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Continue with LiPo or go LifePo4?


#21

Blimey, thanks for all the excellent comments. When I decided to ask on Reflector I also decided to defer any purchase until I had the opportunity to be educated by the collective wisdom.

RE: battery swelling, I will certainly check that - so if there is movement between the film casing and the cells then that is the wrapping bubbling up other than the cells themselves?

RE: taking 4.8AH batteries on a plane - that is a very significant point for me as I am planning on taking batteries to both the Isle of Man and Spain.

I will look into LiHV batteries as well.

Thanks for being such a great community!

Mark.


#22

From the Hobby King site:

LiHV batteries can be charged to 4.35V per cell, higher than normal LiPo batteries which sit at 4.20V. For example, a 4S LiHV pack charged at 4.35V would give you 17.4V. Whereas a Lipo battery on the same charge would only get 16.8V. LiHV batteries also have a lower internal resistance and are less prone to “puffing”.

So I guess a 3 cell would go from 13.05V fully charged to, what 9.6V if max discharge voltage is 3.2V? I guess that brings it more in range of some of the portable equipment - for example it would probably power the MCHF fine, but I’m guessing LifePo4 are still a much better match for commercial 12V equipment.

Mark.


#23

Hi Mark - yes, just give them a squeeze between thumb and forefinger to check. When I over-discharged one of mine and it started to swell, there was no gap between the battery and it’s plastic wrapping. You might have lots more life in your batteries.

I looked at LIHV, but to my mind they seem to be tailored more to the radio control market. Even 100C batteries are available! The sort of loads we put on them, especially with SSB and CW, are very low by comparison to powering radio control models. If I were changing my batteries, I would definitely go for LiFePO4 and with respect to what has been said, 2 x 4200mAH makes better sense to me.

73, Gerald G4OIG

Edit: LiHV will need a different charger to normal LIPO. From reading various articles about them, it seems that they are a bit like Marmite and divide opinions on whether or not they are better.


#24

They didn’t care about my Lipos this year at Edinburgh… I had a 10in tablet, 7in tablet, 817, camera and phone. They were only interested in the 817 and the mass of USB cables.

(Just about to set off for today’s summits)


#25

Just for information you can take two batteries of between 100 Watt hour and 160 Watt hour but you have to contact the carrier and get written permission

Colin


#26

I took the plastic wrap off the worst of my two batteries to check whether it was the wrap or the cells, and it looks like there is definite puffiness in the cells - evidenced by the general expansion of the end not connected together:

When I peeled back the additional plastic layer on the top it was clear there is expansion in the cell although maybe this isn’t considered extreme.

Regardless, I’ll be ordering some new batteries, I’m not taking any chances.

Thanks for all the info once again!


#27

Well Mark, I’d be strapping them up and using them awhile yet… obviously I have been infected by activating for too many years in GM. :wink: The one of mine that swelled was seriously obese and it’s voltage was nowhere near what it should have been, so it went through the total discharge process and was sent to landfill.

You have to be happy with batteries. Carrying LiPO batteries could be deemed to be a significant risk. I am sure some wouldn’t entertain the set up I have developed for the DX S2S events which is based around 16.4AH of LIPO and 20A of NIMH. A veritable bomb by all accounts, but I haven’t been arrested yet!

73, Gerald G4OIG

P.S. I do overlay the LiPOs with an intumescent membrane.


#28

HI Mark

I have two of these Ultra Max 7 amp LiFePo4 batteries. They are now around 4 years old and are still performing well. A young feller like you would not have any problem carrying one or two… Great for radios like the FT-857. They will do 100 watt output without any noticeable sag in voltage. Not sure if they are still available on ebay. The seller I got them from (I recall) was Edmonton, London and each battery came with its own charger. Both chargers still working well.

Hard case is the way to go if you want grunt!

73 Phil G4OBK


#29

Mr Peck:

“You pleaded guilty to carrying an offensive weapon - the minimum mandatory sentence is 6 months custody, However the bench recognise your guilty plea in this case, so the sentence is reduced by one third. So your sentence is reduced to 4 months custody, however because of your previous good character you sentence will also be suspended for 24 months. Keep in touch with the probation service during this time. If you commit another offence in this time it is likely you will go to prison. You may go.”


#30

That’s an amazing and very scary bit of kit - I suspect you’ve not tried that as carry-on luggage yet? :slight_smile:

In the end I went for the LifePo4 's as recommended by @MW0WML - one of the LiPos is now discharging in water, the other I will keep for a while longer.

Note that I went down this road after my SOTA talk when I was originally alerted by a member of FARS who was also into model car racing - he said the battery I have shown above wouldn’t be allowed in a competition due to the swelling and associated risk.

Now of course the use-case for amateur radio is probably significantly less risky in terms of hard physical shock and the chance of puncture, or indeed over-stressing the battery or running it below the safe discharge level, compared to model car or quad-copter usage. However, I am notoriously slopping in my handling practices and charging practices - the ‘protection’ I use for these batteries has traditionally been a plastic bag.

The other obvious issue to be addressed is removing the need for the Buck Converter. When on Blencathra I ended up running my FT-817 on 2.5 watts because the buck converter was shorting out on its’ mount - entirely my own fault but as I said just another point of failure.

Regards, Mark. M0NOM

p.s. thanks for the education - I learnt a new word today: intumescent


#31

A young feller like you would not have any problem carrying one or two

Oh and Phil, I liked you before I met you because of your fantastic WOTA blog, but I’m just getting more fond by the day… :smiley:


#32

Thank you Your Honour. It is good to know that I have friends in high places. :wink:


#33

I’m partial to the Bioenno power packs. Have the 40 AH pack for my EMCOMM rig with a solar panel. Will be setting up my KX2 with a smaller battery and smaller solar rig.


#34

WOW, 40 Amp Bioenno? I think I have battery envy!

Just gave my first Bioenno (9 amp*hr) a good workout this weekend powering a Yaesu FT-817 and a 45 watt amplifier. Well, I used it a few hours a day over the Memorial weekend and it still has plenty of juice. I almost thought I bought too much but then realized at this lightweight and package size it’s hard to have ‘too much’ capacity. The only question I had, when comparing to SLA batteries was “Why did I wait so long to switch?”