushy areas, a hay field, across a two-lane road, and open area.

(I am not even sure this is possible, and I think the ‘from inside the house’ part might really cause difficulty but of course I can always get a 30mile walkie-talkie:rolleyes:)

Any advice/selections is greatly appreciated!

Are you using it for leisure or local business where you prefer not to file paperwork and payment for a license… go MURS.
The RDM2020 and RDM2080 are great radios for what you are doing and will easily give you 2500’ range in those conditions. You can also use a RDV2020 or RDV2080 and have it programmed to MURS frequencies- I’ve done this before.
There are a lot of other radios that will perform just as well too but that is my suggestion. Remember those Motos are business grade radios so they are rated for Mil Spec 810 D-E-F… and will give you years of quality service if cared for. Also standard is a lithium-ion battery (as opposed to the nimh batteries in most GMRS/FRS radios) and plenty of audio accessories.

Let us know which way you go.

Thank you alphacommnj for your reply!

OK, after I did more research: Wow! Those RDM radios are very nice - I like them.
But, wheeeew, that is $400 for a set.
As for the batteries in those radios (lithium-ion) how many years will those give me service? Do they need to be constantly charged, or can they remain unused for long periods and then charged up?

thanks again!


The Li-Ion batteries are a vast improvement over Ni-Cad and NiMH batteries commonly found on older two-way radios. The life span is excellent (rated 12-14hrs per charge) on the RDV2020/RDM2020 series and will not suffer from the “memory effect”. Traditionally batteries needed to be DIScharged completely before recharging them…however with the lithium ion batteries you can throw them on the charger whenever you like and simply grab the radio when you need it.

I generally mark new batteries with a sticker to replace 2+ years from the date purchased. This is when you may notice a decrease in life expectancy. If you don’t abuse the radio, the batteries could last 5-10yrs, but they will significantly reduce down to perhaps 1hr by this time. A battery lifespan cannot be measured by time but rather how many charge cycles/how often the battery is used. Using the battery less often or letting it sit idle for long periods of time will not adversely affect the life of the battery.

The initial cost is more expensive than a consumer radio but look at it this way: I have business clients still clinging onto radios from 5-10 yrs ago, trying to keep them alive. Granted the batteries are useless and the radios look like hell, but they work! Take that $400 for the Motorolas and divide it by 10yrs… $40/yr is your total cost of ownership for the RDM/RDV Motorola business grade radios.
Similarly, consumer radios have an expected lifespan too. For me, its been 1yr+ before something breaks, they are just not manufactured to last long that is why they are priced so cheap. The consumer radios are roughly $60 a pair. Replace the set every year and the total cost of ownership is $60/yr. That’s more than the commercial set!

I should disclaim in no way am I guaranteeing the lifespan of a radio, just providing my experience and suggestion. :wink:

Well, really, Lithium-Ion batteries DO die over time. If you were to buy one, put it in a freezer, and store it for 5 years… when you use it it will be dead. No matter how many times you do or do not use a li-ion, the battery will slowly lose service life from the day it was manufactured.

Once manufactured, a li-ion begins to decompose. Nothing will stop this.
I have found, no matter what batteries I have used, 2 years is the max… cellphone, radio, computer, camcorder.

Li-ions do like to be charged as often as possible. They HATE being totally discharged. Kind of like a car battery… once it runs dead, it is damaged, causing lower service life.

You’re right jwilkers, a li-ion battery is (inevitably) subject to a limited life-span depending on usage, however the strong points of lithium ion are it’s cold weather performance and ability to hold up over time vs. Ni-cad or NIMh.

When it comes to performance, there is a reason most electronics (including the upper tier two-way radios) offer a lithium-ion battery standard or as an upgrade. No battery is perfect, and a large factor in the life of a battery is the quality of manufacturing, so you will see cheaper li-ion batteries degrade faster (in phones, camcorders, iPads, etc.) than in mission critical devices (such as two-way radios). I know for a fact Motorola puts their batteries through some of the toughest extremes of temperature, shock, vibration, etc to be sure they will perform is the worst of conditions.

That being said, li-ion batteries do have their weaknesses:

  1. Being fully discharged (like jwilkers mentioned, if a li-ion battery goes low enough, it will never recover to 100%)
  2. Limited number of charge cycles. After X amount of discharge/charge cycles, a lithium ion will no longer be usable for more than a few min, hrs (depending on original rating)

So how about the positives:

  1. Cold Weather Performance. Lithium-ion batteries do great in cold weather! In fact, if you leave a Li-ion battery in the freezer for 5yrs it won’t be completely dead! Sure, it loses some expected capacity, but try that with alkaline batteries…they wouldn’t work after being in a freezer for 1 day. See the chart on the link below: a li-ion charged to 100% capacity will lose 6% life every year when in 32F temperature. So in your example jwilkers, a li-ion should only lose 30% of it’s capacity when you take it out of the freezer in 5yrs. If you read more about the lithium ion batteries you can lower the loss by storing it at 40% charge instead of full.
    On the contrary, li-ion does not do good in heat and can explode if it gets too hot.
  2. Li-ion batteries generally provide longer run-time, do not need to be fully discharged before recharging (no memory effect like NiCad), and give you more useful life out of each charge (device will not slowly dim or lose power. This can be a negative for some people as you won’t know your battery is dead until suddenly it stops working).

With that said, breakerbreaker, you should be good to keep your radios sitting on a shelf until you need them. No doubt the batteries will not last forever, but the li-ion battery will provide you with the best overall performance in a radio.

Wow. Battery tech has come a long way. This is some good info here, thank you for explaining!

OK, 1 last question (thanks for your help!) : What about power outages? Thunderstorms should only produce hours long outages but what about ice storms? Do people with comm gear rely on generators? Any way to use regular batteries in these radios?

we should re-name this thread: “what type of battery is best and why” :stuck_out_tongue:

In response to the power-outage question, yes, most businesses/emergency services/organizations that rely on comm gear do use generators or battery backup systems, to either power infrastructure equipment like repeaters or charge portable equipment such as handheld two-way radios.

It’s ironic you ask about the loss of power, as we speak a large majority of NJ (including myself) have no power. Similar to the hurricane in the northeast a few months ago, we have been without power since Saturday. The radios I recommended are capable of using conventional alkaline AA batteries in the case of emergency power. Motorola makes an “alkaline frame” kit since you can’t directly put batteries into the radio. It looks similar to the li-ion rechargeable battery but holds 5 AA batteries and will last 20+ hours. You can contact me for more details about the AA battery pack or to order it.

The alkaline frame kit you are referring to is the Motorola RDX Series AA Battery Frame (RLN6306). We do have it in stock and it can be purchased directly from our web site.


OK. These radios are making much more sense now. That is great info about being able to use regular batts!

Now, I will do some thinking about the $$$. (Maybe a Christmas present to myself!)

Go for it! You won’t be disappointed.