Batteries

[Kevin Hunter]

Apologies if this is discussed in detail elsewhere. Have searched most of the forum and haven't found info.

Anyway, just thinking ahead a little, and wondering what the regulars use or recommend as far as batteries are concerned? I don't have much experience of r/c except smaller "toys". Would imagine a full option Centurion with sound, smoke, lights, crew etc could eat a lot of power. Do you run everything from one source, or have separate power for the radio receiver.

Would appreciate any advice
Thanks,
Kevin

[Steen Vøler]

I run everything on one pair 24v batteries.
For my 12v equipment i have a 24to12volt regulator that powers smoke, lights etc

Cheers
Steen

[Andrea Daviero]

If you use armortek option packs they contain internal BEC (battery eliminator circuit) wich can be used to power the receiver without needing a separate battery.
Armortek electronics works at 24V. If you don't use armortek electronics/motors, you can use every voltage you want, but, remember the Ohm law, more voltage=less current at the same power, less voltage, you need to use more current to have the same results.
However some things are voltage limited. Benedini sound cards for example are limited to 12V, if you use a wireless camera probably it will work with 12V or less.
In all cases, you can have a single battery (24,12,and so on) and use a BEC circuit (eventually with a filter) to power the other things.
There are also adjustable BECs where you can choose the voltage output.

[Dennis Jones]

Hi Andrea,

The Benedini TBS5 will only work up to 5 volts if you put any more than that then you are in to an expensive repair. The Benedini micro will work up to 12 volts.

Kevin,

Most of us use 2 in series 12volt 22 amp/hour or 25 amp/hour batteries you can go up to 35 amp/hour depends on how much room you have got, weight, cost and how much running you expect to do between charges. If you are using Armortek modules then no need for an extra supply for radio. I do quite a bit of running with my tanks an only use 22 amp/hour batteries.

Dennis.

[Andrea Daviero]

Hi Andrea,

The Benedini TBS5 will only work up to 5 volts if you put any more than that then you are in to an expensive repair. The Benedini micro will work up to 12 volts.

Kevin,

Most of us use 2 in series 12volt 22 amp/hour or 25 amp/hour batteries you can go up to 35 amp/hour depends on how much room you have got, weight, cost and how much running you expect to do between charges. If you are using Armortek modules then no need for an extra supply for radio. I do quite a bit of running with my tanks an only use 22 amp/hour batteries.

Dennis.

Hi Dennis, yes, the tbs5 is the only benedini unit requiring 5V, tbsmini and micro (as they have integrated amplifiers) will run up to 12V.

here in Italy most of us are replacing the pair of 12V gel batteries with the more efficient LifePo batteries.

[Kevin Hunter]

Thanks for the info to date gentlemen.
Space in these models is at a premium so I presume 2 car batteries are not an option. What are the alternatives, wheelchair or mobility cart batteries? bike batteries?
Re LiPos I thought they could be unpredictable, leaking, burning etc?
Kevin

[Andrea Daviero]

Depending on the tank, a car battery may result too big, smallest batteries are required.
Gel type batteries, sealed lead acid batteries are the common options, normally a couple of 12v batteries in series.
Some Italian people have replaced their batteries with the 12,8V, 22Ah (true 22Ah) LTE batteries found here:
http://www.lipotech.net/storeindustria/ ... 28255202be
Be aware, do not use the language selection in the website, I tried before posting here and the translation is completely wrong (wrong descriptions, wrong data and so on). Use google translator and you will have a better read with the right data.

I'm using LTF lifepo batteries on my sdkfz7 halftrack, with 20Ah. I can run for most of the day(not a continous use) with almost costant voltage until it is mostly discharged.
When I charge (after about 2 years) the charger still charges over 16-18Ah with a battery not fully flat (no to the lower limit voltage) meanings that I will have that power avaiable fully avaiable for the next time.
With a 7Ah lead acid sealed battery After few months of usage the charger recharges from an almost flat battery less than half of the original 7Ah, this limiting the running time.

Reading on the net, Lifepo batteries (also called Life) are much less exposed to fire, explosion and smoke. Are much safer than LiPo batteries(wich needs to be charged externaly from the model and with safety precautions).
Also the price is becoming low, 119€ (maybe around 90-100£) at the moment for the 22Ah batteries.
The only problem with these batteries is the low voltage. I mean that it can't be discharged under its limit or the battery can be permanently damaged (same for overvoltage) But this is the same for the other batteries (expecially for Lipos) Also the lead acid batteries must not be used under the minimum voltage and armortek electronics has a low voltage protection. (I don't know the cut off value)

[Kevin Hunter]

Thanks once again Andrea.
I misread in your previous post, assumed you meant LiPo (which I have heard of) when you actually wrote LifePo. Due to my ignorance I thought you made an error, so very sorry for that.
Regards
Kevin

[Andrea Daviero]

LiFePo are li-ion batteries similar to the Lipos.
The difference is in the chemical composition, Lifepo are Lithium Iron Phosphate, Lipo uses lithium plus polymers (the polymer can vary from a battery to another).

[Andrea Daviero]

If you have time, you can wait the other user experience with that "new" batteries, At this moment I think I am the only one with a lifepo powered armortek at the moment, other italian guys bought them recently, so we will have some more feedbacks soon.
The LTE batteries have another great advantage, they have an integrated electronics wich balance the cells internally and manage the charging function, this means that you can use your previous car battery charger and safely charge the batteries without needing a much expensive life battery charger.

PS: I have no relation with lipotech company, but till my last search they were offering the best prices and products. I think that if you think to buy a lifepo battery it is better that you do an extended google search to find the best (or nearest) shop for you.

[Steen Vøler]

Is the weight and size on the Lifepro batteries less than on traditional batteries with the same Ah

Cheers
Steen

[Andrea Daviero]

From what I seen by comparing the datasheets with a little search in google, a lead acid gel battery (20Ah) weights around 6-7kgs, the lifepo battery weights around 3kgs (the LTE with the internal electronics)... so the half of the gel batteries.
They have similar weight to the lipo batteries, but I'm not sure they are lighter than them.

[Steen Vøler]

Thanks, that is interesting. I will go that route when I need to replace my standard batteries in the jagdpanther