Battery question - change from SLA to..
I'm a big guy...350. I put a Brute kit on a Worksman bike last year and I love it but...
I want to ride this to work. It's 20 miles RT. I can charge the bike at work.
Currently I have 48V 12ah SLA (two 24v 12ah in series)
The first and only time I rode to work the batteries gave out about a mile from work. I was able to make it but it was a scare and I want to be sure I have the power available.
On the ride home I pedal more because I don't mind if I sweat. The ride home I pedaled a lot more and the battery indicator turned yellow but did not cut out.
I want enough battery power to make it one way (in the morning when I don't pedal very much) and welcome advice selecting different battery technology.
I got the kit from Electric Rider and they only recommend SLA batteries. They do have a company on their site that sells Nimh batteries but don't really recommend them, but, if you're going to use Nimh that's who they would use.
I've heard/read that LifePo4 batteries may not be able to supply high current for long periods. I've heard that Nimh are sensitive to discharge/charge cycles...
I don't want to change the motor to a higher voltage unless absolutely necessary.
Is the info I've been reading old info?
Should I get Nimh or LifePo4?
Do you think 48v 20ah would be sufficient using either battery type or would 30ah be best?
Sorry for all the questions...thanks for any advice!
Hey BRUT!!Don't worry about asking questions---that is what the forum is mainly for---we help each other out.
What type & size is your motor--hub or what--BLDC?---how many watts?
Ok, so you have a 20 mile round trip but can charge @ the half-way point right? Tou have series/ parallel wired your SLA batteries for 48 Volts & almost did not make the 10 miles. If all you need is to get to work--10 miles range then 4-20amphr SLA's should do it. I am running 4-33 amphr batteries but the bike is being built right now so I cannot honestly tell you what range I get. I designed for 16 to 20 miles range on my 24 Volt trike but only time & testing will tell.
Are you sure you are getting a full charge? Is your charger big enough like about 10 amphr and for SLA batteries---it MUST be for SLA batteries!!!. Are the batteries properly cabled using a minimum of 10 gauge wire but preferably #6 or # 8? To be absolutely sure go to this link---it is GOOD!
You also can consider LiFePo4 batteries. They are less weight so that alone gives you more range in itself. You can more deeply discharge them than SLA's. They have over twice the life of SLA's They cost more but may be cheaper in the long run---almost everyone ends up using them in the end. I suggest you go to this link for them as they are cheapest here. Also, study the types, sizes, whether your come with balancers---you should get them. Email elite power solutions & tell them what size motor, voltage, the weight of you & your trike, the range you want & they will tell you what batteries & charger to buy---lithium requires a special charger. etc. You will have to research how to balance & charge them or you will wreck them.
Did you post the link about the batteries? I'm new and may have missed it.
Thanks again DT98
Sorry, I didn't proof read that post---this is the battery place---look around then email them w/ weight, motor watts, range expected & let them tell you what you need. I think, judging on that you made it to work 4-10 amphr will do it but I think they have 20 amphr---the extrathe20's would give you a good cushion and allow for weakening over age. A GUESTIMATE is 2 amphrs/ mile but that is for a normal weight person on a regular bike---you & the trike will take more. CLICK ON ELITE POWER SOLUTIONS below.
elite power solutions
Good luck & keep me posted---I'll answer the post before this soon.
thanks for the reply and help. In answer to your questions:
I put the kit on the bike last fall so it's not even a year old yet.
The motor is: Crystalyte Phoenix Brute X-5305, 48v, front wheel mount
The controller is: Their 4840 controller (1920 watts)I think the 4840 stands for 48v, 40a
The batteries are: new 12v, 12ah, quantity 4 wired in series for 48v, 12ah.
The wiring was their harness that came with the kit, pre-wired.
The charger came with the kit and I have no reason to question it's size. It seems to charge the batteries just fine.
The kit is good. I am very pleased with the torque and power with me being 350 lbs.
I am going to need more battery power and just can't see going to more/larger SLA batteries due to their weight.
What size of LifePO4 batteries do you think would be good...maybe two 48v, 20ah wired in parallel? Do you think that would require a larger controller? Would you prefer LifePO4 over Nimh?
Thanks again for all the help, DT98
I think that battery size would be fine but I DON'T KNOW!!!---Elite power solutions KNOWS!
Kind of an obvious promo for that other company..
Here's my plug;
I'll take care of your Lithium needs
Plug for another company: Colorado Advanced Battery and their Nilar packs. 1/2 the weight of SLAs for same energy density. They have 24v, 36v and 48v packs available mainly 10Ah and 20Ah configurations built into a rugged package. Their complete specs are here:
Several nice things:
1) designed to be charged with an existing SLA charger!
2) NOT made from prism or tubular cells, see their site for details. More like the Prius battery pack in construction.
3) Packaging is just right for rack mount or frame mounting.
The 24V 10Ah CAB Nilar pack fit very nicely in a Currie 24V rack pack that formerly held two 12V 9Ahr gel cells. Left a good bit of room to stick in a WattsUP meter, spare fuses, and the removable front and rear lights. Pack is still just about 1/2 of its prior weight.
If you order from them, use this code ( ERFADP1 ) to get the XLR to charger plug interface at no charge.
And yes it works VERY well on a 2001 vintage Currie Mountain eBike and 2001 Currie eFolder. On the eFolder, the pack doesn't quite squeeze into the slot the way the SLA pack did because of the vent and thermistor that stick out the side of the Nilar battery. Works fine sitting in the rack of the Mountain eBike. Next up, testing on a Giant LaFree Lite.
What size of LifePO4 batteries do you think would be good...maybe
two 48v, 20ah wired in parallel?
Do you think that would require a larger controller?
Would you prefer LifePO4 over Nimh?
Two 20AH packs in parallel would give you 40AH.
That is a major jump from 12AH and about 60 lbs
of batteries. Overkill if you are only
a mile short of work.
I suggest LiFePO4 packs over the other chemistry.
A 48V20AH pack is under 30 lbs.
That's less than the 12AH Sealed Lead Acid
batteries, with nearly twice the power.
The only down side is that Lithium packs will
not tolerate complete discharge, so you must
disconnect them when not used and you should
keep them about half charge for extended storage
(for those of you cursed with winters).
Regarding the discharge current, the issue is that many supplier are mainly provide 10Amp-20Amp discharge on their LiFePO4 cells quality basic. But there are some LiFePo4 cell which can provide much high discharge current like Headway and A123.
Headway cells and battery pack
You are correct, but in pretty much all cases you
get higher current from LiFePO4 packs than you do
from SLA packs.
I would like to go with A123 cells, but till now
I have not seen the weight to price ratio in line
(You need 16 cells, a BMS, and charger.)
The headway site looks good, 11 lbs for 10AH.
$450 bucks. I wish I knew what shipping costs.
I hate to fake an account just to find out.
The headway packs in this site are 12Ah(38140S) and 20Ah(2P 38120S)
38120S is 10Ah
38140S is 12Ah
This site can check shipping cost just put them in cart and then directly go to shipping estimating. No need to make and account.
Also you can email them directly to see if there is lower shipping methods or place order via email.
We can not get A123 in China region. However there are some A123 cells selling in China. And also some of my customer ask us to provide A123 cells. But as I get news from some selling people involved. Those cells are not from official permit. But some lower quality A123 which are 0.1 or 0.2Ah lower capacity than qualified A123 cell.
Just give everyone some notice before buying these A123 cell which may from China. Just ask the seller before you issue a purchase for A123 if the price is much lower than you can find from others.
Anyway A123 cells are good.