silly question

[Mark Adams]

Hi Gents,

I'm pretty sure I'm mission the obvious here, but what di I need to get for batteries? I can't seem to find specs beyond 6v, paired.

Please help the village idiot!

Mark

[Adrian Harris]

Where to put the batteries is the biggest challenge in the M2/M3. I would measure the location you intend to use and then get a size of battery which will fit.

You'll need two 12V batteries, rather than 6V though.

This might be an ideal model for LiFePO4 batteries, as they're smaller than AGM ones for the same sort of capacity.

Adrian.

[Stephen White]

Mark, to echo what Adrian has said, I did a thread on choice of batteries here:

http://www.armortek.co.uk/Forum3b/viewt ... po4#p42921

I've been very pleased indeed with the LiFePO4 22aH battery n my Centurion. It's smaller, lighter and delivers more consistent and longer lasting power than the lead acid predecessors in my Pz IIi, the downside is the cost. If you compare whole life costs though, they come out pretty much even.

All the best.

Stephen

[Mark Adams]

Thank you! I did a quick search, and came up with these. I should have noted that this (these) are my first RC kits. I've assiduously avoided the hobby til now, due to how potentially addictive it is.

https://www.google.com/shopping/product ... L8BEKYrMAQ

Would these be what I need?

[Stephen White]

Mark, they look OK, they've got the essential built in Battery Management System which you need to protect the cells for exceeding charging and discharging limits and a matched charger. You don't necessarily need two 12v unless you have to split the battery for space reasons. Otherwise, a single 24v battery would be simpler (for charging especially).

I've been using a Tracer 24v 20aH LiFePO4 in my Centurion, which is considerably heavier, and had a full day's running at Bovington Tiger Day and had hardly dented the capacity. I therefore think you could get away with something like a 24v 8aH, although you might ask anyone with a half track to confirm. If yes, how about:

http://www.tracerpower.com/lifepo4-24v- ... -pack.html

All the best.

Stephen

[Robert E Morey]

Mark,
Those batteries would work, but they are very expensive. Also the Amp/hours is low at 7A/hour. I would look at simple Motorcycle or Watercraft battery. I would get the sealed AGM type so they don't leak and can be oriented in any position. LiPO and LiFePO are new technology batteries, and will definitely work but they are expensive. LiPO deliver a lot of power in a small light package - ideal for electric airplanes. But they are expensive and only have 10-15 min run time in flight (depending on throttle use etc). The set you have priced is $100-$125 more than a pair of 12V AGM type battery. My Panther battery were 12V, 22Amp hours and were $90 each. Those would be too large for the M3 - but they make many 12V size battery and many Amp/Hour combination. Higher AMP/hour rating will give generally longer run times. The M3 does have much smaller area for batteries so perhaps a LiPO or newer technology smaller package is better. As suggested a single 24V may be better too and be able to fit "under the hood". I haven't shopped for 24V in the US - they may be a little less common.
Best regards,
Bob

[Mark Adams]

Thanks for all the input! I ended up going with 12Ahr batteries. The extra expense is somewhat moot at this point...