Battery power for portable DATV

[M0YDH]

Hello all

With 11 June contest day looming, my beginner's question is what do you recommend for a battery setup for operating out the back of my estate car?
All my portable amateur radio to date has been the real thing - mountain top portable and carried on my back to the summit. Batteries are LiPo for lightness. 4Ah is a big battery in this game.

It looks like the draw on transmit will be less than 8A. I've 12V services for the station and FT857D and a Lenovo mini PC computer that's either mains or 19V.

A leisure battery, some class of battery monitor and a pure sine wave inverter seem to be of interest. I don't know what to get so look forward to your advice.

Best regards
David M0YDH

[G8DKC]

Hi David,

If you are going to do some serious portable work....

My list would be one maybe two 125Ah AGM batteries, 3 or 4 years guarantee, cost a bit more, but anything else lasts about a year.

Battery may seem large but you don't want to take home one that's gone below 12v and won't come back up to full charge.

A 3 or 4 stage charger at home, a modest one say 25Amps if there is a week or so between trips, to bring the batteries back up.

I would keep batteries float charging between trips if you can after charging.

Make sure you get a pure sine wave inverter, again one to run the mains bits and pieces, soldering iron etc. say 250w - 500w 12v.

A larger inverter may seem silly but some kit, Pcs etc. will draw more power on start up, modern inverters economic on standby.

E.g. a RV / Boat 60w mains fridge motor needs a 800w inverter for a second or so to start. Only as an example

Last idea is a split charge kit with battery / batteries on frame bolted in the back of car, won't charge till car started,

they will still benefit from a good 3 or 4 stage charge from time to time as car alternator usually a little basic.

That's my list of kit that I've used, everyone has their own story

Battery info... https://www.victronenergy.com/upload/do ... ies-EN.pdf

Peter

[M0YDH]

Thank you Peter for the full reply. I ordered a pair of AGM 100Ah 12V batteries for £190. Still a Crikey moment!

https://advancedbatterysupplies.co.uk/p ... 100ah-12v/

Our club chairman sold me a new battery charger of the intelligent microprocessor controlled variety for £20 so I should be able to look after them.
I guess I make a terminal kit and monitoring box up next.
The last inverters in Maplin were 24V ones today. Pity - they were £20 each.

Cheers
David M0YDH

[G8DKC]

Hi David,

Ok on AGM Batteries and outlay

You may have thought of it, I didn't on my reply, that 19v could have come from one of those " Up converters".

So less immediate need for inverter, just a thought.

EBay item number: 263218054551 etc. etc..

Regards

Peter

[M0YDH]

Thank you Peter. I ordered one of those upconverters straightaway. Also the bits for DC distribution board with crowbar and reverse polarity protection by AD5X and M0MTJ. See their websites. I think I'll add a 11.75V cut out using a Zener diode and 2N3904 transistor to control a relay.

Is 12swg wiring between batteries and the distribution board sufficient for our application?

73

David M0YDH

[G8DKC]

Hi David,

Ok on battery and supply care ideas, will look up your info.

Re Cable.
I would double that, so about 6mm to distribution board, if a fairly short run say 6ft or so.
To link the two batteries together go for almost starter cable, turns them into one big battery.
You never know what you might need later, also chunky wiring for charging.

All this advice, I had better "take heed" myself

73

Peter