Hobbyking 6S 16ah Lipo packs

[eHomer]

I was going to post this in reply to Kinninvie's BBS02 thread, but I thought I'd be better off posting it as a new thread rather than hijacking his.

http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idProduct=68822

Wow... 16 a/h of 22.4 volts for £80 from a UK supplier ?

That sounds like great value to me.

After getting good advice from this forum I used six Hobbyking 4S 5 ah lipo packs to make a 30 ah 15 volt battery for my electric outboard motor, and it turned out really well (on another thread on here somewhere).

I didn't realise they do even bigger packs like this one.

£160 with no extra vat, customs or overseas carriage for 16 a/h of 44.8 volts is very tempting, as I believe my Turnigy ACCUCELL-6 would charge them ?

I believe the comparable cost for a dedicated 48v 10ah lithium bike pack in a holder with BMS is about £300.

Am I right in thinking no BMS or LVC alarm is needed because the bike controller will handle the low voltage cutout during discharge, even using the two 6s packs in series, making the 12s ? (and I suppose the balance leads are just left disconnected then ?)

Also, will my Turnigy charger handle the charging BMS functions with the balance lead connected, ( using one 6s pack at a time I suppose ) ?

The size, weight, and cost of these 16ah 6s packs are very tempting.

As the sealed pack is 6s 2p, is the balance lead connection and intelligent 6s charger as safe for charging as a built in BMS board, like the dedicated cycle battery packs have ?

 

[Deleted member 4366]

I think that's maybe, yes and yes. With lipos, you still have to be careful when you don't know their behaviour. Once you've charged them a few times and seen that they stay nicely balanced, you could dispense with the alarms and use pack voltage control instead, but I'd leave plenty of safety margin - say 42v minimum. A 48v controller will trip the LVC at about 38.5v. If you're going to use that, you better check that it actually works. I prefer a wattmeter because after a couple of cycles, you know how many amp-hours they'll do. Then you can use the wattmeter as a fuel gauge.

You have to charge them one at a time if you leave them connected in series on your bike. If you unplug the series lead, you can charge two at a time using a balance board. You can get 12S chargers, which can charge them while in series.

 

[awol]

Those multistar batteries were not there when you built your battery pack, they a quite new in. They are cheaper because they are only 10C rated which is still ideal for us. I have been tempted to try them too for my next battery.

 

[KirstinS]

Extremely interesting ehomer

I wonder if you can buy empty frame mounted boxes to contain them ?

How would you do so ? In panniers or frame ?

 

[awol]

Extremely interesting ehomer

I wonder if you can buy empty frame mounted boxes to contain them ?

How would you do so ? In panniers or frame ?

eHomer gave me the idea of housing them together in a tuppaware sandwich box with foam for protection.
Then I would use a rear parcel shelf, however I don't need them anywhere near as large capacity so mine will be much lighter than the 16aH ones.

 

[derf]

I think that's maybe, yes and yes. With lipos, you still have to be careful when you don't know their behaviour. Once you've charged them a few times and seen that they stay nicely balanced, you could dispense with the alarms and use pack voltage control instead, but I'd leave plenty of safety margin - say 42v minimum. A 48v controller will trip the LVC at about 38.5v. If you're going to use that, you better check that it actually works. I prefer a wattmeter because after a couple of cycles, you know how many amp-hours they'll do. Then you can use the wattmeter as a fuel gauge.

You have to charge them one at a time if you leave them connected in series on your bike. If you unplug the series lead, you can charge two at a time using a balance board. You can get 12S chargers, which can charge them while in series.

do you know of any good 12s chargers d8veh? it would be great if one could have a "fit it and forget about it" solution involving no more than just plugging the charger in

 

[Deleted member 4366]

The 12S chargers are little more than two 6S ones tied together. Do a search on Endless-sphere. There was a thread about them a few months ago.

 

[Kinninvie]

do you know of any good 12s chargers d8veh? it would be great if one could have a "fit it and forget about it" solution involving no more than just plugging the charger in

.I prefer to remove them from the bike for charging.
That way if they go up in flames the bike doesn't go up with them
I will be charging mine in lipo charging bags which will be inside a steel ammo box which will be in a stone byre so nothing to catch fire even if the worst happens.
Got mine all ordered so should be here Thursday

Mine will be in a plastic case with memory foam round and mounted in a triangle bag.

