What 12v battery Amperage for field work please?

Morning everybody.
First posting, so please be gentle....
Although only just returning to CB radio. I`m showing a keen interest in going off grid so to speak with maybe a T2LT antenna and some jam sandwiches, oh and obviously my trusty Mckinley.
I don`t want to invest a huge amount in this adventure to start with as I`m not sure if it will take off for me. So, now everyone knows I`m a tight wad what amperage battery could I get away with to start with & how long will the battery people are suggesting last roughly??? Any links would be appreciated too.

Many thanks for your help.
Regards
smileymiley.

Hi Paul,

Amazingly everyone agrees in an amicable way about utilising battery technology......not.

How 'off-grid' are you going?

If in the car to a high spot then you may as well just use the battery that's in the car and save lugging anything else around. If you get into serious high ground DX transmitting for hours on end then start thinking about another battery, maybe a leisure type and invest in a good charger for home. Better that than finishing up some DX for the day then finding out you can't start the car!

When travelling on foot, bicycle, motorcycle or whatever then you'll obviously need to lug around a battery.

If you just want to give it a taster then £15-£20 will buy you a 7aH or more Motorcycle lead acid battery or a typical alarm style AGM from the local DIY outlet. Bit like carrying a brick around with you weight wise.

If you want to give a similar amperage LiFePo4 lithium battery a go expect to pay four to five times more and it'll still feel like you're carrying a brick.

The lithium will last longer than the lead acid as regards charge cycles but when you work out the cost difference it's still quite similar overall. (Four to five times the price for four to five times the number of recharge cycles.)

How long will they last on a charge?

Bit of a piece of string question really - receiving doesn't take much battery life whereas transmitting obviously does and that depends on how much power you're transmitting. Your own personal mileage will vary probably considerably from anyone else. (Especially those that like to 'boost' figures to make for interesting reading. )

You're bound to get many more recommendations and find a plethora of stuff on the internet all ably assisting you into more confusion.


It's all quite exciting to think about operating off-grid to start with but as you delve deeper you may find the novelty wears off. You can spend silly money on battery and recharging technology which will feel awesome with a good DX day and a total waste of cash if you don't get a single contact.


But, there's many that regardless of the contacts they make enjoy the adventure of running off grid. Just look at the SOTA, (Summits On The Air), guys who trek miles across moor and mountain and simply enjoy the whole experience. As for CB radio, driving up a hill to add tens or hundreds of metres to your antenna height is easier than adding scaffold poles to your QTH home base setup! Plus you can get away from all the QRM associated with typical human habitats.

It might just be worth it all to bag that elusive DX.


All the best and have fun,
Victor

Morning Victor.
Many thanks for the expert reply.
I`ve seen in Screwfix a sealed lead acid battery for £25. It`s 7 Amp H , I was given a £50 voucher so was wondering if I could run them in series to give me 14 AH? If it doesn`t pan out that I`m cut out to be Rambo in the field, more like John Inman, then I kind of not wasted too much money. I was thinking of getting a 6m fibreglass flag pole too and whacking the T2LT up on that. Like most, I`m surrounded by idiots, er I meant high noise levels, so I have a place near to me over looking Essex and East London that`s pretty high up. I may pop there early one morning and see what it`s like using my Sirio ML145 mag mount first, just to get a feel for the place.
Regards

just make sure the fiber glass is not carbon fiber as it does things the swr, My high spots i can drive to and there is a very nice wooden poles, and i use 170 amp hour leisure bat and only charge twice i had to buy a good charger and the bat is heavy, i use a sack barrow to shift it i have never run it flat, so thats ok for me 2100 feet asl, and there is another spot i use is 1,950 feet asl i sit in the car, as it can be nasty at that hight and the radio magnum 257 and ssdx5000 low power version, 40w flat out not been out the last two years covid 19 , but this year we will try to get out.

Smilley 
I run 2 12v 9amp ups battery’s in a golf cart bag I can run them parallel or as single units mainly as static mobile but had lugged them about in my bag. I get a good days operating from them 60/40 RX TX. I will look at a better solution to get a few days out of them or as some have already replied a leisure battery I run a 8m fishing pole fibreglass made a drive on plate so easy quick deployment run a T2LT for 1o/11/12. A home made 2m/70cm beam for the other radio.

Just curious if anyone has tried using one of those Lithium jumper packs that go for 50 USD plus or minus? I have a 40 USD one that is supposed to be 13.2 AH.
www amazon com/gp/product/B07S5968FF (add periods)

Be aware that lead acid batteries go bad quickly if you discharge them more that 50% and also lose capacity at high discharge rates - so compared to lithium which can supply their full capacity they only really have 1/2 or less their rated capacity except in an emergency when you don't care if you destroy them.

RoadRanger wrote:

Just curious if anyone has tried using one of those Lithium jumper packs that go for 50 USD plus or minus? I have a 40 USD one that is supposed to be 13.2 AH.

I have one I use occasionally, not the one you highlighted, mine is one from toolstation and is currently on at nearly £90.. prices are going up on everything aren't they!? I have a little adapter that converts the car jumping port to a cigarette lighter sockets and that's what I plug the transceiver into as the other output ports don't give quite enough juice. I've nearly really pushed it, but it happily runs my 6900n for a couple of hours with some battery life still remaining.

I used to have a 95 Ah leisure battery but at 26 kg, it was a bit of a weight.

So I invested in a 100 Ah LiFePo4 battery and have never looked back. Longer life, is easier to charge, holds the charge much longer and only weighs 9 kg.

I also bought an 18 Ah LiFePo4 portable battery for SOTA etc. Weighs about 2 kg and works well (it's for a golf cart and has powerpole connectors) and is quite small.

LiFePo4 has worked so well for me. Yes, a higher cost upfront but for me, the advantages outweigh this upfront higher cost.

Regards,

Paul