Lifepro4 batt on order

Hi Paul, yes, I smiled at the thought of using one of those fluffy asbestos things that used to be everywhere (I do know that isn’t what Richard had in mind). Maybe an old radium bed warmer to keep the battery warm too :smile:

Thank you both for your comments, probably time for me to relax and let common sense prevail!

73
Adrian

As my SLAB has come to the end of its life (it will not power my new HF radio) I was inspired to look at these LiFePo batteries. Unfortunately the seem to be permanently out of stock at Hobbyking.
Has anyone successfully received one on backorder, or found another suppllier for a high capacity 4S type?
Otherwise is it OK to buy 2 smaller capacity ones and parallel them up?
Any precautions needed with this?
thanks.

just found a hard cased version little less Ah than mine and little more weight

karl

I have been paralleling 2 X 3cell 5AH Lopos for 3 years, I only parallel immediately before use by completing a Y connection and have 20A auto spade fuses in the positive leg immediately off each battery. I break the Y connection prior to charging. This method also gives me an indication which battery has been used. Sparks are not necessary for this activity. I use X40 connectors rather than power pole. These have proven to be reliable when drawing 20A peak.

Regards
David

May be of use to anyone looking for powerpole connectors pre-made, I was at my local halfords today and came across some for £2.50, I couldn’t resist at that price and bought 2 packs.

http://www.halfords.com/motoring/motorcycling/motorcycle-battery-chargers-accessories/torberry-m6-terminal-ring-connector

73
Graeme’s

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So it looks like powerpole connectors are also known as Torberry style connectors then - that’s interesting.
Good find Graeme.

73 Ed.

Hi Ed

Torberry Connectors are the distributors for Anderson powerpole connectors within the UK, had a quick google check in the halfords before purchase.

73
Graeme

May I offer a word of warning having just goosed an almost virgin LiFePO4 battery. I stupidly left mine connected to my 817 after coming back from holiday; the resulting current drain from the switched-off radio resulted in a totally ruined pack

Been there done that. Twice.

Are you sure it’s really lifepo4 and not lipo? I have seen many batteries advertised on eBay as lifepo4 which are actually lipo technology,

Lifepo puff if they are over discharged. But at least they don’t catch fire at easily :slight_smile:

Absolutely certain: Vapex LF94128 9.9v 3800mAh

I actually use quite a number of LIFePO4 batteries in my model boats, especially when the SLABs I have used in the past have shuffled off this mortal coil, which is why I am so annoyed at myself for forgetting to disconnect it from the 817 :cry:

OOPs that,s expense.

karl

Hmm, that’s surprising Barry. I am fairly certain the 817 switches off when the voltage gets too low to sustain it.

On one occasion I forgot to switch out my 4AH 3S LiPO when I came off a summit. I didn’t realise that I hadn’t disconnected it until I tried to switch on the 817 later in the day on another summit. Unfortunately the spare battery had been left in the car, so I had to use my 2m handheld to qualify the summit. I was able to recharge the battery which had around 2.8V per cell rather than the recommended minimum for a LiPO of 3.7V and it is still working fine.

73, Gerald G4OIG

Plus, don’t forget that leaving the battery connected to an FT-817 has a habit of frying the finals!

Still easily done.

There is no power switch between the drains of the FETS in PA and the supply, only the digital and small signal sections are switched. It’s possible for some current to flow when the set is switched off.

Interesting info on the whys and wherefores of FT817 current consumption here:

Well worth reading!

I’d guess Barry had a rechargeable battery pack in his…

73 de Paul G4MD

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Yes, the same conclusion here. To quote the article - _“If rechargable batteries are installed, the '817 trickle charges the pack at 10-15 milliamps”. Multiply that small 0.015AH rate by the 8 week stay Barry had in the Seychelles and yes that battery would be flattened. :wink:

I wish!!

Yes, the rechargeable pack was inside as well.
Told you I was a sandwich or two short of a picnic :grinning:

Why did he have his 817 when he was there, was he doing LOTA, lagoons on the air?