 

[KirstinS]

eHomer gave me the idea of housing them together in a tuppaware sandwich box with foam for protection.
Then I would use a rear parcel shelf, however I don't need them anywhere near as large capacity so mine will be much lighter than the 16aH ones.

I also only really need 10ah but I'm really looking for a frame solution

Thanks for that though

 

[Kinninvie]

If you want a discount off the full price of these batteries enter buddy code 84AA8F74-B05E-4053-8515-3BAAF33CFA89 when ordering to get a discount of $8.48 (which they will convert to £'s).
Valid for 2 weeks from today!

 

[KirstinS]

Perhaps if a source of BMS boards could be found for 44.4v 12s then a complete plug and play solution could be built ?

I had a look around and found lots for sale that state 12s for 36v battery - which makes no sense at all to me

I have a 36v BMS sitting around - clearly it's 10s not 12s.

 

[derf]

Perhaps if a source of BMS boards could be found for 44.4v 12s then a complete plug and play solution could be built ?

I had a look around and found lots for sale that state 12s for 36v battery - which makes no sense at all to me

I have a 36v BMS sitting around - clearly it's 10s not 12s.

any luck finding a BMS for 12S? if one went completely bananas and got 4 of these it could be around 1.3 kw/h which should at least make for serious range between charging

 

[eHomer]

I think that's maybe, yes and yes. With lipos, you still have to be careful when you don't know their behaviour. Once you've charged them a few times and seen that they stay nicely balanced, you could dispense with the alarms and use pack voltage control instead, but I'd leave plenty of safety margin - say 42v minimum. A 48v controller will trip the LVC at about 38.5v. If you're going to use that, you better check that it actually works. I prefer a wattmeter because after a couple of cycles, you know how many amp-hours they'll do. Then you can use the wattmeter as a fuel gauge.

You have to charge them one at a time if you leave them connected in series on your bike. If you unplug the series lead, you can charge two at a time using a balance board. You can get 12S chargers, which can charge them while in series.

Thanks for the answers, more to mull over !

Yes, my plastic "clip-n-seal" watertight box was a big success, nice and light and padded with foam sheet. I needed extra security because it was actually taken afloat in a canoe.

For charging, I found a metal box in Sainsbury's, (originally intended for gardening tools). It's an ideal size, about 10" by 10" by 24" long, so takes my largest battery packs. I'll take a photo of it and post it on the forum.

 

[Deleted member 4366]

To answer your previous question, 12S for 36v means LiFePO4. I've got loads of BMSs for them. It's a shame you can't adjust the cell voltages. You can get 12S BMSs for lipos. There's a couple of threads about it on ES.

 

[KirstinS]

To answer your previous question, 12S for 36v means LiFePO4. I've got loads of BMSs for them. It's a shame you can't adjust the cell voltages. You can get 12S BMSs for lipos. There's a couple of threads about it on ES.

Ah thanks that makes more sense

I'll check ES later and report back if I can find anything

 

[KirstinS]

Looks like www.bestechpower.com do BMS for just about anything

These are referred to on ES but not sure of actual source/how to buy

 

[Kinninvie]

http://endless-sphere.com/forums/viewtopic.php?f=14&t=63045&p=950637&hilit=multistar#p950637

This one would do me for the BBS02,750 http://www.bestechpower.com/444v12spcmbmspcbforli-ionli-polymerbatterypack/PCB-D132.html

If you need a different rating the full list is here http://www.bestechpower.com/444v12spcmbmspcbforli-ionli-polymerbatterypack/

 

[KirstinS]

Doesn't look like they sell direct - I've emailed them to ask where uk buyers get source

 

[drsolly]

These 16ah, 6s batteries are not quite as cheap as the 4s 5ah hardcase batteries, which are 5% cheaper (comparing watt-hours).

They are lighter, though, by about 25% (per watt-hour), which is very useful for aircraft; also useful for bikes.

More importantly, they're in stock in the UK, whereas the 4s 5ah ones are currently not in stock.

 

[Deleted member 4366]

It's worth paying a bit more to save all the hazardous wiring. You could go a long way very fast with four of them.